A Synopsis of the Old World Species of Trichospermum Blume (Tiliaceae)

Summary

The genus Trichospermum Blume as accepted here includes not only the groups formerly separated as Belotia and Halconia, but also Althoffia K. Schum. It is predominantly a Malesian genus, distributed from the Malay Peninsula to the Solomon Islands, the Santa Cruz Islands, Fiji and Samoa, the number of species being greatest in New Guinea and adjacent islands; there are at least three species in tropical America. The thick fibrous bark is much used for making rope and cord. The Old World species of Trichospermum, sensu lato, number thirty-six, of which sixteen (T. arachnoideum, buruensis, fauroensis, fletcheri, fosbergii, gracile, graciliflorum, grewioides, helotrichum, incaniopsis, ovatum, rhamnifolius, smithii, stellato-pilosum, subdehiscens and talaudensis) are described here for the first time; Althoffia ledermannii is renamed T. burretii; the species T. kajewskii is reduced to synonymy of T. psilocladum. Two new combinations are proposed: T. pleiostigma (F.v.M.) and T. tripyxis (K. Schum.).

Burret's sub-division of Trichospermum is neither accepted nor replaced as the species show a reticulate relationship. The key and the main specific differences are based on the trichomes of the lower surface of the leaf.