The Genus Dinochloa (Gramineae-Bambusoideae) in Sabah

Abstract

Summary. Morphological characters of the culm, sheathing organs, branching, flowering branch and fruit of Dinochloa are discussed and their value in recognizing the genus is indicated. The description is based on 7 species occurring in Sabah (Borneo), 6 of them new: D. obclavata, D. sipitangensis, D. prunifera, D. trichogona, D. sublaevigata and D. scabrida. Relationships with other genera are discussed. A key to the species in Sabah is provided and illustrated description of each species given. The genus Dinochloa Biise has been characterized by its climbing habit, solid culms, very small one-flowered spikelets and relatively large fruit. Even though the genus was established in 1854 relatively little is known of its structure and natural history. The genus is found mainly in Malesia, extending to mainland Asia to the north. Because of this rather limited diagnosis, any bamboo without solid culms and small spikelets, even though climbing, has traditionally been placed elsewhere. The present paper is intended to give a broader view of the genus. The work is based on personal field observations and herbarium specimens. The description of the morphological characters was based on 7 distinct species from Sabah (East Malaysia) which were seen as living plants in the field during the period mid-August to mid-November 1979. Observations on D. scandens, the only species of Dinochloa native to Java (Indonesia), were also made during a limited time in 1976 from living plants cultivated in the Botanic Gardens, Bogor (Indonesia), and in forest in West Java. Some of the Philippine species have also been considered, but from type specimens only. Although only seven species of about 20 of the genus have been observed and studied closely, the description of morphological characters from these seven seems adequate to represent the range of diversity. The genus posseses several unusual characters which have never been recorded or discussed before in detail.