Billolivia tichii Lưu, Q.D.Nguyễn & N.L.VŨ, sp. nov.
Type :—VIETNAM. Lâm Đồng Province: Lạc Dương District, Đạ Chais Commune, Bidoup-Núi Bà National Park, W slope of Gia Rích mountain ridge, 18 November 2014, Lưu Hồng Trường, Nguyễn Quốc Đạt, Phạm Hữu Nhân, Nguyễn Thế Văn LUU, DAT, NHAN & VAN 1106 (holotype SGN!; isotypes SGN!, VNM!, DLU!, HNU!, HN!, VNMN!).
Billolivia tichii in the field, photo by Phạm Hữu Nhân
Distribution, habitat and phenology:—Found on humid soils along streams in montane moist evergreen closed forest at 1800-1900 m in elevation, Bidoup-Núi Bà National Park, Đà Lạt Plateau, Southern Annamites, Vietnam (Fig. 2). Flowering is seen in October to November.
Etymology:—Named after Nguyễn Thiện Tịch, a botanical lecturer at the University of Science in Hồ Chí Minh City, who first discovered the species and informed the authors about it as a possible new species.
Proposed IUCN conservation status:—Data Deficient (DD) (IUCN, 2001 & 2012). Given the species is only known from a single location of far less than 100 km2 that is currently fragmented by intensive fish farming and is likely to experience future expansion, it should be considered for listing in the Critically Endangered category, CR B1a&b(iii). However, as the forest type where it has been discovered crosses into the neighbouring national parks Phước Bình and Chư Yang Sin, Billolivia tichii possibly occurs there. To investigate if this species is distributed in these parks, additional surveys are needed. In addition, it will be necessary to evaluate and assess associated threats in order to make a sound conservation assessment.
Billolivia tichii in the lab, photo by Phạm Hữu Nhân
Notes:—Billolivia tichii is most similar morphologically to B. longipetiolata. Both species share several common characteristics, such as long pubescent petioles, pubescent stem, adaxially glabrous and abaxially sparsely pubescent leaves, leaf margins coarsely dentate and general shape and size of flowers. The violet tips to the corolla lobes are more similar, however, to those of B. violacea. A summary of the main characters distinguishing B. tichii from these two species is given in Table 1.
In the Đà Lạt Plateau two or three morphologically similar species of Billolivia are often seen growing in mixed populations along water courses; this holds for the case of B. tichii and B. longipetiolata. Our observations of the two species in situ over the last three years noted that the new species flowered from October to November while B. longipetiolata flowered from January to March. These non-overlapping flowering periods likely serve as an effective barrier preventing hybridisation.
Middleton, D.J., Atkins, H., Luu, H.T., Nishii, K. & Möller, M. (2014a) Billolivia, a new genus of Gesneriaceae from Vietnam with five new species. Phytotaxa 161 (4): 241-269. http://dx.doi.org/10.11646/phytotaxa.161.4.1 Middleton, D.J., Leong-Skornicková, J. & Nguyễn, Q.B. (2014b) A new species of Billolivia (Gesneriaceae) from Vietnam. Gardens’ Bulletin Singapore 66: 189-194.
IUCN (2001) IUCNRed List Categories and Criteria, Version 3.1. Gland and Cambridge: IUCN Species Survival Commission.
IUCN (2012) IUCN Red List Categories and Criteria: Version 3.1. Second edition. Gland and Cambridge: IUCN Species Survival Commission.