Section A. Structure and Specialized Characters:
VIII. Perianth and Hypanthium

A. Perianth Parts (Figure 6-5-2)

Anterior Lobes. The lobes away from axis, toward the subtending bract; abaxial lobes.

Anterior Ridges, Lines, Grooves. The lines, grooves, ridges in or on the dorsal side, abaxial, within the perianth.

Base. Bottom or lower portion.

Beard. A tuft, line or zone of trichomes.

Bristle. A stiff, strong trichome, as in the perianth of some members of the Cyperaceae.

Callosity. A thickened, raised area, which is usually hard; a callus.

Carina. Keel.

Claw. The long, narrow petiole-like base of a sepal or petal.

Corona. A crown; any outgrowth between the stamens and corolla which may be petaline or staminal in origin.

Dorsal Side. Back or abaxial side, or the lower side of a perianth part.

Faucal Area. The throat area.

Fringe. The modified margin of a petal, sepal, tepal or lip.

Hood. A cover-shaped perianth part, usually with a turned down margin.

Horn. A curved, pointed and hollow protuberance from the perianth.

Hypogynium. Perianth-like structure of bony scales subtending the ovary, as in Scleria and other members of the Cyperaceae.

Keel. The two united petals of a papilionaceous flower; any structure ridged like the bottom of a boat.

Ligule. The strap-shaped portion of a ray or ligulate corolla.

Lip or Labellum. Either of two variously shaped parts into which a corolla or calyx is divided, usually into an upper and lower lip, as in the Lamiaceae and Orchidaceae.

Limb. Expanded portion of corolla or calyx above the tube, throat or claw.

Lobe. Any, usually rounded, segment or part of the perianth.

Lodicule. Abortive perianth part in the Poaceae; hyaline scales at base of ovary in the Poaceae.

Palate. The raised area in the throat of a sympetalous corolla.

Pappus. Bristly or scaly calyx in the Asteraceae.

Petal. A corolla member or segment; a unit of the corolla.

Posterior Lobe. The lobe next to axis, away from the subtending bract; adaxial lobe.

Posterior Ridges, Lines, Grooves. The lines, grooves, ridges in or on the ventral side, adaxial, within the perianth.

Pouch or Sac. A bag-shaped structure.

Scale. Small, scarious to coriaceous flattened bodies within the perianth, as in the Cyperaceae and Asteraceae.

Sepal. A calyx member or segment; a unit of the calyx.

Spur. A tubular or pointed projection from the perianth.

Standard, Banner, or Vexillum. The upper, usually wide petal in a papilionaceous corolla.

Tepal. A member or segment of perianth in which the parts are not differentiated into distinct sepals and petals.

Throat. An open, expanded tube in the perianth.

Tube. The cylindrical part of the perianth.

Ventral Side. Top side or upper side of a perianth part.

Wing. Lateral petals, as in the Fabaceae; a flattened extension, appendage or projection from a perianth part.

B. Hypanthium Parts

Base. Bottom or lower portion of the hypanthium.

Limb. Free, flared portion of the hypanthium.

Neck. Narrowed portion of hypanthium, between the base and a flared limb.

Tube or Casing. Cylindrical part of the hypanthium.

C. Perianth Types
(Classification based primarily on fusion of parts)

Achlamydeous. Without perianth.

Apetalous. No petals or corolla.

Apopetalous or Choripetalous. With separate petals.

Aposepalous or Chorisepalous. With separate sepals.

Asepalous. No sepals or calyx.

Chlamydeous. With perianth.

Dichlamydeous. With perianth composed of distinct calyx and corolla.

Homochlamydeous. With perianth composed of similar parts, each part a tepal.

Sympetalous. With fused petals.

Synsepalous. With fused sepals.

D. Perianth and Hypanthium Structural Types (Figure 6-6-2)

Actinomorphic. With radially arranged perianth parts; ray-like figure.

Bilabiate. Two-lipped, with two unequal divisions.

Calcarate. Spurred.

Calceolate. Slipper-shaped, as in the corolla of Cypripedium.

Campanulate. Bell-shaped; with flaring tube about as broad as long and a flaring limb.

Carinate. Keeled.

Corniculate. Horned.

Coronate. Tubular or flaring perianth or staminal outgrowth; petaloid appendage.

Cruciate. Four separate petals in cross form.

Cucullate. Hooded.

Galeate. Helmet-shaped, as one sepal in Aconitum.

Gibbous. Inflated on one side near the base.

Globose. Round.

Infundibular. Funnel-shaped.

Ligulate or Ray. Strap-shaped.

Papilionaceous. With large posterior petal (banner or standard) two lateral petals (wings) and usually two connate lower petals (keel); as in the Fabaceae.

Personate. Two-lipped with the upper arched and the lower protruding into corolla throat.

Rotate. Wheel-shaped, with short tube and wide limb at right angles to tube.

Saccate. Pouch-like.

Salverform. Trumpet-shaped. With slender tube and limb nearly at right angles to tube.

Subglobose. Almost round or spherical.

Tubular. Cylindrical.

Unguiculate. Clawed.

Urceolate. Urn-shaped.

Ventricose. Inflated on one side near the middle.