Glossary for Asteraceae

For terms not listed here, see the Plant Glossary.

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.

Head

— 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.