18. Pandanaceae
露兜树科 lu dou shu ke
Authors: Kun Sun & Robert A. DeFilipps
Trees, shrubs, or woody lianas, terrestrial, evergreen, dioecious. Stems simple or often bifurcately branched, ringed with persistent annular leaf scars, often producing adventitious prop roots; aerial roots present or absent. Vegetative reproduction by suckers present or absent. Leaves simple, numerous, spirally arranged at apex of stems and branches, sessile, linear to lanceolate, leathery, often lustrous or glaucous, glabrous, keeled abaxially, parallel veined, with numerous horizontal secondary veins, base open-sheathed and amplexicaul, margin and midrib abaxially often spinulose, apex often long acuminate. Male inflorescences axillary and terminal, compound, bracteate, comprising several-branched racemes or panicles with crowded flowers on spicate ultimate branches; spathes often enlarged at apex, white or colored. Perianth absent. Male flowers sessile (pedicellate in Sararanga Hemsley), with pistillode sometimes present; stamens numerous, fasciculate, arising on rachises or spadix branches; filaments smooth (Pandanus) or papillose (Freycinetia), seemingly branched; anthers basifixed, 2-celled with 4 pollen sacs, dehiscing by longitudinal slits, connective often apiculate; pollen grains often spinulose. Female inflorescences terminal, solitary or in spikes, racemes, or capitula, short, bracteate, with crowded flowers, often pendulous in fruit. Female flowers with or without staminodes; pistils free or aggregated and appressed to adjacent pistils forming 1- to many-carpelled phalanges or clusters; ovary superior, 1- to several locular; ovules solitary to numerous, anatropous, placentation basal or parietal; style absent or very short; stigmas 1 or more, subsessile, glandular-papillose. Fruit a berry (Freycinetia) or drupe (Pandanus), when drupaceous a multiple structure (syncarp) composed of 2-20 woody, or basally fleshy or fibrous, cylindric to globose, connate, free or often crowded and clustered carpels, each cluster of carpels termed a "phalange," with mesocarp fibrous and often pithy or hollow above, fibrous and fleshy below; endocarp membranous or evanescent. Seeds 1 to numerous, minute, often fusiform; testa membranous (Pandanus) or crustose (Freycinetia); endosperm oily and fleshy, or starchy; strophiole originating from raphe sometimes present; embryo basal, minute; germination often epigeal.
Three genera and ca. 800 species: Old World tropics, several species introduced as economic or ornamental plants; two genera and seven species (one endemic, one introduced) in China.
See Stone (Blumea 16: 361-372. 1968; in J.-F. Leroy, Fl. Cambodge, Laos & Vietnam 20: 3-48. 1983; Bot. J. Linn. Soc. 97: 33-48. 1988).
Zhou Lingyun & Zhong Xiongwen. 1992. Pandanaceae. In: Sun Xiangzhong, ed., Fl. Reipubl. Popularis Sin. 8: 12-23.
