This paper revises the taxonomy of the species with ribbon-like roots of subfamily Podostemoideae and all species of sub family Tristichoideae in Thailand. The Tristichoideae comprise Dalzellia with four, all new, species (D. angustissima, D. kailarsenii, D. ranongensis, D. ubonensis); Cussetia (gen. nov.) with C. diversifolia, which is transferred from Dalzellia, together with C. carinata of Cambodia and Laos; and Terniopsis with three new species (T. brevipes, T. ramosa, T. ubonensis) and one new record for Thailand (T. malayana). Malaccotristicha is referable to the emended genus Terniopsis. The subfamily Podostemoideae includes Paracladopus chiangmaiensis (gen. & sp. nov.), Cladopus, with two species, of which C. fallax is a new record, and Polypleurum with nine species, seven of which and one variety are new (P. erectum, P. longicaule, P. longifolium, P. longistylosum, P. phuwuaense, P. rubroradicans, P. wallichii var. parvum, P. wongprasertii). A previous paper reported 13 species assigned to three genera of Podostemoideae with crustaceous roots. In total, nine genera and 34 species of Podostemaceae occur in Thailand, indicating that Thailand, like southern India and Sri Lanka, is a center of distribution for the family in Asia.
A new wild banana species, Musa barioensis Hakkinen, is described and illustrated, based on observed morphological characteristics in the field. Musa barioensis is abundant in the Bario Kelabit highland of Sarawak, East Malaysia and is the only Musa species that occurs in the area.
A new rheophytic grass, Arundinella riparia subsp. breviaristata Ibaragi, is described. It is similar to subsp. riparia in leaf anatomy, rhizome shape and habitat, but is different in awn length, spikelet length and distribution.
A new species of ginger, Etlingera palangkensis (Zingiberaceae) is described from Borneo. Though similar to E. nasuta, the new species is clearly distinguished by the color of flowers and shape of labellum.
Nervilia nipponica is critically endangered and poorly known throughout its range in Japan. In order to illuminate details of the species' life history, observations on the phenology and reproductive success of two large populations in Kochi Prefecture were made from 2003-2004. Patterns of emergence were comparable and individuals in both populations exhibited a highly synchronous phenology. The average individual flowering period lasted 12.3 and 11.0 days respectively at the two sites, and dehiscence of fruit capsules occurred 25.6 and 25.3 days after flowering. Only 34.2% and 28.4% of plants at the two sites successfully flowered, but rates of seed set were 38.2% and 52.4% despite the virtual absence of a nectar reward and the lack of pollen vectors, probably indicative of self-pollination. The failure of individuals marked in 2003 to re-emerge, as well as the appearance of unmarked individuals in 2004, suggests that the species has a capacity for dormancy and/or rapid propagation via the tuber. Evidence for the latter is provided by the excavation of 89 tubers from 58 individuals, representing an average rate of increase of 1.5 per individual per year. Recommendations are made for ongoing studies towards the development of a conservation strategy for the species.
The mitotic chromosome number, meiotic behavior and sporogenesis, allozyme variation, chloroplast DNA type, and morphological characteristics of two putative hybrids and their putative parents of Athyrium in Yakushima Island, southwestern Japan, were studied. Athyrium ×flavosorum is a sterile hypotetraploid (2n=159), and its putative parents A. arisanense and A. subrigescens are a sexually reproductive hypotetraploid (2n=158) and a sexual tetraploid (2n=160), respectively. Allozyme and morphological analyses showed that, A. ×flavosorum displayed intermediate characteristics between A. arisanense and A. subrigescens. The chloroplast DNA analysis showed that, A. arisanense and A. ×flavosorum had the same SSCP-PCR banding pattern. Athyrium ×purpurascens is a sterile tetraploid (2n=160), and its putative parents, A. subrigescens and A. kuratae, are sexually reproductive tetraploids (2n=160). Allozyme and morphological analyses revealed that A. ×purpurascens was an intermediate between A. subrigescens and A. kuratae; the chloroplast DNA of A. ×purpurascens was the same as that of A. kuratae. These data did not contradict the hypothesis that A. ×flavosorum originated from a hybridization between A. arisanense and A. subrigescens, whereas A. ×purpurascens originate from a hybridization between A. kuratae and A. subrigescens.
One-sided spiral arrangement of bracts is described in detail with comparison of distichous one in Boesenbergia (Zingiberaceae). Association among inflorescence structure, anther dehiscence patterns, and geographic distribution are discussed.