Glossary for Asteraceae

For terms not listed here, see the Plant Glossary.

Line drawings of plant features.
Achene
— A hard, one-seeded, indehiscent nutlet with a tight pericarp. An example is the sunflower seed in the shell (pericarp).
Biseriate
— Having two series, or rows, of parts; having two rows or sets of phyllaries (bracts) on the involucre.
Claw
— The narrowed base of the corolla of a ray flower.
Crown
— In the Asteraceae family, scales or awns at the summit of an achene.
Disk or disc
— The central portion of a capitate inflorescence, or the receptacle of such an inflorescence.
Disk flowers
— The central, tubular flowers of the head. Compare ray flower.
Floret
— A single small flower, usually a member of a cluster, such as a head; see disk flower and ray flower.
— A dense, compact cluster of mostly sessile flowers, used to describe the inflorescence in the Asteraceae family.
Imbricate
— Having phyllaries (bracts) on the involucre that overlap each other like roof shingles.
Inflorescence
— The discrete flowering portion or portions of a plant; a flower cluster.
Involucre
— A whorl or imbricated series of bracts, often appearing somewhat calyx-like, typically subtending the head.
Ligulate
— Bearing a ligule.
Ligule
— The dilated or flattened, spreading limb of the composite ray flower.
Limb
— The expanded portion of a corolla above the throat; the expanded portion of any petal.
Pappus
— A modification of the calyx, usually in the Asteraceae family, such that the segments appear as a low crown, a ring of scales, or fine hairs.
Peduncle
— The stalk which supports a head.
Phyllary
— A bract of the involucre.
Ray
— A strap-shaped, ligulate, typically marginal, flower in the head of a composite inflorescence.
Ray flower
— A strap-shaped, ligulate, typically marginal, flower in the head of a composite inflorescence. Also called ligulate flower. Compare to disk flower.
Receptacle
— An enlarged or elongated base of a head on which the flowers are borne.
Staminal tube
— The stamens of a composite flower united into a ring.
Uniseriate
— Having only one series, or row, of parts; having only one row of phyllaries (bracts) on the involucre.

Family Glossaries

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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