A guide to collecting Pandanaceae (Pandanus Freycinetia, and Sararanga)

The family Pandanaceae is paleotropical and consists of three genera, Pandanus L. ex Stickm. with the most species (over 600) and the widest distribution, from W. Africa eastward throughout the tropical areas to the Pacific Islands; Freycinetia, with about 180 species and the next largest distribution, from Ceylon (but not India, except the Andaman and Nicobar Islands) eastward through the Malesian area into the Pacific and New Zealand; and Sararanga, a restricted small genus of two species, one in the Philippines and the other in New Guinea and the Solomon Islands. All species of Freycinetia are woody lianas; among these there occur some relatively large plants, with stems reaching perhaps 6-7 cm diameter and leaves of perhaps 150 cm length and a width of perhaps 10 cm; but most species are rather smaller and some are really quite small plants, the extreme perhaps being Freycinetia elegantula with leaves only 2-3 cm long. Both species of Sararanga are arboreous, branched, with rather massive leaves 200 cm long or more, and erect trunks. They have, unlike all other pandans, compound paniculate inflorescences that are pendulous and may be well over 100 cm long. The genus is readily recognized by its quadrifarious spiral phyllotaxy, and concomitant squaresection inflorescence rachises. The flowers and fruits are also unique in the family, the latter being irregularly globular many-seeded berries. The true pandans, Pandanus species, have a rather wide range of form and size, with tall arboreous plants such as Pandanus antaresensis of New Guinea, which may reach 33 m height and have massive proproots 10 m long and 20 cm thick, at one extreme, and diminutive shrubs such as Pandanus herbaceus, P. toei, or P. unguiculatus, which have short slender stems reaching at most 2 m height, and 2-3 cm or less in diameter (and in examples such as P. toei, are cespitose with little stem development) at the other extreme. Besides these examples, pandans have developed into epiphytic shrubs, some with a pseudo-lianous type of growth, others cespitose and "stemless" and most of these are small shrubs, although one species (P. epiphyticus) is, apart from its reduced stem, quite massive. The family is important in several regions wherein it has developed a high degree of endemism and contributes to the fundamental structure and physiognomy of the vegetation. In other regions its presence is limited to coastal areas. Only in the Philippines, New Guinea, and the Solomon Islands can all three genera be found occurring together. Outlying posts of the family include New Zealand, which has only Freycinetia, and only one species; and Sao Thom6 Island (off Angola, W. Africa), where one species of Pandanus occurs. Central areas of endemism are Madagascar, which has only the genus Pandanus but about 100 endemic species; Thailand, which has both Freycinetia (but only two or three species) and Pandanus, the latter with perhaps over two dozen species; Malaya, with eight species of Freycinetia and about fifty of Pandanus; Borneo, with two dozen species of Freycinetia and more than fifty of Pandanus; the Philippine archipelago, with about the same numbers of both genera as Borneo; New Guinea, with probably about 60 species of Freycinetia and 70 or more of Pandanus; the Solomon Islands, with about 23 species of Freycinetia and 28 species of Pandanus; and New Caledonia, with about 14 species of Freycinetia and 21 species of Pandanus. Some important secondary centers include Australia, especially Queensland, with only four species of Freycinetia but a somewhat richer Pandanusflora (possibly 15-20 species); Fiji; Mauritius; the Seychelles; Burma and the Himalayan foothills; Sumatra; and East Africa. Besides these, several small regions have one or a few local endemic species, usually of Pandanus to the exclusion of the other genera; examples are Lord Howe Island, Christmas Island (Indian Ocean), Hainan, etc.