Pentastemona
Content
Description
Low juicy herbs with a short, unbranched, largely overground green rhizome with pale roots;
Leaves papyraceous when dry;
Inflorescences axillary, either short-peduncled simple racemes or long-peduncled compound racemes;
Flowers with one kind of perianth, 5-merous;
Stamens epitepalous;
Ovary inferior, one-celled, ovules numerous on three inward projecting longitudinally furrowed, parietal placentas;
Fruit berry-like, sharply longitudinally 10-ridged, the perianth persisting.
Seeds many, with a collar-like undulate aril covering about one third of the seed;
Distribution
Asia-Tropical, N and W Central Sumatra endemic
Malesia: the genus is locally endemic to N and W Central Sumatra, with 2 species.
Anatomy
Leaf epidermis anticlinal cell walls straight; stomatal complex tetracytic to cyclocytic; crystals present as abundant styloids and raphides, also as minute, irregularly shaped, solitary crystals. Minute druses have been found throughout the mesophyl. For comparison with Stemonaceae, see there (p. 400).