Botany · Ch 5 — Taxonomy and Systematic Botany
Family: Apocynaceae (milk weed family)
Family: Apocynaceae (milk weed family)
Apocynaceae (milk weed family, including Asclepiadaceae under APG) has about 345 genera and 4,675 species, mostly tropical/subtropical. Habit: tree (Alstonia), shrub (Nerium), herb (Catharanthus), woody twiner (Allamanda), or succulent (Adenium, Stapelia, Caralluma) - usually with milky sap in laticiferous vessels. Leaf: simple, usually opposite decussate (Calotropis), sometimes alternate (Thevetia) or whorled in threes (Nerium), exstipulate. Inflorescence: a panicle, dichasial cyme (often umbelliform in Asclepiadoids), or a raceme/axillary pair (Catharanthus). Flower: bracteate, pentamerous, hypogynous (rarely epigynous in Plumeria), actinomorphic but zygomorphic in Ceropegia. Calyx: 5 sepals, glandular appendages (squamellae) often present on the adaxial side. Corolla: 5 sympetalous petals, twisted or valvate, often forming corona-like outgrowths at the mouth of the tube. Androecium: 5 stamens, often epipetalous; in the Asclepiadoids the stamens fuse to the style forming a gynostegium, with pollen grains fused into a waxy pollinium linked to the adjacent anther's pollinium by a hair-like translator (retinacula), joined by a gland-like corpusculum. Gynoecium: bicarpellary, apically united, superior (rarely half-inferior in Plumeria), with a nectariferous disc at the base. Fruit: variable - berry (Landolphia), drupe (Cerbera), follicle (Asclepias) or capsule (Allamanda). …
| APG classification | Bentham and Hooker classification |
|---|---|
| Kingdom: Plantae | Kingdom: Plantae |
| Clade: Angiosperms | Class: Dicotyledonae |
| Clade: Eudicots | Sub-class: Gamopetalae |
| Clade: Asterids | Series: Bicarpellatae |
What this figure shows. A labelled botanical plate of Catharanthus roseus: the Habit of the erect flowering herb; the entire flower and its L.S. showing the hypocrateriform (twisted, salver-shaped) corolla tube, epipetalous stamens, style and hour-glass-shaped stigma; the apocarpous Gynoecium with its two scaly nectaries at the base of the ovary; a C.S. of the ovary; the mature fruit (a pair of elongated follicles) and seed; and the Floral diagram wi …
What this figure shows. A photograph of Calotropis gigantea (crown flower), a milky-latex shrub of family Apocynaceae (subfamily Asclepiadoideae), showing its clustered umbellate inflorescence of pale lilac-to-white reflexed corolla lobes surrounding a fleshy central corona, and its opposite, …
| Economic importance | Binomial | Useful part | Uses |
|---|---|---|---|
| Food plant | Carissa carandas | Fruits | Edible and used in pickles |
| Medicinal plant | Rauvolfia serpentina (Indian snake root / sarpagandha) | Dried roots | Alkaloid reserpine obtained from the roots can lower blood pressure and is used as a sedative for Schizophrenia |
| Medicinal plant | Catharanthus roseus | Aerial parts | Alkaloids vinblastine and vincristine are used to treat various human cancers |
| Dye yielding | Wrightia tinctoria | Seeds | An indigo-like dye is obtained from the seeds |