Progress on the taxonomy of Digitaria Haller (Poaceae) in Thailand Boonchuang Boonsuk1*, Pranom Chantaranothai1 and Trevor R. Hodkinson2 1Applied Taxonomic Research Center, Department of Biology, Faculty of Science,
Khon Kaen University, Khon Kaen 40002, THAILAND
2Department of Botany, School of Natural Sciences, Trinity College Dublin, D2, IRELAND
Progress on the preparation of a taxonomic account of the genus Digitaria for Flora of Thailand is described. New taxonomic work on Digitaria is being based on field collection and herbarium specimens. Preliminary results have identified 24 indigenous species and one cultivated one, D. eriantha. All of them belong to subgenus Digitaria and can be subdivided in to six sections: Digitaria, Erianthae, Filiformis, Heteranthae, Ischaemum and Remotae. Three species, Digitaria cruciata, D. stricta var. glabrescens, and D. thyrsoidea are new records for Thailand. In addition, two taxa probably new species have been discovered. Digitaria is widespread in Thailand especially in open grassy areas, along roadsides, deciduous dipterocarp forests and lower montane scrubs. DNA sequencing of nuclear and plastid genes and anatomical techniques are being applied to advance systematic understanding of this diverse group of grasses.
KEY WORDS: crabgrass, Digitaria, Thailand