Coelogyne putaoensis, a new species of section Ocellatae from Putao, Kachin State, Myanmar, is described and illustrated. It is morphologically similar to C. taronensis and C. weixiensis, presumably its nearest relatives. An identification key and colour photographs are provided. A preliminary risk-of-extinction assessment according to the IUCN Red List categories and criteria is given for the new species.

Arethuseae, Kachin, key, montane forest, section Ocellatae, taxonomy

Coelogyne Lindl. (Lindley 1821) (Orchidaceae, Epidendroideae, Arethuseae) is a genus of about 200 species, distributed from South and Southeast Asia into the Pacific as far east as Fiji and Samoa (Clayton 2002, Chen et al. 2009, George and George 2011, Gravendeel 2005). Around 45 species of Coelogyne have been recorded from Myanmar (Kress et al. 2003; Kurzweil and Lwin 2014). During fieldwork in Putao, Kachin State, Northern Myanmar, in June 2016, the first authors discovered a new species of Coelogyne, which is described below. The new species belongs to Coelogyne section Ocellatae Pfitzer & Kraenzl. (Pfitzer and Kraenzl. 1907).

All measurements of the three species here discussed, i.e., Coelogyne putaoensis, C. taronensis Handel-Mazzetti and C. weixiensis X.H. Jin, were taken from dried herbarium specimens and field notes. In the description, length and width are represented as length × width. About twenty living plants and three dried specimens of the new species and 10 specimens each of C. taronensis and C. weixiensis, including types or photos of types of all taxa, were examined.

Coelogyne taronensis, C. weixiensis and C. putaoensis are similar, both in vegetative morphology and in the size and shape of the flowers, and all come from the same general region, northern Myanmar and adjacent parts of China. There can be little doubt that they are closely related. They are readily distinguished on the basis of their colour differences, as indicated in the key and photos. Coelogyne weixiensis (Figure 4) and C. taronensis (Figure 5) are especially similar morphologically. They are listed as synonyms by George and George (2011). At present, too little is known about the variability of C. taronensis to make any assessment with confidence. Both taxa appear to be rare and local (C. weixiensis: China, Yunnan, Bilou Snow Mountains near Weixi; C. taronensis: China, Yunnan, Taron (=Dulong) Valley). Coelogyne putaoensis differs from the two others not only in having almost solid brown flowers, but also in the papillose margins of the keels on the lip, and in the median keel extending onto the mid-lobe. Altitudinal range and habitat are comparable for the three species: C. putaoensis was collected at 2500–3100 m, C. taronensis at 2400–3500 m, and C. weixiensis at 2600–3000 m elevation (Jin 2005). All three occur as epiphytes in montane forest. At least two of the three species (C. taronensis and C. weixiensis) are of high conservation interest, and habitat protection seems urgently needed for these. As far as we can ascertain, only C. weixiensis is currently in cultivation, having recently received a Botanical Certificate of the Royal Horticultural Society in the UK (as C. taronensis).

Figure 4. 

Close-up of flower of Coelogyne weixiensis. Photo by X.H. Jin.

Figure 5. 

Close-up of flower of Coelogyne taronensis. Photo by X.H. Jin.

Special thanks are due to Vincent Droissart for the critical reading and editing of the manuscript. This research was supported by grants from the Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (Grant No. Y4ZK111B01) and the National Natural Science Foundation of China (Grant Nos. 31670194, 31110103911). We also thank Yunxi Zhu for the excellent illustration.