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Plant Glossary

This online glossary is based on the printed glossary from the Fourth Edition of Plants of the Chicago Region by Swink and Wilhelm (1994). The contents and the illustrated plates (linked from appropriate terms) are used with permission of the publisher, the Indiana Academy of Science. Minor modifications and additions have been made from the print version in order to correct errors as well as make some points more clear. The majority of the terms listed in this glossary are not used in the vPlants written description pages. Other terms, which were deemed necessary to concisely provide clear descriptions have been used and are defined in the glossary for our users. The terms in this glossary are those only with special meaning in a botanical context. Words that users are unfamiliar with that are not listed in this glossary are readily defined in any dictionary, such as the online version of the Merriam-Webster Dictionary.

The definitions given below relate to the usage of these terms with plants. Some of these terms have a somewhat different meaning in relation to other things, such as fungi.

A

A-
— Without; not.
Abaxial
— Said of a surface facing away from the axis of the structure to which it is attached.
Abortive
— Defective; barren (unproductive); not developed.
Abscission
— A clean-cut scar or separating of a leaf from a self-healing.
Acaulescent
— Stemless, or apparently so.
Achene
— A hard, one-seeded, indehiscent nutlet with a tight pericarp. [Plate 11 and Plate 12]
Acicular
— Needle-like. [Plate 3]
Acorn
— The specialized fruit of members of the genus Quercus (oaks) that is composed of a nut with a cap of overlapping rows of scales [Plate 11]
Actinomorphic
Radially symmetrical; capable of being bisected into two or more similar planes. Same as regular[Plate 9]
Acuminate
— Tapering to a slender tip. [Plate 5]
Acute
— Sharp-pointed. [Plate 5]
Adaxial
— Said of a surface facing toward the axis of the structure to which it is attached.
Adherent
— Joined to a dissimilar plant part. Compare coherent.
Adnate
— Same as adherent.
Adventitious
— Sprouting or growing from unusual or abnormal places, such as roots originating from a stem, or buds appearing about wounds.
Aerial
— Said of structures originating above ground.
Aggregated
— Crowded together. [Plate 11]
Allopatric
— Occupying different, though sometimes adjacent, regions.
Alluvium
— Sands, silts, et cetera deposited by gradually moving water.
Alternate
— One after the other along an axis; not opposite. [Plate 2]
Ament
— A dry, usually elongate often drooping, scaly spike bearing imperfect flowers; a catkin. A frequent feature of woody plants. [Plate 8]
Anastomose
— To interconnect, such as the veins of a leaf.
Anastomosing
— Connecting and intersecting, forming a network.
Androecium
— The staminate portions of the flower. Compare with gynoecium.
Androgynous
— With staminate flowers situated above the pistillate ones in the same inflorescence.
Angiosperm
— Flowering plant producing seeds enclosed in a structure derived from the ovary.
Angulate
— Having angles.
Annual
— A plant which completes its life cycle in one year or less.
Annulus
— Tissue forming a ring or arranged in a circle.
Anterior
— On the side away from the main stem; abaxial.
Anther
— The pollen-bearing portion of the stamen. [Plate 9]
Anthesis
— Time of the year during which the anthers are dehiscing and the stigmas are receptive to pollen; in a looser sense, the time of flowering.
Antrorse
— Directed forward or upward. [Plate 6]
Aparinaceous
— Scratchy; clingy.
Apetalous
— Having no petals.
Apex
— The tip; end. [Plate 2]
Apical
— Pertaining to the apex.
Apiculate
— Abruptly short-pointed. [Plate 5]
Apiculus
— Abruptly short-beaked or pointed.
Appressed
— Lying flat against a surface.
Aquatic
— A plant which carries out its life cycle in water.
Arachnoid
— Cobweb-like.
Arcuate
— Arching. [Plate 5]
Areola
— A small space on or near the surface of some vegetative organ, usually formed by anastomosing veins.
Areolae
— The spaces between the veins of a leaf or some similar structure.
Aril
— An appendage growing out from a seed.
Arillate
— Having an aril.
Aristate
Awned; tipped by a stiff bristle. [Plate 5]
Aromatic
— Having a fragrant smell, sometimes only if broken or crushed.
Article
— Section of a legume pod, separated from other sections by a constriction or partition.
Articulation
— A joint.
Ascending
— Growing or directed in an upward direction, or at least tending to. [Plate 1]
Asymmetrical
— Unequally developed on either side of a common axis. Opposite of symmetrical.
Atom
— Small, usually resinous, dot or gland.
Atomate
— Having small, usually resinous, dots or glands.
Attenuate
— Gradually tapered to a slender tip. [Plate 5]
Auricle
— An ear-shaped appendage or lobe (such often being quite small).
Auriculate
— With an ear-shaped flange or lobe. [Plate 5]
Autecology
— Pertaining to the ecology of an individual species.
Awn
— A stiff bristle, usually situated at the tip of a leaf or perianth element, or (in grasses), at the tip of a glume or lemma.
Axil
— The area or angle formed between the base of an organ and the structure from which it originated. Such as the upper angle between the leaf base and the stem.
Axillary
— Pertaining to the axil.
Axis
— The central part of a longitudinal support (usually of a stem or inflorescence) on which organs or parts are arranged.
B

Barbellate
— Beset with fine barbs. [Plate 6]
Barren
— Land with sparse vegetation, often with bedrock at or very near the surface (especially in mountainous states, often populated with scrubby pines).
Basal
— Pertaining to the base of the plant or some organ of the plant.
Basifixed
— Attached by the base.
Beak
— A slender terminal process, usually abruptly differentiated from the general outline of the organ from which it originates; usually applied to fruits and pistils.
Berry
— A usually fleshy or pulpy fruit, typically with two or more seeds developed from a single ovary. [Plate 11]
Biconvex
Convex on both surfaces.
Bidentate
— Having two teeth.
Biennial
— A plant which requires two years to complete a life cycle, the first year typically forming a rosette, the second year forming an inflorescence.
Bifid
Cleft into two parts, usually at the summit of some organ.
Bilabiate
— Two-lipped; most often applied to zygomorphic perianths. [Plate 11]
Bilateral
— Having two equal sides on either side of an axis.
Bilaterally symmetrical
— Referring to a calyx or corolla that is zygomorphic, capable of being divided into two equal halves along one plane only. [Plate 9]
Bilobed
— Having two lobes.
Bipinnate
— Twice pinnately compound. [Plate 2]
Bipinnatifid
— Twice pinnatifid.
Biternate
— Twice ternate; when the divisions of a ternate leaf are divided into three. [Plate 2]
Bivalved
— Having two sides or units originating at a common point.
Bladder
— An inflated sac or receptacle containing a fluid.
Blade
— The expanded portion of a foliar or floral organ.
Bloom
— A whitish powdery covering of the surface, often of a waxy nature.
Blunt
Obtuse, round-tipped.
Bog
— A wetland, usually peaty, in which the substrate is typically acid.
Bole
— A strong unbranched caudex; the trunk of a tree.
Boreal
— Northern.
Bract
— A reduced leaf or scale, typically one which subtends a pedicel or inflorescence, but it also can refer to minute leaves on a stem. [Plate 9]
Bracteal
— Pertaining to a bract.
Bracteate
— Having bracts.
Bracteole
— A small bract, typically that which subtends a flower, the pedicel of which is already subtended by a bract.
Bractlet
— A secondary bract, as one upon the pedicel of a flower.
Branchlet
— A division of a branch, smaller than the main branch.
Bristle
— Stiff hair or trichome.
Bristly
— With bristles. [Plate 7]
Bronzing
— Referring especially to the color of foliage after a winter; usually a metallic bronze or coppery color.
Bud
— Very young developing tissue enclosed in scales or valves. [Plate 2 and [Plate 7]
Bulb
— A short, often subglobose, stem surrounded by scales or modified leaves, typically underground.
Bulbil
— A small, usually axillary bulb-like organ. [Plate 7]
Bulblet
— A small bulbiform organ, particularly one proliferating from a leaf axil or sterile flower. [Plate 7]
Bulbous
— Having the character of a bulb.
Bullate
— Blistered or puckered.
Bur
— A spiny or prickly, usually dry, fruit or cluster of fruits.
C

Caducous
— Falling off early or prematurely; deciduous.
Caespitose
— See cespitose.
Calcareous
— Limy; as in water or soil made basic by a prevailing amount of calcium ions.
Calciphilous
— Lime-loving.
Callosity
— A hardened thickening.
Callous
— Having the texture of a callus.
Callus
— A hard protuberance or callosity; often (in grasses) the swelling at the base or joint of insertion of the lemma or palea.
Calyx
— The outer, usually green, series of perianth parts; the sepals taken collectively.
Cambium
— Thin layer of meristematic cells, typically that which gives rise to secondary xylem or phloem.
Campanulate
— Bell-shaped or cup-shaped, typically with a flared or enhanced rim. [Plate 10]
Canaliculate
— Having a groove or channel.
Cancellate
— Having a net-like or sculptured surface.
Cane
— The elongated new shoot of shrubs, such as in Rubus.
Canescent
— Densely beset with matted, often grayish-pubescent, hairs. [Plate 6]
Capillary
— Hair-like.
Capitate
Head-like; very densely clustered.
Capitulum
— A small head of flowers. [Plate 8]
Capsule
— A dry dehiscent fruit composed of two or more carpels. [Plate 11]
Carinate
Keeled. [Plate 10]
Carpel
— A pistil, or one of the units of a compound pistil.
Carpellate
— Having carpels.
Cartilaginous
— Cartilage-like; firm and tough but neither rigid nor bony.
Caryopsis
— In grasses, a seed-like fruit with a thin pericarp; a grain. [Plate 12]
Catkin
— Same as ament. [Plate 8]
Caudate
— Tail-like, or bearing a tail-like appendage. [Plate 5]
Caudex
— The ligneous or woody base or a perennial plant.
Caulescent
— Having an above-ground stem.
Cauline
— Pertaining to the stem or features of the stem.
Cespitose
Tufted, usually referring to the compact arrangement of the stem bases with respect to each other and their position in the soil; sometimes spelled caespitose.
Chaff
— Dry, scaly, often small, bracts; typically referring to those scales subtending the individual flowers in composite heads.
Chalaza
— The basal part of an ovule where it is attached to the funiculus.
Chambered
— Areas in the hollow pith of twigs where vertical walls occur at close intervals. [Plate 7]
Chartaceous
— Thin, but firm; resembling the more ancient writing paper.
Chink
— A modified pore, usually involving an opening in the anther.
Chlorophyll
— The green photosynthetic pigment.
Cilia
— Hairs or slender bristles confined to the margins of some organ.
Ciliate
— Fringed with cilia; bearing cilia on the margins. [Plate 4]
Ciliolate
— Minutely ciliate.
Ciliolulate
— Minutely ciliolulate.
Cinereous
— Ash-gray colored.
Circinate
— Rolled coilwise from the top downward, as in unopened fern fronds.
Circumscissile
— Pertaining to the dehiscence of a capsule (pyxis) which opens by a circular, horizontal line, the top usually coming off as a lid. [Plate 11]
Clammy
— Sticky-hairy.
Clasping
— Tending to encircle or invest, as in the base of a leaf which forms partly around the stem to which it is attached. [Plate 5]
Clavate
— Club-shaped; dilated upwards.
Claw
— The narrowed base or stalk of some petals.
Cleft
Distinctly divided or incised, usually to about the middle. [Plate 4]
Cleistogamous
— Fertilized in the bud, without the opening of the flower.
Clone
— A group of individuals, resulting from vegetative multiplication; any plant propagated vegetatively and therefore, presumably a duplicate of its parent.
Coarse
— Rough.
Column
— Sheath or structure formed by the uniting of stamens around the pistil.
Columnar
— Shaped like a column or pillar.
Coma
— A dense tuft of hairs, often resembling a beard, attached to a seed.
Comose
— Bearded, with a coma. [Plate 6]
Compound
— Pertaining to leaves which are divided into distinct leaflets.
Compressed
— Strongly flattened, especially laterally.
Concave
— Hollow; in the context of the interior of a curved surface; opposite of convex.
Concentric
— Two or more circles having a center in common.
Conduplicate
— Folded together lengthwise.
Cone
— Three-dimensional object with a circular base, the sides all tapering to a point at the summit; the fruit of pines and their relatives; spore case of Equisetum. Compare strobile.
Conical
Cone-shaped.
Coniferous
Cone-bearing.
Connate
— Fused or united to a similar plant part. Compare adnate.
Connective
— The part of the stamen which connects the two parts of an anther.
Connivent
— Coming together; meeting at a common point but not fused.
Conspecific
— Said of two or more taxa belonging to the same species.
Contracted
— Abruptly narrowed or reduced.
Convex
— Curved or rounded, as the exterior of a circular form viewed from without; opposite of concave.
Convolute
— Rolled up longitudinally.
Coralline
— White and coral-like.
Cordate
— Heart-shaped. [Plate 3 and Plate 5]
Coriaceous
— Leather-like.
Corm
— A solid, bulb-like part, usually subterranean, as the "bulb" of a crocus or gladiolus. [Plate 1]
Cormose
— Bearing corms.
Corniculate
— Furnished with a little horn.
Corolla
— The inner series of perianth parts, often colored; the petals taken collectively.
Corona
— A short-cylindric or crown-like modification of the corolla; also, a small crown in the throat of a corolla, as in Narcissus.
Coronate
— With a corona. [Plate 10]
Corrugated
— Wrinkled or folded longitudinally.
Corymb
— An arrangement of the inflorescence in which stalked flowers are situated along a central axis, but with the flowers all nearly or quite attaining the same elevation with respect to each other, the oldest at the edges. [Plate 8]
Corymbiform
— Resembling a corymb.
Corymbose
Corymb-like.
Corymbulose
— Resembling small corymbs.
Costate
— Ribbed; having one or longitudinal nerves.
Cottony
— With the consistency of cotton.
Cotyledon
— A seed leaf; the first leaf (or leaves) to appear during the development of a seedling.
Crateriform
— Saucer-shaped or cup-shaped (usually shallowly so).
Crenate
— Very shallowly toothed with broad, blunt teeth. [Plate 4]
Crenulate
— Minutely crenate. [Plate 4]
Crest
— A ridge or strong keel, typically along one side of an achene or nutlet; also, the elevated portion of a petal, as in some Iris.
Crown
— That portion of a stem at the ground surface; also, in the Asteraceae family, scales or awns at the summit of an achene.
Cruciform
— Cross-shaped. [Plate 10]
Cucullate
Hood-shaped.
Culm
— The stem of grasses, sedges, and rushes. [Plate 12]
Cultivar
— A cultivated variation.
Cuneate
— Wedge-shaped. [Plate 5]
Cusp
— An abrupt point or tooth.
Cuspidate
— Bearing a cusp. [Plate 5]
Cuticle
— An often waxy, outer film of dead epidermal cells.
Cyathium
— The cup-like involucre characteristic of the genus Euphorbia.
Cylindrical
— Shaped like a cylinder.
Cyme
— An often flat-topped inflorescence, the central floret of which blooms first. [Plate 8]
Cymose
— Resembling a cyme.
Cymule
— A small, often compacted and usually few-flowered, cyme.
D

Deciduous
— Pertaining to plants which shed their herbaceous tissues after one year's growth; not evergreen; caducous.
Decompound
— Divided or compound more than once.
Decumbent
— Trailing along the ground but with the inflorescence or summit of the stem ascending or erect. [Plate 1]
Decurrent
— Usually pertaining to some flat, foliar organ, the tissue of which continues beyond its base down an elongate axis (usually a stem or petiole).
Decussate
Opposite leaves in four rows up and down the stem; alternating in pairs at right angles.
Deflexed
— Abruptly directed downward; reflexed.
Dehiscent
— Said of a fruit or anther that opens by sutures, valves, slits, pores, etc.
Dehiscence
— The opening of a fruit or anther by sutures, valves, slits, pores, etc.
Deltoid
— Triangular. [Plate 3]
Dentate
Toothed, the teeth perpendicular to the margin. [Plate 4]
Denticulate
— Minutely dentate. [Plate 4]
Depauperate
— Poor; with little sustenance or vigor.
Determinate
Inflorescence whose terminal flowers open first. See indeterminate.
Diadelphous
— Combined into two, often unequal sets; primarily spoken of in connection with the Fabaceae family, where the flowers typically have a set of stamens consisting of nine and another consisting of only one stamen.
Diaphragm
— A dividing membrane or partition, a feature of chambered pith.
Dichasium
— A cyme with two lateral axes.
Dichotomous
— Forking regularly in two directions.
Dicot
Angiosperm with 2 seed leaves.
Diffuse
— Widely or loosely spreading.
Digitate
— Typically referring to a compound leaf in which the leaflets originate from a common point at the apex of a petiole; also spoken of a flower cluster.
Dilated
— Expanded or enlarged.
Dimorphic
— Having two forms.
Dioecious
— Pertaining to plants, individuals of which bear either staminate or pistillate flowers but not both.
Disarticulate
— To separate.
Disk or disc
— The central portion of a capitate inflorescence, or the receptacle of such an inflorescence; also, a structure formed by the coalescence of stigmas as in the Papaveraceae family; also, the development of the receptacle at or around the base of a petals, as in Acer and Euonymus. [Plate 9 and [Plate 12]
Disk flowers
— In the Asteraceae family, the central, tubular flowers of the head. Compare ray flower.
Dissected
— Cut or divided into narrow segments.
Distal
— The direction or point away from the point of attachment.
Distichous
— Arranged in two vertical series; two-ranked.
Distigmatic
— Bearing two stigmas.
Distinct
— Separate, and usually evident.
Divaricate
— Widely spreading or divergent.
Divergent
— Directed away from each other.
Dorsal
— Relating to the back or outer surface of an organ. Compare ventral
Downy
— Covered with soft hair.
Drupe
— A typically one-locular, fleshy or pulpy fruit with a hard or stony center.
Drupelet
— A small drupe. [Plate 11]
E

E- or Ex
— Without; not.
Ebracteate
— Without bracts.
Eccentric
— Off center, or one-sided.
Echinate
— Bearing stout, often bluntish, spines or prickles. [Plate 6]
Eciliate
— Without cilia.
Eglandular
— Without glands.
Elevated
— Raised, often forming a ridge.
Ellipsoid
— Solid but with an elliptical outline.
Elliptic
— A circular shape which has been laterally compressed, widest about the middle. [Plate 3]
Elongate
— Drawn out into a form much longer than wide.
Emarginate
— With a shallow notch at the tip. [Plate 5]
Emergent
— Pertaining to aquatic plants which have some portion of the plant extended out of the water.
Emersed
— Above water.
Endemic
— Confined to a small geographic area.
Endosperm
— In a seed, the reserve food stored around, or next to, the embryo.
Entire
— Pertaining to margins without crenation, serration, or dentition; even though the margin may be variously ciliate or pubescent. [Plate 4]
Ephemeral
— Lasting for one day or less.
Epidermis
— The superficial layer of cells.
Epigynous
— Flower with the calyx situated on the ovary. [Plate 9]
Equitant
— Pertaining to the two-ranked arrangement of usually conduplicate leaves, overlapping in two ranks.
Erect
— Upright.
Erose
— Pertaining to margins which appear unevenly cut or incised, as if eroded or eaten.
Evanescent
— Fading, disappearing in time.
Evergreen
— Refers to having green foliage throughout the year.
Excurrent
— Usually in reference to veins and nerves which run beyond the margin of the organ from which it originates; often as an awn or bristle.
Exfoliating
— Loosely shedding in thin or stringy layers.
Exserted
— Prolonged beyond the rim of an enveloping or confining structure.
Extrorse
— Looking or facing outward.
F

Face
— A flat side.
Falcate
— Sickle-shaped; slenderly curved and tapering to a usually sharp tip. [Plate 3]
Falls
— Outer whorl or series of perianth parts of an iridaceous flower, often broader than those of the inner series and, in some Iris, drooping or flexuous.
Farinose
— Resembling farina; typically used to describe the white-mealy, strongly modified hairs in the genus Chenopodium. [Plate 6]
Fascicle
— A cluster or bundle. [Plate 2]
Fasciculate
— With fascicles.
Fastigiate
— Usually in reference to branches which are stiffly erect; neither divaricate nor divergent.
Fen
— A general term used in reference to habitats which are calcareous in nature and which are fed throughout the year by a flow of water at or just beneath the surface.
Ferruginous
— Rust-colored.
Fertile
— Capable of reproducing sexually.
Fetid
— Having a disagreeable odor.
Fibrillose
— Beset or provided with numerous fine fibers.
Fibrous
— Referring usually to a much branched root system with progressively smaller branches. [Plate 1]
Fiddlehead
— Referring to the unusual circinate unrolling of fronds, in many ferns.
Filament
Anther-bearing stalk of the stamen. [Plate 9]
Filiform
— Very slender, thread-shaped; usually terete in cross section.
Fimbriate
— Fringed.
Fimbriolate
— With tiny fringes.
Fistulose
— Hollow, often pertaining to stems with hollow centers.
Flabelliform
— Fan-like.
Flaccid
— Very limber, without apparent support.
Flange
— A bit of projecting tissue.
Flexuous
— Flexible; easily bent this way and that.
Floccose
— Copiously beset with tangled woolly hairs. [Plate 6]
Floret
— A single small flower, usually a member of a cluster, such as a head; used particularly in grasses (Poaceae family) and composites (Asteraceae family).
Floriferous
— Bearing flowers.
Fluted
— With a parallel series of grooves.
Foliaceous
— Leafy; leaf-like.
Foliate
— With leaves. [Plate 2]
Foliolate
— Having leaflets; often used with a prefix, such as trifoliolate. [Plate 2]
Follicle
— A dry fruit consisting of a single carpel and dehiscing along only one suture. [Plate 11]
-form
— Suffix meaning like or resembling.
Forma
— A infraspecific taxonomic entity, usually involving single-gene traits such as flower or fruit color.
Friable
— Easily crumbled; fragile.
Frond
— The foliaceous blade of a fern leaf.
Fruit
— That structure which bears the seeds.
Fruticose
Shrubby or shrub-like and also woody.
Fugacious
— Falling away early.
Fulvous
— Tawny.
Funnelform
— Shaped approximately like a funnel; sometimes called infundibuliform. [Plate 10]
Furcate
— Forked.
Fuscous
— Grayish-brown.
Fusiform
— Spindle-shaped; swollen in the middle and gradually narrowed toward each end.
G

Galeate
Hood-like; helmet-shaped. [Plate 10]
Geniculate
— Knee-like; usually referring to the alternate, abrupt bends at the nodes of some stems; also referring to bent awns.
Genus
— A group of related species, as the genus Ulmus (elm), the genus Syringa (lilac), embracing respectively all kinds of elms and all kinds of lilacs.
Gibbous
— Swollen on one side; protuberant, often interrupting the radial symmetry of a structure. [Plate 10]
Glabrate or Glabrescent
— Becoming smooth.
Glabrous
— Smooth, in the sense of not possessing hairs.
Gland
— A general term applying to any number of small protuberances, viscid dots, or secretions.
Glandular
— With glands. [Plate 6]
Glaucescent
— Weakly glaucous.
Glaucous
— Covered by a white or pale, often waxy, bloom.
Globose
— Spherical; globe-like.
Globular
— Circular.
Glochidiate
— With minute barbed bristles. [Plate 7]
Glomerate
— Tightly clustered, usually in reference to compact clusters of short-stalked flowers.
Glomerulate
— Similar to glomerate, but with smaller clusters.
Glomerule
— A small, compact cluster. [Plate 8]
Glume
— The lowest two (sometimes one) empty scales subtending the usually fertile scales in grass spikelets. [Plate 12]
Glutinous
— Covered with a sticky exudation.
Grain
— The fruit of most grasses; a caryopsis.
Granular
— Appearing to consist of tiny grains.
Granulate
Granular.
Granulose
Granular.
Grit Cells
— The hard, almost stony, cells, found in some fruits, especially pears.
Gymnosperm
— Seed-bearing plant in which the ovules are borne on open scales.
Gynoecium
— The pistil or collective pistils of a flower; the female portions of a flower as a whole -- the corresponding term for stamens is the androecium.
H

Halophilic
— Preferring saline soils.
Halophyte
— A plant that grows in saline soils.
Hastate
— Resembling an arrowhead, particularly with respect to the lobed basal portion, which is usually at about right angles to the main portion. [Plate 3and Plate 5]
Hastiform
— More or less hastate.
Haustorium
— In parasitic plants, a specialized outgrowth of a stem or root, serving for the absorption of food, as in the dodders.
— A dense, compact cluster of mostly sessile flowers. [Plate 8] Also used to describe the inflorescence in the Asteraceae family. [Plate 12]
Helicoid
— Refers to racemes or spikes which are coiled from the tip downward with successive lateral branches arising on the same side. [Plate 8]
Helmet
— A hood-shaped organ, usually a petal, best exemplified in the genus Aconitum.
Herb
— A non-woody, non-grass-like plant.
Herbaceous
— Not woody.
Herbage
— Referring to green leaves and shoots.
Hilum
— The scar or point of attachment of the seed.
Hip
— The unusual fruit exemplified by the genus Rosa.
Hirsute
— Beset with stiff or stiffish, usually straight, hairs. [Plate 6 and Plate 7]
Hirsutulous
— Slightly hirsute.
Hirtellous
— Minutely hirsute. [Plate 6]
Hispid
Coarsely hirsute or bristly-hairy. [Plate 6 and Plate 7]
Hispidulous
— Minutely hispid.
Hoary
Pubescent with close, fine, usually grayish or whitish, hairs.
Hood
— Specifically, that part of the milkweed flower in which the stamens are greatly modified into hood-like organs; in general, an organ which is arched or concave. [Plate 10]
Horn
— A incurved body often present in the hooded body of milkweed flowers.
Humifuse
— Spreading over the ground.
Hummock
— A small, low mound in an otherwise wet plant community.
Hyaline
— Transparent or translucent.
Hybrid
— The progeny of sexual reproduction between two different, recognized species.
Hydromesophytic
— Referring to the wet mesophytic swamps behind the high dunes near Lake Michigan.
Hypanthium
— Floral tube formed by the adnation of the sepals, petals, and stamens; most commonly tubular and simulating a calyx tube.
Hypogynium
— The disk-like structure subtending the ovary in the genus Scleria.
Hypogynous
— Flower with the calyx situated below the ovary. [Plate 9]
I

Imbricate
— A general term which applies under various conditions where one organ, or series of organs, overlaps another organ or series of organs; as in roof shingles. [Plate 2]
Immaculate
— Without spots. Compare with maculate.
Immersed
— Growing beneath the surface of the water.
Imperfect
— Pertaining to a flower in which there is but one set of sex organs; i.e., those flowers which are either strictly male or strictly female; imperfect flowers occur in both monoecious and dioecious plants.
Impressed
— Sunken in; situated inferior to the surface of a blade, usually in reference to veins which are neither flush with nor raised above the surface of the blade or organ.
Incised
— Deeply cut or divided, usually irregularly. [Plate 4]
Included
— Contained within, usually in reference to stamens, pistils, or capsules which do not surpass or exceed the calyx or corolla in length.
Incurved
— Curled or directed inward, such as hairs, the tips of which curve back toward the stem or surface of an organ.
Indehiscent
— Not opening at maturity; a term generally referring to some fruits.
Indeterminate
Inflorescence whose terminal flowers open last. See determinate.
Indument
— Hairy or pubescent, usually rather heavy, covering.
Indurated
— Hardened.
Indusium
— A delicate flap or covering connected to the sorus in ferns.
Inferior
— In reference to an organ which appears subordinate to or lower than another similar organ; in reference to an ovary, at least the sides of which are adnate to the hypanthium. [Plate 9]
Infertile
Sterile; unable to produce seeds.
Inflated
— Blown up or dilated as if by air; bladder-like.
Inflexed
— Bent inward.
Inflorescence
— The discrete flowering portion or portions of a plant; a flower cluster. [Plate 8 and Plate 12]
Infra-
— Prefix meaning beneath, or less than, or within. Opposite of supra-.
Infraspecific
— Pertaining to any taxon within a species, such as a subspecies, variety, or form. Compare to interspecific and intraspecific.
Infructescence
— The fruiting inflorescence.
Inrolled
— Said of leaf margins rolled inward toward the midrib.
Insipid
— Without taste or flavor.
Inter-
— Prefix meaning between, or among.
Internode
— That portion of the stem other than the node; the distance between two nodes. [Plate 7]
Interspecific
— Among species or between two species. Compare to infraspecific and intraspecific.
Interstitial
— That space which is between or among two or more discriminate structures; in the Rosaceae family, referring to the small leaflets between two large leaflets on the rachis.
Intra-
— Prefix meaning within.
Intraspecific
— Referring to a taxonomic entity with a species. Compare to infraspecific and interspecific.
Intrastaminal
— Among the stamens.
Introrse
— Turned inward or toward the axis.
Invaginated
— Sunken inwardly; used in connection with the achene in Carex.
Involucel
— A secondary involucre, such as that subtending an umbellet in the Apiaceae family. [Plate 8]
Involucral
— Pertaining to an involucre.
Involucrate
— Having an involucre.
Involucre
— A whorl or imbricated series of bracts, often appearing somewhat calyx-like, typically subtending a flower cluster or a solitary flower. [Plate 8]
Involute
— Leaf margins rolled toward the upper surface of the midrib. [Plate 4]
Irregular
— Referring to a calyx or corolla which is bilaterally symmetrical, capable of being divided into two equal halves along only one plane. Same as zygomorphic.
Isodiametric
— Shapes with sides or diameters of nearly equal lengths.
J

Jointed
— With nodes, or points of real or apparent articulation.
K

Keel
— A longitudinal fold or ridge; in the Fabaceae family, the two anterior united petals of a papilionaceous flower -- a flower shaped like a sweet pea blossom.
L

Lacerate
— Unevenly cut or incised. [Plate 4]
Laciniate
— Deeply and sharply slashed into slender segments. [Plate 4]
Lacuna
— Defined space.
Lamellae
— Thin flat plates or laterally flattened ridges.
Lamina
— Blade, usually of a leaf. [Plate 2]
Lanate
— Densely white woolly-pubescent. [Plate 6]
Lanceolate
— Lance-shaped, broadest below the middle, long-tapering above the middle, several times longer than wide. See oblanceolate[Plate 3]
Lanuginose
Woolly or cottony; downy, the hairs somewhat shorter than in lanate.
Lanulose
— Very short-woolly.
Lateral
— Pertaining to the sides.
Latex
— The milky juice (or highly colored juice) of some plants.
Lax
— General term meaning open, loose, without clear form or shape, or scattered, depending on the context.
Leaf
— Usually a blade-like organ attached to the stem, often by a petiole or sheath, and commonly functioning as a principal organ in photosynthesis and transpiration. Leaves characteristically subtend buds and extend from the stem in various planes. See also leaflet. A leaf axil is the upper angle between a leaf petiole, or sessile leaf base, and the node from which it grows. A leaf scar is formed on a twig following the fall of a leaf, usually revealing the pattern of vascular bundles in the leaf trace.
Leaflet
— One of the discriminate segments of the compound leaf of a dicotyledonous plant. Leaflets may resemble leaves, but differ principally in that buds are not found in the axils of leaflets, and that leaflets all lie in the same plane. [Plate 2]
Legume
— The fruit in the Fabaceae family, produced from a one-celled ovary, and typically splitting along both sutures; as in the pea pod. [Plate 11]
Lemma
— The lowermost of the two scales forming the floret in a grass spikelet -- the uppermost, less easily seen, is called the palea. [Plate 12]
Lenticel
— A corky spot on young bark, corresponding functionally to a stoma on a leaf. [Plate 7]
Lenticular
— Lens-shaped; two-sided, with the faces convex.
Lepidote
— Surfaced with small scurfy scales. [Plate 6]
Ligneous
— Woody.
Ligulate
— Bearing a ligule. [Plate 10]
Ligule
— In the Asteraceae family, pertaining to the dilated or flattened, spreading limb of the composite ray flower; in other families, such as Poaceae family, an extension, often scarious, of the summit of the leaf sheath. [Plate 12]
Limb
— The expanded portion of a corolla above the throat; the expanded portion of any petal.
Linear
— Very long and narrow, with nearly or quite parallel margins. [Plate 3]
Lip
— Referring to either the upper or lower lip of a bilabiate corolla; the principal, seemingly lower, petal in the Orchidaceae.
Lobe
— Any segment or division, particularly if blunt. [Plate 4]
Lobulate
— Bearing lobes.
Locular
— Having locules.
Locule
— A discriminate cavity or space within an ovary, fruit, or anther.
Loculicidal
— Pertaining to a capsule which dehisces along the dorsal suture of each locule, thus opening directly into the cavity. [Plate 11]
Locus
— Place.
Loment
— Specifically applied to the series of one-seeded articles of a fruit in the genus Desmodium. [Plate 11]
Longiligulate
— With long ligules.
Lustrous
— Shiny.
Lyrate
Pinnately lobed into large, broad lobes, the terminal one typically noticeably larger than the reduced lateral ones. [Plate 3]
M

Maculate
— Spotted. Compare with immaculate.
Malodorous
— Foul-smelling.
Malpighian
— Spoken of hairs which are straight and attached by the middle, and typically appressed to the leaf surface.
Marcescent
— Withering but persistent, usually remaining green.
Margin
— Edge. [Plate 2]
Marine
— Referring to an aquatic habitat in salt water.
Marly
— Very limy, often with calcium carbonate concretions at or near the surface.
Mealy
— See farinose.
Megaspore
— The larger type of haploid spore (when two sizes are present) which gives rise to the female gametophyte; the other called a microspore.
Membranaceous
— Membrane-like; very thin, flimsy, and often more or less translucent.
Mericarp
— The discriminate units of a schizocarp which ultimately splits apart into two individual nutlets, usually referring to units of the fruits of the parsley family.
-merous
— A suffix pertaining to the discriminate portions into which a floral organ or series of organs can be divided; for example, a flower with 5 sepals, 5 petals, and 10 stamens can be said to be 5-merous.
Mesic
— A microclimatic term which refers to an area in which the soils are usually well drained, but contain a lot of moisture for all or much of the year; such areas typically occur on north or east-facing exposures. Compare to xeric.
Mesophytic
— Refers to plant species or plant communities which grow under mesic conditions.
Microspore
— Haploid spore which gives rise to the male gametophyte; other being called megaspore.
Midnerve, Midrib, Midvein
— The central or principal vein of a foliar or bracteal organ, or of a sepal or petal. [Plate 2]
Milky
— Like a thick white juice.
Minerotrophic
— Rich in calcium and magnesium carbonate.
Monadelphous
— Spoken of stamens united by their filaments into a tube or column.
Moniliform
— Appearing as a string of beads.
Monocot
Angiospermous plant having only one cotyledon.
Monoecious
— Pertaining to plants, individuals of which bear both staminate and pistillate flowers but not perfect flowers.
Moniliform
— Resembling a string of beads; cylindrical, with contractions at regular intervals.
Mottled
— Covered in part with spots, areas, or lines of different color than the main surface.
Mucro
— A short and small abrupt tip.
Mucronate
— With a short, abrupt tip. [Plate 5]
Mucronulate
— Minutely mucronate.
Multifid
Cleft into many lobes or segments.
Muricate
— Copiously beset with hard, often sharp, tubercles. [Plate 6]
N

Native
— Inherent and original to an area.
Nectar
— A sweet substance typically produced by flowers which are insect-pollinated.
Nerve
— Same as a vein.
Neutral
— Spoken of a flower which has neither stamens or pistils.
Nigrescent
— Becoming black or blackish.
Nodding
— Hanging on a bent peduncle or pedicels.
Node
— The point along a stem which gives rise to leaves, branches, or inflorescences.
Nodose
— Knotty or knobby.
Nodulose
— Provided with little knots or knobs.
Nut
— A hard, indehiscent, one-seeded, fruit, typically with an outer shell.
Nutlet
— A small nut or achene, typically 1-seeded, usually lacking a specific outer shell.
O

Obconic
— Inversely conical.
Obcordate
— Referring to leaves or petals which are heart-shaped at the tip and tapering to a wedge-shaped base. [Plate 3]
Oblanceolate
— Several times longer than wide, but widest above the middle, long-tapering at the base.
Oblique
— Slanting, or unequal-sided. [Plate 5]
Oblong
— Several times longer than wide with nearly or quite parallel sides. [Plate 3]
Obovate
— Inversely ovate. [Plate 3]
Obovoid
— Having the form of an egg, but with the broad end at the tip.
Obsolete
Rudimentary; not evident.
Obtuse
Blunt or rounded. [Plate 5]
Ochroleucous
— Yellowish white.
Ocrea
— In the Polygonaceae, refers to the tubular sheathing stipules along the stem.
Ocreola
— In the Polygonaceae, a secondary ocrea, usually referring to those of the inflorescence.
Olivaceous
— Having an olive-green color.
Opaque
— Dull; neither shining nor translucent.
Opposite
— Arranged in pairs along an axis, not alternate. [Plate 2]
Orbicular
— Circular in outline. [Plate 3]
Osier
— A long, lithe stem.
Oval
— Broadly elliptical. [Plate 3]
Ovary
— That portion of the pistil which contains the ovules. [Plate 9]
Ovate
— Egg-shaped. [Plate 3]
Ovoid
— A solid with an ovate outline.
Ovule
— The body which, after fertilization, becomes the seed.
P

Palate
— A rounded projection of the lower lip of some irregular corollas, often closing the throat, as in Utricularia. [Plate 10]
Palea
— The uppermost of the two scales forming the floret in a grass spikelet (often obscure). [Plate 12]
Palmate
Radiately lobed or divided, the axes of the individual segments originating at a common point or nearly so. [Plate 2 and Plate 5]
Paludal
— Pertaining to marshes.
Pandurate
— Fiddle-shaped.
Panicle
— An inflorescence composed of two or more racemes or racemiform corymbs. [Plate 8]
Paniculate
— Bearing panicles
Paniculiform
Panicle shaped.
Pannate, Pannose
— With a tight, densely tangled tomentum; Appearing felt-like. [Plate 6]
Panne
— Typically, a moist interdunal depression, often scoured down to the water table, in calcareous sands on the lee sides of dunes near Lake Michigan -- the vegetation quite fen-like in composition.
Pannose
— See Pannte
Papilionaceous
— Butterfly-like; in the Fabaceae family particularly, having a corolla composed of a standard, keel, and two wing petals. [Plate 10]
Papilla
— A minute, nipple-shaped projection.
Papillate, Papillose
— Bearing papillae; warty or tuberculate. [Plate 6]
Pappus
— A modification of the calyx, usually in the Asteraceae family, such that the segments are manifest as a low crown, a ring of scales, or fine hairs. [Plate 12]
Papule
— A single wart or tubercle.
Parallel
— Running side-by-side, from base to tip. [Plate 5]
Parallel-veined
— A feature occurring largely in the Monocots, where, instead of a network, the observable veins are parallel to each other and the midrib, or nearly so.
Parasite
— A plant which grows on and derives nourishment from another living plant.
Parenchymatous
— Composed of thin-walled cells.
Patina
— A fine crust or film.
Peat
— Soil or substrate heavily invested with or even totally composed of partially decayed organic matter.
Pectinate
— Fringed or dissected in comb-like fashion.
Pedicel
— The stalk of a single flower in a cluster. [Plate 8]
Pedicellate
— Having a pedicel.
Peduncle
— Characteristically referring to the second internode below a flower, but generally applied to any primary stalk which supports a head, flower cluster, or occasionally a single flower. [Plate 8 and Plate 9]
Pedunculate
— Having a peduncle.
Pellucid
— Clear; transparent.
Peltate
— Leaf/petiole relationship in which the petiole attaches to the blade away from the blade margin. Also similar relationships between stigmas and styles, indusium attachments to the frond surface, etc. [Plate 5]
Pendulous
— Drooping.
Pepo
— The specialized fruit in the gourd family -- essentially a large berry but possessing a thick rind.
Perennial
— Pertaining to a plant which lives for more than two years.
Perfect
— Pertaining to flowers which contain both stamens and pistils.
Perfoliate
— A condition in which the stem appears to pass through the leaf. [Plate 5]
Perianth
— Pertaining to the floral series of sepals, petals, or both, spoken of collectively. [Plate 9]
Pericarp
— The wall of the matured ovary.
Perigynium
— Referring specifically to the often inflated sac which encloses the achene in the genus Carex. [Plate 12]
Perigynous
— With the perianth surrounding the ovary.
Persistent
— Remaining attached, especially after withering; not caducous.
Petal
— A segment of the corolla. [Plate 9 and Plate 10]
Petaloid
— Colored like, or resembling, a petal.
Petiolar, Petiolate
— Having a leafstalk.
Petiole
— A leafstalk. [Plate 2]
Petiolulate
— Having a leaflet stalk.
Petiolule
— The stalk of a leaflet. [Plate 2]
Phloem
— The conducting tissue of the vascular system that transports sugars and other compounds, primarily from the leaves, throughout the plant. Compare to xylem.
Phyllary
— An involucral bract in the Asteraceae family. [Plate 12]
Phyllodium
— A somewhat dilated leafstalk having the form of and serving as a leaf blade.
Pilose
Pubescent with soft hairs. [Plate 6]
Pinna
— One of the principal divisions in a pinnate or pinnately compound leaf or frond.
Pinnate
— Referring to a foliar structure which is compound or deeply divided, the principal divisions arranged along each side of a common axis. [Plate 2 and Plate 5]
Pinnatifid
— Incompletely pinnate, the clefts between segments not reaching the axis. [Plate 4]
Pinnatisect
Pinnately dissected.
Pinnule
— One of the principal divisions of a pinna.
Pistil
— That organ comprised of ovary, style (when present), and stigma. [Plate 9]
Pistillate
— Referring either to plants, inflorescences, or flowers which bear pistils but not stamens.
Pith
— The parenchymatous, often spongy or porous, central portions of stems and branchlets. [Plate 7]
Pitted
— Beset with depressions or pits.
Placenta
— The inside portion of the ovary which bears the ovules.
Plait
— Specifically, referring to the folded, often fringed, membrane between the corolla lobes in the genus Gentiana.
Plano-convex
— Similar to lenticular, but with one of the faces flat instead of convex.
Plicate
— Folded into plaits, usually lengthwise, thus similar to corrugated.
Plumose
— Beset with numerous, fine, pinnately arranged hairs; resembling a feather.
Pod
— A general term used with different fruit types, such as legume (pea pod), follicle (milkweed pod), or for certain seed-bearing capsules (iris pod).
Pollinium
— A coherent mass of pollen, such as in the Orchidaceae family and Asclepiadaceae family. Plural: pollinia.
Polygamous
— Typically referring to an individual plant which contains both perfect and imperfect flowers.
Polymorphic
— Having a number of various forms.
Pome
— A fleshy fruit (as in the apple), formed from an inferior ovary with several locules. [Plate 11]
Pore
— The small area which bursts open in some types of dehiscent capsules; also the opening in some anthers from which the pollen discharges.
Poricidal
Dehiscing by means of pores. [Plate 11]
Posterior
— Next to or close to the main axis; its opposite is anterior.
Prickle
— A sharp, usually slender, bristle or spine of the epidermis, though originating in the deeper cell layers. [Plate 7]
Primary
— Principal; first order.
Primocane
— In Rubus, the cane of the first year (usually lacking flowers).
Prismatic
— Of the shape of a prism -- angulate with flat sides.
Process
— A projection or outgrowth from some parent tissue.
Procumbent
— Trailing or reclining, but not rooting at the nodes. [Plate 1]
Prostrate
— Lying flat upon the substrate.
Proximate
— Near. The near end. Opposite meaning of distal.
Puberulent
— Minutely hairy. [Plate 6]
Pubescent
— Hairy.
Pulverulent
— Appearing powdery or mealy. [Plate 6]
Pulvinus
— A swelling or enlargement, typically in the axils of the branches in a grass inflorescence.
Punctate
— Dotted, particularly with dark or translucent dots or glands.
Puncticulate
— Minutely punctate.
Pungent
— Very sharp; acrid to the taste or smell.
Pustular
— Bearing blisters or pustules.
Pyramidal
— Broadest at the base, tapering apically; pyramid-shaped.
Pyrene
— The nutlet of a drupe, such as the seed and bony endocarp of a cherry.
Pyriform
— Pear-shaped.
Q

Quadrangular
— Four-angled.
R

Raceme
— A simple inflorescence in which the flowers are pedicellate and arranged singly along an elongate axis. [Plate 8]
Racemiform
— Resembling a raceme; or an adjective describing a raceme.
Racemose
— Having flowers in racemes.
Rachilla
— A secondary rachis. [Plate 12]
Rachis
— The principal axis of an inflorescence or compound leaf. [Plate 2]
Radially symmetrical
Actinomorphic; capable of being bisected into two or more similar planes. Same as regular. [Plate 9]
Radiate
— Spreading in all directions.
Ranked
— Ordered in a series, usually used with a number, such as two-ranked.
Ray
— A strap-shaped, ligulate, typically marginal, flower in the head of a composite inflorescence; also one of the principal branches of an umbellate or cymose inflorescence. [Plate 8 and [Plate 12]
Ray flower
— A strap-shaped, ligulate, typically marginal, flower in the head of a composite inflorescence. Also called ligulate flower. Compare to disk flower. [Plate 12]
Receptacle
— An enlarged or elongated end of a pedicel, peduncle, or scape on which some or all of the flower parts are borne, such as in the Asteraceae family or certain genera in the Rosaceae family. [Plate 9]
Recurved
— Directed backward or downward.
Reflexed
— Abruptly turned or bent downward.
Regular
Radially symmetrical, capable of being bisected into two or more similar planes. See actinomorphic.
Remotely
— Distantly; far apart.
Reniform
— Kidney-shaped. [Plate 3]
Repand
— Typically with a shallowly, unevenly lobed or sinuate margin.
Repent
Prostrate, creeping along the ground, typically applying to those plants which root at the nodes. [Plate 1]
Resinous
— Appearing to secrete or exude resin. [Plate 6]
Resupinate
— Literally oriented upside down.
Reticulate
— Forming a network of interconnecting veins. [Plate 5]
Retrorse
— Directed backward or downward. [Plate 6]
Retuse
— Notched slightly at an usually obtuse apex. [Plate 5]
Revolute
— Referring to margins which tend to roll back toward the lower surface of the midrib of a foliar structure. [Plate 4]
Rhizomatous
— Bearing rhizomes.
Rhizome
— An underground stem, typically horizontal. [Plate 11]
Rhombic
— A four-sided, typically obliquely angled, shape.
Rhomboidal
— A solid with a rhombic outline.
Riparian
— Growing along rivers; pertaining to rivers.
Rootstock
— Same as a rhizome; or the root system to which a scion is grafted.
Roseate
— Rose-colored.
Rosette
— Referring to a dense cluster of basal leaves, particularly with reference to winter annuals or biennials, or to scapose plants in which all the leaves are basal.
Rostellar
— Pertaining to the little beak, or rostellum, found in some orchid flowers such as Goodyera.
Rostrate
Beaked.
Rosulate
— Turning outward and downward, such as in the petals of a double rose.
Rotate
— Pertaining to corollas which are more or less flat and circular in general outline; wheel-like. [Plate 10]
Rudimentary
— Primitive; poorly developed.
Rufescent, Rufous
— Reddish-brown.
Rugose
— Wrinkled.
Rugulose
— Minutely rugose.
Runcinate
Coarsely and sharply cut or incised, the principal divisions typically directed backward, typified by the leaf of a dandelion. [Plate 3]
Runner
— A filiform or very slender stolon.
S

Sac
— A pouch or bladder.
Saccate
— Having a sac. [Plate 10]
Sagittate
— Shaped like an arrowhead, usually referring to leaves in which two basal lobes are directed backward and downward. [Plate 3 and Plate 5]
Saline
— Salty.
Salverform
— Having a slender tube abruptly expanded into a flat limb, like a Phlox blossom. [Plate 10]
Samara
— An indehiscent, winged fruit. [Plate 11]
Saprophyte
— A plant which grows on and derives nourishment from a dead plant or organic matter.
Sarmentose
— Producing slender, often, prostrate, runners or branches.
Scaberulous
— Minutely scabrous.
Scabrid
— Slightly roughened.
Scabridulous
— Minutely scabrous.
Scabrous
— Rough; harsh to the touch. [Plate 6]
Scale
— Generally a thin, sometimes scarious, much reduced, leaf, bract, or perianth part.
Scalloped
— Said of margins marked by a series of circular or arc-shaped teeth or projections.
Scape
— A leafless flowering stem arising directly from the ground; or, such a stem which possesses minute scale-like leaves much smaller than the basal leaves. [Plate 8]
Scapose
— Having or appearing to have a scape.
Scarious
— Typically, thin, dry, papery or membranous; usually not green.
Schizocarp
— A pericarp which splits into two to several one-seeded portions, termed mericarps or nutlets. [Plate 11]
Scurfy
— Bearing mealy or bran-like granules or scales. [Plate 6]
Secondary
— Once removed from primary, which see.
Secund
— Arranged or oriented along one side of an axis, typically referring to the flowers of an inflorescence. [Plate 8]
Segment
— One of the units of a leaf or perianth that is divided but not fully compound.
Senescent
— Growing old; aging.
Sepal
— A segment of the calyx. [Plate 9 and Plate 10]
Sepaloid
— Of the texture of, or resembling, a sepal.
Septate
— Divided by partitions.
Septicidal
— Referring to capsules which dehisce through the side walls or partitions, not opening directly into the locule. Plate 11
Septum
— Any kind of partition.
Sericeous
— With silky hairs. [Plate 6]
Serotinous
— Produced late in the season; late to open; having cones that remain closed long after the seeds are ripe.
Serrate
— With sharp, typically forward-pointing, teeth. [Plate 4]
Serrulate
— Minutely serrate. [Plate 4]
Sessile
— Without a stalk. [Plate 2]
Setaceous
Bristle-like.
Seriform
— Having the form of a bristle.
Setose
— Beset with bristles. [Plate 6]
Setulose
— Having minute bristles.
Sheath
— A tubular structure effected by the formation of leaf margins around the stem.
Shrub
— A woody plant, typically smaller than a tree, and typified as being branched from the base with two or more main stems. [Plate 1]
Silicle
— A short silique. [Plate 11]
Silique
— A specialized capsule in which a frame-like placenta or partition separates the two valves, most often occurring in the mustard family. [Plate 11]
Simple
— Not compound, a term usually applied to leaves; also, referring to a stem without branches or modifications. [Plate 2]
Sinuate
— Wavy. [Plate 4]
Sinus
— A cleft or dissection between two lobes.
Solitary
— Alone; single.
Sordid
— Appearing dirty; definitely not white.
Sorus
— Specifically, in ferns, the clusters or discrete aggregations of sporangia.
Spadix
— An inflorescence spike typified by a very fleshy axis. [Plate 8]
Spathe
— A foliaceous bract-like or sheathiform structure enclosing or partly enclosing an inflorescence. [Plate 8]
Spathiform
— Resembling a spathe.
Spatulate
— Strongly dilated or expanded toward the distal end; spoon-shaped. [Plate 3]
Species
— A group of like individuals, as white pine or bur oak.
Spicate
— Arranged in, or resembling, a spike.
Spiciform
Spike-like.
Spicule
— A hard point or protuberance, typically on a leaf margin.
Spike
— An unbranched inflorescence in which the flowers are sessile or subsessile along an elongate axis. [Plate 8 and Plate 12]
Spikelet
— A secondary or small spike; specifically, in the Poaceae family, the unit composed or one or two glumes subtending one to several sets of lemma and palea combinations. [Plate 12]
Spine
— A sharp, stiff, often slender, process; a thorn. [Plate 7]
Spinescent
— Ending in a spine, or bearing a spine.
Spinose
— Having spines; spiny.
Spinulose
— With minute spines or stiff bristles.
Spontaneous
— Growing wild, without cultivation.
Sporangium
Spore-producing structure.
Spore
— An asexual, one-loculed propagule of ferns and fern allies.
Sporocarp
— The fruit case of certain flowerless plants, containing sporangia or spores.
Sporophyll
— A foliar organ upon which sporangia are produced.
Spur
— An extended sac at the base of a corolla; a short branchlet with a very compact arrangement of leaf scars. [Plate 7 and Plate 10]
Squarrose
— Pertaining typically to perianth or involucral segments which bend outward or downward at the tip.
Stalk
— The stem of any organ, as the petiole, peduncle, pedicel, filament, or stipe.
Stamen
— Pollen-producing structure comprised of the anther and the filament. [Plate 9]
Staminate
— Referring either to plants, inflorescences, or flowers which bear stamens but not pistils.
Staminodium
— A sterile stamen, or any structure lacking an anther but which corresponds to a stamen.
Standard
— The upper, dilated or expanded, petal in a papilionaceous flower.
Stellate
— Star-shaped, usually in reference to hairs which are branched, forked or divided into two to several rays. [Plate 6]
Stem
— The main axis or principal shoot of a plant.
Sterile
— Incapable of reproducing sexually; also, referring to soil, very poor in nutrients.
Stigma
— That part of the pistil receptive to pollen. [Plate 9]
Stipe
— A small connecting stalk; sometimes a small stalk which elevates the pistil or flower above the receptacle or pedicel; also, the petiole of a fern frond or of Lemna.
Stipel
— An appendage of a leaflet analogous to a stipule.
Stipitate
— Stalked, as defined above under stipe.
Stipular
— Belonging to stipules.
Stipulate
— With stipules.
Stipule
— An appendage or bract situated at either side of a leaf axil. [Plate 2 and Plate 7]
Stipuliform
— Resembling a stipule.
Stolon
— A horizontal, prostrate, running branch or stem, often tending to root at the nodes.
Stoloniferous
— Having stolons. [Plate 1]
Stoma
— A minute orifice between two guard cells in a leaf epidermis, through which gaseous exchange is effected -- plural stomata.
Stramineous
— Tan or straw-colored.
Striate
— Beset with fine, longitudinal lines or grooves.
Strigillose
— Minutely strigose.
Strigose
Pubescent with appressed hairs. [Plate 6]
Strigulose
— Minutely strigose.
Strobile
— An inflorescence, often, but not always, indurated or woody, characterized by a series of imbricated scales; a cone.
Style
— A usually slender stalk connecting the stigma with the ovary. [Plate 9]
Stylopodium
— A disk-like expansion of the base of the style, with the term often meaning to include the style as well.
Sub-
— Prefix meaning nearly, almost, or less than.
Submersed
— Found under water.
Subtend
— Referring to any structure situated at the base of another structure.
Subterranean
— Below the ground.
Subulate
— Awl-shaped.
Subulus
— A small point or bristle.
Succulent
— Very fleshy and juicy.
Suckers
Vegetative shoots from a proliferating root system.
Suifruticose
— Nearly or slightly woody. Compare fruticose.
Sulcate
— Grooved or furrowed lengthwise.
Superior
— Referring to an organ which stands above or appears over or higher than another similar organ; or in reference to an ovary, free from the calyx. [Plate 9]
Supra-, super-
— Prefix meaning above, or upon, or more than. Opposite of infra-.
Supra-axillary
— Borne above the axil.
Suture
— A seam or union between partitions; a line of dehiscence as in a follicle or capsule.
Symmetrical
Regular as to the number of its parts and their shape.
Sympatric
— Occupying the same region.
Sympetalous
— With petals united, at least at the base.
Sympodial
— A determinate inflorescence that simulates an indeterminate inflorescence, as if a scorpioid cyme were straight rather than circinate; or when an alternate-leaved plant's branching pattern mimics an opposite-leaved plant, producing forked branching.
Syncarp
— A multiple fruit (usually fleshy), typified by the mulberry group.
Synecology
— Referring to the total ecology of a given plant community or community complex.
T

Taproot
— The primary, central, downward-growing root. [Plate 1]
Taxon
— A discrete taxonomic unit.
Teeth
— Sharp processes at the edges of tissues.
Tendril
— A slender, often ultimately coiled, foliar or branch-like organ which clings to a support. [Plate 7]
Tepal
— Used in reference to the sepals and petals (usually in the Monocots) which often resemble each other; in such instances either a given sepal or a given petal is termed a tepal. [Plate 10]
Terete
— Circular in cross section.
Terminal
— Positioned at the summit.
Terminus
— End.
Ternate
— Three-parted; with three principal divisions; also, occurring in threes. [Plate 2]
Terrestrial
— Referring to plants which live out their lives on land.
Testa
— Outer coat of a seed.
Tetragonal
— Four-angled.
Thorn
— A reduced, sharply pointed branch or modified leaf; or remnant that originates below the epidermis. About the same as a spine. [Plate 7]
Thyrse
— A cylindrical or ovoid, often compact, panicle. [Plate 8]
Thyrsiform
— Resembling a thyrse.
Thyrsoid
— Having the form of a thyrse.
Tomentose
— Densely pubescent with matted hairs. [Plate 6]
Tomentulose
— Finely tomentose.
Tomentum
— Closely matted or tangled hairs.
Toothed
— Bearing teeth.
Torulose
— Cylindrical, abruptly contracted at intervals, typically occurring in fruits, between the seeds.
Translucent
— Between opaque and transparent, thus allowing some light to get through.
Transverse
— Running or lying across something.
Tree
— A woody plant, typically higher than a shrub, and typified as being unbranched at the base and having a strong single trunk. [Plate 1]
Tri-
— A prefix meaning three; for example, trifoliolate refers to three leaflets.
Trichome
— A stiff, often multicellular, hair.
Trident
— With three segments or lobes, usually having a common origin.
Trifid
— Three-cleft.
Trigonous
— Three-sided.
Tripinnate
— Said of a leaf in which the blade is pinnately compound with each of the divisions then bipinnately compound. [Plate 2]
Tristigmatic
— Bearing three stigmas.
Truncate
— Ending abruptly, as if cut straight across. [Plate 5]
Tube
— Usually referring to the connate parts of either the calyx or the corolla.
Tuber
— A term generally referring to any thick, fleshy enlargement of a rhizome or stolon. [Plate 1]
Tubercle
— A small tuber-like, often indurated, process or protuberance.
Tuberculate
— Having tubercles. [Plate 6]
Tuberiferous
— Bearing tubers.
Tuberose
— Resembling a tuber.
Tuberous
— Having the character of a tuber; tuber-like in appearance. [Plate 1]
Tubular
Tube-like. [Plate 10]
Tufted
— Usually referring to the compact arrangement of the stem bases with respect to each other and their position in the soil; same as cespitose.
Tumid
— Swollen.
Turbinate
— Top-shaped; inversely conical.
Turgid
— Swollen, or tightly drawn; said of a membrane or covering expanded by pressure from within.
Twig
— The shoot of a woody plant representing the growth of the current season and terminated basally by the circumferential terminal bud-scar of the previous year. [Plate 7]
U

Ultimate
— Last; final.
Umbel
— An inflorescence in which the branches all radiate from a common point. [Plate 8]
Umbellate
— With umbels.
Umbellet
— A secondary umbel.
Umbelliform
— Resembling an umbel.
Umbilicate
— Indented, invaginated, or depressed near the center.
Uncinate
— Hooked or bent at the tip. [Plate 6]
Undulate
— With a sinuate or wavy surface or margin (up and down, not in and out).
Unisexual
— Of one sex, either staminate or pistillate only.
United
— Connected.
Unsymmetrical
Irregular as to the number of its parts, or their shape.
Urceolate
Urn-shaped. [Plate 10]
Urn-shaped
— Hollow and cylindrical or ovoid, and contracted at or below the mouth, like an urn; also known as urceolate.
Utricle
— A bladder-like, usually indehiscent, one-seeded fruit.
V

Valvate
— Opening by valves; meeting at the edges without overlapping.
Valve
— One of the segments into which a capsule dehisces, previously having been held together by union along a suture.
Variety
— An infraspecific taxon with a range or habitat relatively distinct from other taxa within a species.
Vascular
— Having veins or conducting vessels.
Vascular Bundle
— An aggregate or cluster of vessels. [Plate 7]
Vegetative
— Referring to plant parts that are not involved in sexual reproduction.
Vein
— A thread of fibro-vascular tissue in a leaf or other organ (which often branches). Same as nerve.
Veinlet
— A small vein.
Velutinous
Pubescent with velvety hairs. [Plate 6]
Venation
— The arrangement or nature of the veins.
Ventral
— Pertaining to the inner or anterior face of an organ; opposite of dorsal.
Versatile
— Attached at or near the middle and turning freely on its support, such as an anther.
Verticil
— A whorl. [Plate 8]
Verticillate
— Having verticils; that is, whorled or appearing so.
Vestigial
Rudimentary.
Villous
— With long, straight, soft hairs. [Plate 6]
Vine
— A plant which climbs or sprawls by means of twining or tendrils; also, a plant which trails or creeps extensively along the ground.
Virgate
— Slenderly straight and upright; wand-shaped.
Viscid
Glutinous; sticky; glandular.
Vivipary
— Germinating while still on the plant, as certain bulbs and transformations of floral tissues.
W

Warty
Coarsely papillose.
Whorl
— An arrangement of three or more organs at a single node. [Plate 2]
Wing
— In general, any thin, expanded portion of an organ; sometimes referring to the well developed, exaggerated decurrence of a leaf base; also, one of the two lateral petals of a papilionaceous flower.
Winter annual
— An annual which sets its rosette and flowers the following spring.
Wiry
— Said of a stem which is thin but stiff.
Woolly
— With long, soft, matted or tangled hairs.
X

Xeric
— A microclimatic term which refers to an area in which the soils are dry, containing very little, if any, moisture. Compare to mesic.
Xylem
— The conducting tissue of the vascular system that transports water, primarily from the roots, throughout the plant. Compare to phloem.
Y

Z

Zygomorphic
— Referring to a calyx or corolla which is bilaterally symmetrical, capable of being divided into two equal halves along one plane only. [Plate 9]

Contents of Plates

Plate 1:
Stem and Root Types.
Plate 2:
Leaf Composition, Parts, and Types.
Plate 3:
Leaf Shapes.
Plate 4:
Leaf Margins.
Plate 5:
Leaf Apices, Venation, and Bases.
Plate 6:
Surface Features.
Plate 7:
Stem and Leaf Parts, and Variations.
Plate 8:
Inflorescence Types.
Plate 9:
Floral Morphology.
Plate 10:
Corolla Types.
Plate 11:
Fruit Types.
Plate 12:
Sedges, Grasses, and Composites.

Information provided on this page applies to the Chicago Region and may not be relevant or complete for other regions.

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