Tetsuo Koyama

Distribution and Evolution of C4 Syndrome in Rhynchospora(Rhynchosporeae-Cyperaceae)

In order to elucidate the evolution of C4 syndrome, the taxonomic relationships, leaf anatomy, and ecological and global distribution of C3 and C4 species in the genusRhynchospora were investigated. The anatomical observation for 181 species revealed that 26 C4 species occurred within theCapitatae group of the subgenusHaplostyleae, a natural group showing highly advanced morphological characteristics, together with several C3 species. In spite of there being rather few C4 species, they possessed two kinds of Kranz anatomical structure differing from each other in the location of Kranz cells. Some C3 species ofCapitatae showed radial arrangement in mesophyll cells surrounding vascular bundles, which is distinguished from typical non-Kranz anatomy. The C4 species extended their ecological ranges from wet habitats to dry savanna grasslands, while the C3 species showed the best development in wet habitats. The C3 species were widespread from tropical to temperate regions with partial range extension into subarctic regions of both hemispheres, showing conspicuously high concentration of species in the New World, but being absent from arid climatic regions. The C4 species were distributed mostly in tropics and subtropics, showing two separate distributional centers in South and Central America and in Tropical Asia and Australia. The range of C4 species was nearly completely included in the C3 range. In conclusion, it seems that inRhynchospora the C4 syndrome evolved relatively recently, and arose in at least two separate phylogenetic trends in the tropics and the subtropics, more probably in the Neotropics.

A new species of Torulinium (Cyperaceae) from the Bahama Islands

Torulinium correllii is described as new, and its phylogenetic significance with respect to the taxonomic relationship betweenTorulinium andMariscus discussed.

A taxonomic revision of the genus Heterosmilax (Smilacaceae)

Heterosmilax, a small southeastern Asiatic genus in the Smilacaceae, comprises 11 species in two sections, includingH. micrandra, which is described as new from Hainan, China. These taxa are taxonomically discussed, described, illustrated, and a key is provided to differentiate them.

Two new species and a new section of Cyperaceae from Brazil

Described as new are Lagenocarpus subaphyllus of the affinity ofL. triqueter, and Rhynchospora caesionux of sect.Spermodontes. Lageno carpus sect. Junciformes is proposed as new to accommodate the subaphyllous species of the genus with terminal panicles.

Cyperaceae of tropical America some new or critical species II

Described as new areHypolytrum pallidiceps, a clearcut species from Guyana,Oreobolus ecuadorensis, an ally ofO. obtusangulus from Ecuador, andScleria millespicula of the sectionOphryoscleria from Brazilian Amazonia.Oreobolus venezuelensis andScleria sprucei are newly added to the floras of Colombia and Venezuela respectively.

The genusFimbristylis (Cyperaceae) in ceylon

Thirty two species ofFimbristylis (Cyperaceae) thus far documented from Ceylon are taxonomically discussed with particular emphasis on the collections of Thwaites and Trimen. In addition to the synonymy and critical citation of specimens, a key is provided to differentiate these species.Fimbristylis tenera is newly added to the Ceylon flora. The new combinations proposed are:F. dichotoma ssp.glauca, F. fusca ssp.fulvescens, F. aestivalis ssp.major, andF. tenera ssp.oxylepis.

Studies in the cyperaceae of Thailand

Ten species ofCarex and one species ofKobresia from Thailand are taxonomically discussed, and some new range extensions into Thailand are noted. Described as new areCarex subinclinata andC. thailandica, both belonging to the sectionIndicae, andC. speciosa ssp.latifolia of the sectionRadicales. Two new combinations proposed areCarex helferi ssp.mapanifolia, andC. speciosa ssp.platyrhina.

Studies in the cyperaceae of Thailand II. Miscellaneous taxa of fimbristylideae, rhynchosporeae, scirpeae and sclerieae

Seven Thai species of Cyperaceae are taxonomically discussed, and references are made to two related Vietnamese species. Described as new areEleocharis macrorrhiza,Fimbristylis parvilenta,F. subtricephala (from Vietnam) andSchoenus smitinandii. New combinations made areBolboschoenus maritimus subsp.affinis. Diplacrum exiguum (from Vietnam),Rhynchospora hirticeps andSchoenoplectus annamicus.

Four new species of Smilax (Smilacaceae) from southeastern Asia

Described as new areSmilax biumbellata of the affinity ofS. nervomarginata,S. siamensis of the affinity of 5.perfoliata, and two others inSmilax sect.Macranthae:S. inversa andS. pachysandroides.Smilax inversa (characterized by strongly deflexed leaves and inflorescences on zigzag stems) andS. pachysandroides (with subsessile leaves on low simple stems) show no close resemblance to any previously known species of the section.

Further notes on the cyperaceae of ceylon

Six species of Cyperaceae from Cyelon are taxonomically discussed. Described as new isCarex taprobanensis, an ally ofC. stramentitia. New combinations made areBulbostylis barbata ssp.pulchella, Cyperus, conglomeratus ssp.pachyrrhizus, andMachaerina rubiginosa ssp.crassa.