Tuyamaella S. Hatt, a small genus represented by six species and two varieties, is distributed in Asiatic and oceanic region (Zhu & So, 2000a, 2001). Of these, one species and two varieties are endemic to their respective countries, viz. T. borneensis Tixier (Indonesia), T. molischii (Schiffn.) S. Hatt. var. brevistipa P.C. Wu & P.J. Lin (China), T. molischii (Schiffn.) S.Hatt. var. taiwanensis R.L. Zhu & M.L. So (Taiwan), T. hattorii Tixier is restricted to Vietnam and Laos, T. jackii (Steph.) Tixier is restricted to Vietnam and Kampuchea. The remaining three species show an extended range of distribution, viz. T. angulistipa (Steph.) R.M. Schust. & Kachroo (China, Indonesia, Malaysia, Vietnam, Kampuchea, Papua New Guinea), T. molischii (Schiffn.) S. Hatt. var. molischii (China, Japan, Malaysia, Vietnam) and T. serratistipa S. Hatt. (Indonesia, Papua New Guinea, Philippines, Malaysia, New Caledonia) (Tixier, 1973; Zhu & So, 1998, 2000a, b, 2001). The earlier record of T. angulistipa (= Pycnolejeunea angulistipa Steph.) from India by Chopra (1943) based on Stephani's (1914) report from India Orientalis (Perak) appears to be erroneous. Perhaps for this reason the genus does not find any mention in the recent review on Indian Lejeuneaceae in India (Asthana, 2007).
During the course of studies on the epiphyllous liverworts of Eastern Himalaya, the authors came across an interesting collection belonging to family Lejeuneaceae from West Siang district of Arunachal Pradesh which differed from all the known taxa of the family from India. Subsequent morpho-taxonomic studies on the plants followed by review of relevant literature (Tixier, 1973; Zhu & So, 1998, 2000a, b, 2001) revealed them to be Tuyamaella serratistipa S. Hatt., a species so far known from Indonesia, Papua New Guinea, Philippines, Malaysia and New Caledonia (Zhu & So, 1998, 2000b).