Search

Myanmar is known for its high species richness of genus Gastrochilus; however, most of them lack proper information for taxonomic revision. During four years of field investigation in Myanmar, two new distributional records were encountered, namely, G. arunachalensis and G. corymbosus and one species, i.e. G. pechei was rediscovered after its original description. The three species were not easy to interpret from the available original descriptions and types due to severely shrunk or poorly preserved specimens. Therefore, we hereby present more detailed illustrations and updated descriptions for these species, based on freshly collected materials.

Zingiber natmataungense S.S.Zhou & R.Li (Zingiberaceae), a new species from Natma Taung National Park, Chin State, Myanmar, is described and illustrated. The new species is morphologically similar to Z. yunnanense, but differs by: leaf blade abaxially light green, glabrous, ligule sparsely pubescent, ca. 2–3 mm, bracts glabrous; calyx white 20–21 × 3.2–3.5 mm, glabrous, apex obviously 3-toothed; corolla tube white, ca. 3.9–4.1 cm, labellum lateral lobes, ca. 1.5–1.7 × 0.6–0.7 cm; stamen with sparse pubescent, filament white, glabrous, 1–2 mm; anther connective appendage yellowish proximally, purplish distally; ovary white, sparsely white pubescent, epigynous glands, ca. 6–7 mm long, tapered, apex whorled, yellow. This new species is also similar to Z. teres, but has a different flower colour.

Colocasia kachinensis S.S. Zhou & J.T. Yin, is described and illustrated as a new species of Araceae from Kachin, Mynamar. The morphological characters are compared to those of other Colocasia species. Colocasia kachinensis is closely related to C. menglaensis J.T Yin, H. Li & Z.F. Xu, 2004, but differs from in having an erect stem, no stolons, smaller size, a different pattern of surface bristle distribution and male flowers 1–4-androus with stamens connate in truncate synandrium.

A new species, Ophiorrhiza monsvictoriae S.S.Zhou & L.D.Duan, discovered at Natma Taung (Mt.Victoria) National Park, Chin State, Myanmar, is described and illustrated. The new species is morphologically similar to O. dulongensis, but differs from the latter by its stipules broadly triangular, 2–4 mm long, inflorescence axillary, 1-flowered, bracts lanceolate to subulate, 1–2 mm long, puberulous, calyx pilose, 1–2 mm long, lobes and tube equal length, corolla narrowly funnelform, 15 mm long, puberulous outside.

Coelogyne victoria-reginae, a new species of section Proliferae, from Natma Taung (Mt.Victoria) National Park, Chin State, Myanmar, is described and illustrated. It is morphologically similar to C. prolifera, but the clustered pseudobulbs, pure brownish- red flowers and column wing with irregular notches at the apex of the new species differ from the other species. A preliminary risk-of-extinction assessment shows that the new species is regarded as EN C2a[i] according to the IUCN Red List Categories and Criteria.

A remarkable new Premna species from Myanmar, P. grandipaniculata Y.H.Tan & Bo Li (Lamiaceae), is here described and illustrated. It differs from all known congeneric taxa by having huge complicated panicles which have tertiary branches formed by spike-like thyrses. In Premna, such a spike-like thyrse is found in P. bracteata and P. interrupta, but those species can be easily distinguished from P. grandipaniculata by their habit, indumentum, leaf size and inflorescence structure.

Trivalvaria rubra and Trivalvaria casseabriae, two new species of Annonaceae from Putao, Kachin State, Myanmar, are here described and illustrated. They are morphologically similar to T. costata and T. macrophylla. The major differences between them are outlined and discussed. A diagnostic key to the species of Trivalvaria is provided.

Hedychium putaoense Y.H. Tan & H.B. Ding, a new species of Zingiberaceae from Putao, Kachin state, Northern Myanmar, is described and illustrated. It is similar to H. densiflorum Wall. and H. longipedunculatum A.R.K. Sastry & D.M. Verma, but differs by its very small bract (4–6 × 2.5–3 mm vs. 18–19 × 5–5.5 mm and ca. 11 × 7 mm, respectively), semicircle and dark red bracteole, orange flower and broadly falcate to lanceolate lateral staminodes.

Aristolochia sinoburmanica Y.H.Tan & B.Yang, a new species of Aristolochiaceae from Putao, Kachin State, Myanmar, is described and illustrated. According to morphology (strongly curved perianth, 3-lobed limb, as well as 3-lobed gynostemium, anthers 6, adnate in 3 pairs to the base of gynostemium, opposite to the lobes), the species belongs to Aristolochia subgenus Siphisia. It is morphologically similar to A. faviogonzalezii, A. hainanensis, A. tonkinensis, A. saccata and A. xuanlienensis. The major differences between them are outlined and discussed. A detailed description, along with line drawings, photographs, habitat, distribution and conservation status, as well as a comparison to morphologically similar species, are also provided.

Dendrobium naungmungense, a new species from Naungmung, Kachin State, North Myanmar, is described and illustrated. It is morphologically similar to D. ciliatilabellum and D. vexabile, but the epichile is oblong with three long-ciliate laminae and the column wing has significant denticulation. A preliminary risk-of-extinction assessment shows that the new species should be regarded as Critically Endangered (CR) according to the IUCN Red List Categories and Criteria.

Coelogyne magnifica (Orchidaceae), a new species from Putao, Kachin State, Myanmar, is described and illustrated. It belongs to Coelogyne section Ocellatae Pfitzer & Kraenzl. and it is morphologically similar to Coelogyne corymbosa and C. taronensis, but can be distinguished from these species by its larger flowers, lanceolate sepals and petals, a narrowly ovate lip, which has two bright yellow patches surrounded by shiny brownish red and two fimbriate or erose-lacerate lateral keels on the lip. The major differences between these species are outlined and discussed.

Trivalvaria rubra and Trivalvaria casseabriae , two new species of Annonaceae from Putao, Kachin State, Myanmar, are here described and illustrated. They are morphologically similar to T. costata and T. macrophylla . The major differences between them are outlined and discussed. A diagnostic key to the species of Trivalvaria is provided.