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Asclepiadaceae
| The Asclepiadaceae are mostly herbs and shrubs with white sap comprising about 250 genera and 2,000 species, many of which are lianous and some of which are cactuslike succulents with reduced leaves. The leaves are simple and nearly always opposite or whorled; minute stipules are present. The flowers are bisexual, nearly always actinomorphic, and usually include an elaborate crown or corona of nectariferous appendages between the corolla and sexual parts. The calyx consists of 5 distinct or basally connate sepals. The inner perianth is a 5-lobed sympetalous corolla. The androecium and gynoecium are nearly always adnate into a gynostegium with five highly modified stamens and a massive, 5-lobed stigma. The anthers usually produce paired sacs of pollen called pollinia that are transferred as a unit during pollination. The gynoecium consists of a single compound pistil of two nearly distinct carpels that are separate at the level of the ovaries and styles and are united only by a single massive stigma. The ovaries are distinct, nearly always superior, and each has a single locule with numerous marginal ovules. The fruit is a follicle. Seeds usually have a tuft of hairs at one end. |
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