Glossary table of contents

sunflower glossary

A single flower head in the sunflower family is actually a tight inflorescence of many flowers, often with separate shapes for the center disk flowers and outer ray flowers.

awn: Terminal bristle. [Jepson]
bristle: A stiff, hairlike tip of a pappus element. [Jepson, flower glossary]
disk: The collective term for all disk flowers in a head. [Jepson]
disk flower: A flower in the central portion of a head in the sunflower family. Usually radial and 5-lobed, usually bisexual but sometimes staminate. Often surrounded by ray flowers. [Jepson]
head: A tight inflorescence in the sunflower family which appears from a distance to be a single flower. [Jepson, flower glossary]
involucre: The green base of a flower head in the sunflower family. [Jepson, flower glossary]
ligule: A ray-like flower that is clustered only with other ligules in a liguliflorous head. Each ligule is tipped with 5 short lobes. [Jepson]
palea (paleae): A scale-like bract for an individual flower in some genera. [Jepson]
pappus: A modified calyx composed of some combination of scales, awns, and/or bristles. In some species, the pappus forms a parachute for seed dispersal. [Jepson]
pappus element: A modified sepal; one part among similar parts that make up the pappus.
phyllary: A bract of the flower head in the sunflower family. A member of the involucre. [Jepson]
ray: A flower in the outer portion of a head in the sunflower family. Flat and uni-directional, not radial. May be distally lobed. Usually pistillate, but sometimes sterile. The rays form a ring around the central disk. [Jepson, plant glossary]
scale: Flat, membranous element of a pappus. [Jepson, plant glossary]

Head shapes

discoid head: Head composed exclusively of disk flowers. [Jepson]
radiate head: Head composed of both disk flowers and ray flowers, e.g. a daisy. [Jepson]
liguliflorous head: Head composed only of ligulate flowers, e.g. a dandelion. [Jepson]

Inflorescence shapes

Within the sunflower family, these terms describe the organization of multiple heads in a larger inflorescence. For most of these terms, the order of development among heads is not defined.

cyme: A branched inflorescence in which a head at an axil develops before heads on the subtending branches. [Jepson, flower glossary]
panicle: An inflorescence in which at least some heads are attached to inflorescence branches rather than the central axis. [Jepson, flower glossary]
raceme: An inflorescence with stalked heads attached directly to the inflorescence axis (not to branches). [Jepson, flower glossary]
spike: An inflorescence with sessile heads attached directly to the inflorescence axis (not to branches). [Jepson, flower glossary]
umbel: An inflorescence in which 3+ stalked heads radiate from a common point with no continuation of the central axis. [Jepson, flower glossary]

Sexual capability

staminate flower: A staminate disk flower.
pistillate flower: A pistillate ray flower.