Philippine Journal of Science
142:(3) 183-197, Special Issue
ISSN 0031 - 7683
Begonia Section Petermannia of Luzon Island, the Philippines
Rosario Rimorin Rivera Rubite
Department of Biology, College of Arts and Sciences
University of the Philippines Manila and
Philippine National Herbarium
National Museum, Manila, Philippines
ABSTRACT
Following a systematic study and recircumscription of Philippine Begonia section Baryandra, an initial revision of Begonia section Petermannia on Luzon Island is presented. Using field surveys in order to find as many species as possible, sixteen species are rediscovered in pristine forests of Luzon Island. Thirteen species are endemic to Luzon and ten are known from fewer than four localities. In the wild, many of these species were found to be represented by one population only. These results contribute not only to the future phylogenetic studies of the genus Begonia, but also to help define and refine conservation policies in the Philippines in order to offer better protection for narrowly endemic plant taxa.
INTRODUCTION
The family Begoniaceae is readily distinguished by having asymmetric leaves, petaloid tepals, unisexual flowers with bilaterally symmetrical staminate flowers and inferior winged ovaries. As currently recognized, it contains two genera, the species rich Begonia L., widely distributed
in tropical and subtropical regions of the world, and the monotypic Hillebrandia sandwicensis Oliver, endemic to the Hawaiian Islands (Kiew 2005, Tebbitt 2005).
Begonias are valued world-wide as ornamental plants. It is therefore surprising that the last comprehensive account of Philippine Begonia, recording 59 species (Merrill 1912) is now a century old, with no recent
revision (Rubite & Madulid 2009). A more up-to-date checklist (Hughes 2008) lists 104 Philippine species, with 103 of these being endemic. Globally, about 1,500 species have been named and there are undoubtedly many more to be discovered. . . . . . . . . . read more
