11. Pentaphragmataceae
五膜草科 wu mo cao ke
Authors: Deyuan Hong & Nicholas J. Turland
Herbs perennial, ± succulent, without latex. Rhizome elongate, robust, often ± woody. Leaves alternate; leaf blade large, asymmetric at base. Inflorescence an axillary cyme or cincinnus, solitary or 2 or 3 together; pedicels short or absent. Flowers bisexual, actinomorphic except calyx. Calyx tube campanulate or tubular; calyx lobes 5, persistent, often white, unequal in width, often 2 wider and other 3 narrower. Corolla adnate to calyx as far as distal part of calyx, 5-cleft for more than halfway, or nearly fully divided and appearing petaloid, often white. Stamens 5, alternate with corolla lobes, inserted at proximal part of corolla tube; filament glabrous; anther ovoid or long ellipsoid, introrse or almost lateral due to connective being developed and exserted higher than anther cells. Ovary inferior, 2-loculed; ovules numerous; stigma capitate or conic, entire. Fruit an indehiscent berry. Seeds numerous, minute, ovoid or ovoid-globose; testa obviously reticulate.
One genus and ca. 25 species: S China, Indonesia, Malaysia, Papua New Guinea, Philippines, Singapore, Thailand, Vietnam; two species (one endemic) in China.
Pentaphragmataceae and Campanulaceae are not immediately related, although both are in the Asterales. Pentaphragma has quite different flowers, with no hint of the secondary pollen presentation that occurs throughout Campanulaceae s.l. Thus the inflorescence is cymose, usually scorpioid; the sepals are petaloid, with two large ones and three small ones; the corolla is ± deeply lobed; there are nectariferous cavities between septa joining hypanthium to ovary (unique in flowering plants); and the anthers are extrorse (introrse in all Campanulaceae s.l.). In addition, there is no latex; the leaves are distichous, with leaf blades strongly asymmetric; and the endosperm is starchy, the latter condition being extremely uncommon in Campanulaceae s.l.
Hong De-yuan. 1983. Campanulaceae (Pentaphragmatoideae). In: Hong De-yuan, ed., Fl. Reipubl. Popularis Sin. 73(2): 174-176.
