ASCLEPIADACEAE
NB Asclepiadaceae is treated in APG IV as subfamily Asclepiadoideae in the Apocynaceae. The description below is for the Asclepiadoideae. For all other information see Apocynaceae.
Morphological description
Sometimes milky sap, climbing or epiphytic; exstipulate. Leafless (Sarcostemma).
Leaves
Leaves decussate, simple, entire, with a tuft of trichomes at base of leaf blade. Sometimes epiphyte with scale-like leaves (Absolmsia). Rheophytic shrub (Dorystephania); large shrub with white felty leaves (Calotropis); leaves transformed to pitchers (some Dischidia); pseudostipulae (Cynanchum).
Inflorescence
Ultimate branch of inflorescence an umbel, inflorescence usually terminal.
Flowers
Flowers small, corolla tube short with appendages forming a corona, stamens 5 united with style to form a gynostegium pollen in waxy masses (pollinia); ovary superior. Sometimes corolla tube long, curved (Ceropegia).
Fruits
Fruit apocarpous, 2-locular, many-seeded. fruit with many ridges (Myriopteron).
Seeds
Seeds hairy.
Different from: Apocynaceae s.s.: mostly woody, no trichomes, no gynostegium, no corona, corolla usually large, pollen free.
Distribution: The subfamily widespread. In Malesia c. 50 genera in rain forest as well as in mangrove, monsoon and secondary forest. - Dischidia (Indo-Australia), lowland and montane rain forest; - Hoya (Indo-Australia), mostly lowland rain forest; - Marsdenia (pantropical), lowland rain forest, secondary forest.
Notes: Many species are wind dispersed. - Ornamental plants: Asclepias*, Dischidia, Hoya. - Medicinal: Calotropis.
Literature: C.A. Backer & R.C. Bakhuizen van den Brink, Fl. Java 2 (1965) 244- 274.
Spot characters (Van Balgooy): Asclepias 103 - Asterostemma 95 - Atherandra 103 - Calotropis 103 - Ceropegia 103 - Cryptolepis 103 - Cryptostegia 103 - Cynanchum 32, 95, 103 - Dischidia 9, 103 - Dregea 99, 103 - Finlaysonia 99, 103 - Genianthus 103 - Gomphocarpus 95 - Gymnanthera 103 - Gymnema 103 - Heterostemma 103; H. cuspidatum 15 - Hoya 9, 76, 103 - Ischnostemma 103 - Marsdenia 98, 103 - Microstemma 103 - Myriopteron 32, 98 - Phyllanthera 103 - Physostelma 103 - Raphistemma 103 - Sarcostemma 8, 103 - Secamone 103; S. elliptica 15 - Stephanotis 103 - Streptocaulon 103 - Telosma 103 - Toxocarpus 103 - Tylophora 102, 103; T. cissoides 23.
Illustrations: Fig. 22. Dischidia subulata Warb. subsp. angustata Rintz (Asclepiadaceae). Habit. Reproduced from Blumea 26 (1980) 116, fig. 14., Fig. 23. Finlaysonia obovata Wall. (Asclepiadaceae). Reproduced from M.R. Henderson, Malayan wild flowers, Dicotyledons (1949/51, repr. 1974) 289. With kind permission of the Malaysian Nature Society. Fig. 24. Hoya multiflora Blume (Asclepiadaceae). Branch and fruit. Reproduced from Malayan Nature Journal 30 (1978) 494, fig. 12a, b. With kind permission of the Malaysian Nature Society. Fig. 25. Tylophora villosa Blume (Asclepiadaceae). Reproduced from C.A. Backer, Weed Flora of Javanese Sugar-cane fields, Atlas pt 16 (1973) t. 482.