Thecanthes Wikstr.

Scientific Description

Family Thymelaeaceae.

Habit and leaf form. Herbs. Annual. Leaves basal and cauline. Mesophytic, or xerophytic. Leaves small to medium-sized; opposite; decussate; ‘herbaceous’, or leathery (sometimes ericoid); petiolate to subsessile; gland-dotted, or not gland-dotted; simple. Leaf blades entire; flat, or rolled; ovate, or obovate, or linear; pinnately veined; cross-venulate. Leaves without stipules; without a persistent basal meristem.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; condensed in racemes, or in heads. The terminal inflorescence unit racemose. Inflorescences terminal; peduncle expanded at apex into a funnel- shaped receptacle passing into involucral bracts; with involucral bracts (bracts 4, sessile); pseudanthial, or not pseudanthial. Flowers pedicellate. Pedicels flattened. Flowers bracteolate, or ebracteolate; regular. Floral receptacle markedly hollowed. Free hypanthium present; ovary-portion fusiform, style-portion longer and narrower. Hypogynous disk present, or absent; of separate members, or annular. Perianth sepaline (the corolla missing); 4; 1 -whorled. Calyx present; 4; 1 -whorled; polysepalous, or gamosepalous; blunt-lobed; imbricate; tubular; unequal but not bilabiate, or regular; white, or cream, or orange, or red, or pink, or purple; (tube) persistent. Corolla absent. Androecial members definite in number. Androecium 2. Androecial members free of the perianth; all equal; free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 2; attached on the rim of the hypanthium; all more or less similar in shape; reduced in number relative to the adjacent perianth; oppositisepalous; filantherous, or with sessile anthers. Anthers basifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Gynoecium 2 carpelled (1 aborting early). The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary unilocular; 1 locular (at maturity). Gynoecium stylate. Styles 1; apical, or lateral. Placentation parietal, or apical. Ovules in the single cavity 1; pendulous; epitropous; with ventral raphe; arillate (or carunculate); anatropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; indehiscent; achene-like, or a berry, or a drupe. Seeds endospermic, or non-endospermic. Cotyledons 2 (flat, expanded). Embryo straight.

Etymology. From the Greek for "envelope, sac" and "flower", presumably referring to the sack-like concave receptacle and attached bracts enclosing the flowers.