The genus Plagiochasma (Aytoniaceae, Marchantiopsida) in Thailand

The genus Plagiochasma Lehm. et Lindenb. in Thailand is reviewed, based on herbarium specimens and especially on recently collections. The genus is reported for the first time from Thailand. Two species are recognized, namely P. appendiculatum Lehm. et Lindenb. and P. cordatum Lehm. et Lindenb. Descriptions, illustrations, and a key to species are provided.