flower glossary

Parts of a flower

flower: The major parts of a flower are the pedicel, perianth, stamens, and pistils. [figure] [figure] Any of these parts may be missing or vanishingly small for a particular species or individual flower. [Jepson]

pedicel: The stalk of an individual flower. Compare to peduncle. [figure] [Jepson]
receptacle: The distal end of the pedicel (or sometimes the peduncle), where the flower parts (or head) are attached. See hypanthium. [figure] [Jepson]
perianth: The collective term for the calyx and corolla (with the calyx subtending the corolla). The term is usually used where the calyx and corolla are difficult to distinguish (except by position). [figure] [Jepson]
perianth part: A sepal or petal. The term is usually used where sepals and petals are difficult to distinguish. [figure] [Jepson]
tepal: A perianth part, especially where the perianth parts are ± entirely free.
hypanthium (hypanthia): The structure formed by the fused lower portions of the perianth. [figure] [Jepson]

Calyx

calyx (calyces): The collective term for all sepals of a flower. Protects the flower in bud. Usually green, but may match the color of the corolla or have some other color. [figure] [Jepson]
sepal: A free or fused member of the calyx. If partially fused, reference is usually made to a calyx lobe rather than a sepal as a whole. [figure] [Jepson]

Corolla

corolla: The collective term for all petals of a flower. Surrounds the flowers sexual parts. Usually bright colored. [figure] [Jepson, blue-eyed marys]
petal: A free or fused member of the corolla. If partially fused, reference is usually made to a free corolla lobe rather than a petal as a whole. [figure] [Jepson]

Pistil

pistil: A pollen-accepting (“female”) sexual part of a flower, each composed of an ovary, style, and stigma. [figure] [Jepson]
ovary: The usually wider base of the pistil that forms the seed or fruit when germinated. The hypanthium (perianth and stamens) may be attached to the top, the bottom, or somewhere along the sides of the ovary. [figure] [Jepson]
style: The tube that carries pollen from the stigma to the ovary. [figure] [Jepson]
stigma: The distal end of the pistil that captures pollen for germination. May be lobed. [figure] [Jepson]

Stamen

stamen: A pollen-producing (“male”) sexual part of a flower, each composed of a filament and an anther. [figure] [Jepson]
filament: The stalk that holds up an anther. [figure] [Jepson]
anther: The distal end of the stamen where pollen is produced. Usually has two lobes. [figure] [Jepson]
staminode: A sterile stamen with a modified appearance. [figure] [Jepson]

Parts of an inflorescence

inflorescence: A cluster of flowers from a common point or sharing a stalk that has only flowers on it. [Jepson]
bract: Small leaf-like structures (or analogue) at the base of an inflorescence. May be fused together or not. [Jepson]
bractlet: Smaller secondary bract within an inflorescence, or a smaller secondary bract on a pedicel that may not subtend any structure. [Jepson]
epicalyx (epicalyces): A whorl of bracts forming an extra calyx-like structure proximal/around the true calyx.
peduncle: The stalk of an inflorescence (or of a head in the sunflower family) or of an individual flower that is not part of an inflorescence. See also pedicel. [Jepson]
scape: A peduncle, particularly one that arises directly from ground level with no cauline leaves.

Inflorescence shapes

[figure] [figure]

For most flowering plants, these terms define the organization of flowers within an inflorescence and often define the order in which the flowers open. However, for some taxonomic groups, the definitions refer instead to the organization of inflorescence units relative to each other and may or may not define the order in which their flowers open. See the related glossary entries for the specific definition for each taxonomic group.

capitate: Arranged in a compact three-dimensional head.
catkin: A unisexual spike of flowers with ± no perianths. Usually pendulous, usually staminate, and usually wind-pollinated. [Jepson]
cyme: A branched inflorescence in which a flower at an axil opens before flowers on the subtending branches. [Jepson, sunflower glossary]
panicle: A branched inflorescence in which the flowers on the proximal branches open before those on the distal branches. (This can be thought of as a compound raceme.) [Jepson, grass glossary, sunflower glossary]
raceme: An unbranched inflorescence with pediceled flowers in which the flowers at the proximal end of the inflorescence open earlier than at the distal end. [Jepson, grass glossary, sunflower glossary]
spike: An unbranched inflorescence with sessile flowers in which the flowers at the proximal end of the inflorescence generally open earlier than at the distal end. [Jepson, grass glossary, sunflower glossary]
umbel: An inflorescence in which 3+ pedicels (for a simple umbel) or inflorescence branches (for a compound umbel) radiate from a common point with no continuation of the central axis. [Jepson, grass glossary, sunflower glossary]

Fruit

fruit: A seed-bearing body (or a joined aggregation of multiple bodies), developing from one or more ovaries and possibly other associated structures. [figure] [Jepson]
berry: Botanically, a fruit that developed from a single flower in which the ovary wall becomes the fleshy portion of the fruit. But in common usage (including the BAWG), it is simply a small, soft or juicy fruit or bite-sized collection of fruits from the same inflorescence. [Jepson]
pericarp: The outer, non-seed portion of a fruit. E.g. the fleshy part of a stone fruit.
beak: A projection from the distal end of a fruit. [Jepson, owl's clover]

Hair

bristle: A stiff, straight hair. [Jepson, sunflower glossary]
canescent: Densely covered with fine silvery white hairs. [Jepson]
ciliate: With generally straight hair along its margins. [Jepson]
glabrous: Without hair. [Jepson]
puberulent: Covered in very short, soft hairs. [Jepson]
strigose: Having stiff, straight, appressed hairs. [Jepson]
tomentose: Covered with matted, felt-like hairs. [Jepson]

Armament

These terms may occasionally be used loosely rather than following the strict definition. Many examples are given in this PDF.

prickle: Sharp-pointed projection not arising from a node. Often stiff. [Jepson]
spine: Sharp-pointed projection arising in place of a leaf, leaf part, or stipule. Usually stiff. [Jepson]
thorn: Sharp-pointed projection arising in place of a stem. Usually stiff. [Jepson]

Other flower terms

bud: An unopened flower, usually surrounded and protected by the sepals which are joined at the tip. [Jepson, plant glossary]
claw: A very narrow basal portion of a free petal or sepal. See limb. [figure] [Jepson]
cleistogamous: Self-pollinating without opening. Generally looks bud-like. [Jepson]
flower head: A dense inflorescence of ± sessile flowers. [sunflower glossary]
involucel: Secondary involucre within an inflorescence. [Jepson]
involucre: Collective term for a cluster of bracts. [Jepson, sunflower glossary]
limb: In a fused calyx or corolla, the spreading portion distal to the throat (or at least more widely expanded than the throat). [figure] In a free calyx or corolla, the expanded portion distal to the claw. [figure] [Jepson]
lip: The upper (adaxial) or lower (abaxial) lobe of a bilateral calyx or corolla that is divided into two lobes. [Jepson, blue-eyed marys, orchid glossary]
nectar: Sugary solution produced by a nectory for the purpose of attracting pollinators. [Jepson]
nectary: A structure that produces nectar. Usually at the inner base of a flower to attract pollinators past the anthers and stigmas, but may be elsewhere. [Jepson]
open: Not densely clustered, i.e. with parts that are spread out from each other. E.g. referring to a flower perianth that is maximally spread, e.g. not a bud. (For some flowers, this is not very spread at all.) [Jepson, plant glossary]
pappilate: Having small round protuberances on a surface.
pistillate: With fertile pistils but without stamens or without fertile stamens. See staminate. [Jepson, sunflower glossary]
salverform: With a slender tube and abruptly spreading limbs (e.g. “T” shaped). [Jepson]
spur: A hollow, backward-pointing projection from a sepal or petal. [Jepson, larkspur glossary]
staminate: With fertile stamens but without pistils or without fertile pistils. See pistillate. [Jepson, sunflower glossary]
throat: In a fused calyx or corolla, the expanded portion between the tube and the limb. [figure] [Jepson]
tube: In a fused calyx or corolla, the ± cylindric portion proximal to the throat. [figure] [Jepson]
valve: One part of a pericarp when the parts split by dehiscence. [Jepson]