Two new species of Oreocharis (Gesneriaceae) from Fan Si Pan, the highest mountain in Vietnam Chen, Wen Hong Nguyen, Quang Hieu Chen, Run Zheng Nguyen, Tien Hiep Nguyen, Sinh Khang Nguyen, Van Tap Moeller, Michael Middleton, David J. Shui, Yu-Min PhytoKeys 2018 2018-01-29 94 95 106 7553V 0E21FD6C-F75D-5F54-A92C-1776769B9F8E W. H. Chen, Q. H. Nguyen & Y. M. Shui W. H. Chen, Q. H. Nguyen & Y. M. Shui 2018 Magnoliopsida Gesneriaceae Oreocharis treatment-meta Plantae Oreocharis grandiflora Lamiales 1 96 Tracheophyta species grandiflora sp. nov.  Diagnosis. This new species is similar to  O. flavidain the orange colour of the corolla, but differs from the latter by its much larger corolla (3.3-3.6 cm long vs. 1.5-1.7 cm), the shape of the corolla tube (infundibuliform vs. campanulate) and the reniform anthers which are coherent in two pairs (vs. horseshoe-shaped and not coherent). The two species further differ by the narrowly oblong or elliptic leaf blades in the new taxon (vs. ovate-elliptic to broadly ovate), cuneate leaf base (vs. cordate to rounded), the glandular villous indumentum on the outer surface of the calyx lobes (vs. eglandular villous).   Type.   VIETNAM. Lao Cai, Sa Pa distr., Ta Phin cave, in secondary forests, on cliffs nearby waterfalls, 22°20'43.66"N, 103°46'30.48"E,  2017 melevation, 30 October 2012, type specimen from a plant cultivated in an experimental greenhouse at Kunming Botanic Garden, 7 September 2013,  Y.M. Shuiet al. B2013-550( holotype, KUN!; isotype: Herbariumof the Centrefor Plant Conservation, Vietnam Union of Scienceand Technology Associations, Hanoi!). Perennial herbs. Leaves in basal rosette. Petiole 2.2-2.6 cmlong, with dense white glandular hairs; leaf blade coriaceous, narrowly oblong or elliptic, 4-6 x 1.8-3.5 cm, adaxially and abaxially covered by white glandular hairs, more densely on veins, base narrowly cuneate, apex acute, margin crenate; lateral veins 4-5 on each side of the midrib, adaxially depressed, abaxially prominent. Inflorescences axillary, 1-4-flowered. Peduncles 6-12 cmlong, with white glandular hairs; bracts 2, lanceolate, 5.6-6 x 1.1-1.2 mm, abaxially covered by white glandular hairs. Pedicel 1.5-1.8 cmlong. Calyx 5-lobed from base, lobes equal, linear-lanceolate, 7-8 x 1.1-1.2 mm, entire, adaxially glabrous, abaxially with white glandular hairs. Corolla deep orange, slightly bilabiate, 3.3-3.6 cmlong, inside pubescent, outside with white glandular short hairs; tube infundibuliform, 2-2.2 cmlong, 2.7-3 mmin diam. at base and 8-9 mmin diam. at throat; adaxial lip 2-lobed, lobes suborbicular, 8.5-9 x 11-12 mm, apex obtuse; abaxial lip 3-lobed, lobes suborbicular, slightly equal, 13-14 x 8-9 mm, apex more or less rounded. Stamens 4, anthers coherent in two pairs, filaments adnate to base of corolla tube, adaxial stamens 2-2.2 cmlong, abaxial stamens 2.6-2.8 cmlong; filaments with white glandular hairs; anthers reniform, basifixed; staminode 1, adnate to base of corolla tube, 5-6 mmlong. Pistil 3.1-3.5 cmlong when mature; ovary cylindrical, 2-2.2 cmlong, glabrous; style 1-1.3 cmlong, with white glandular hairs; stigma 1, flattened with central depression. Disc ringlike, yellowish, 2-3 mmhigh. Capsule straight, cylindrical, 2.1-2.5 cmlong.  Distribution, habitat and phenology. This new species is endemic to Sa Pa, northern Vietnam and grows densely on cliffs by waterfalls along deep valleys in evergreen broad-leaved forests, at an elevation of around 1800-2010 m. Flowering from August to October and fruiting from September to October.  Etymology. The species epithet refers to the large size of the flowers. Based on the authors'observation and other relevant publications ( Wang et al. 1990, 1998), the new species has one of the largest flowers in  Oreocharis.  Conservation status. This new species appears to be restricted to a very moist habitat in Sa Pa, Lao Cai Province, northern Vietnam. It grows on several steep cliffs at 1800-2100 m elevation by waterfalls with flowing water throughout the year (Fig. 1A). It flowers during the rainy season (September to October), during which the locality is inaccessible. This is likely the reason why it had not previously been discovered. It is naturally protected by its inaccessible habitat on the cliffs. According to our observations in the field, the two known populations harbour about 100 mature individuals in each. In fact, there are many waterfalls at this altitudinal range and, thus, the real number of populations and individuals may behigher. Nevertheless, its unusually humid habitat might be affected by climate change-induced droughts. Overall however, the species has been classified as "Data Deficient" [DD] following IUCN Red List Categories and Criteria ( IUCN 2012).   Figure 1.  Oreocharis grandifloraW.H.Chen, Q.H.Nguyen & Y.M.Shui, sp. nov. ( A-F) and  O. flavidaMerr. ( G-I) AHabitat (red arrows indicate position of plants in the field) BMature plant CAbaxial leaf surface DFront view of flower ELateral view of flower FOpened corolla, pistil, disc and calyx GPlant HInflorescence and open flowers IDissected flower, showing corolla with free anthers, pistil, disc and calyx. Scale bars: A, C-F= 1 cm; B,G= 2 cm; H, I= 5 mm. All photographs by Yu-Min Shui.  Additional specimens examined.   VIETNAM. Lao Cai, Sa Pa distr., Ta Phin cave, in secondary forests, 22°20'43.66"N, 103°46'30.48"E,  2017 melevation, 30 October 2012, in fruit,  Q.H.Nguyen, T.H.Nguyen, Y. M. Shui, Y. K. Sima, S. X. Yang, Z. Zhou, J. LiuCK687(KUN!, Herbariumof the Centrefor Plant Conservation, Vietnam Union of Scienceand Technology Associations, Hanoi!).  Notes. This new species resembles  Oreocharis flavida, but differs in the characters in Table 1(see also Fig. 1). Additionally, the corolla size range is larger than any other species in the former delimitation of  Oreocharis. In size and shape, the corolla of the new species resembles that of  Oreocharis ronganensis(K.Y. Pan) Mich. Moeller& A. Weber (formerly  Ancylostemon ronganensisK.Y. Pan), but in the latter the corolla is pink, not deep orange. This is a rare colour in  Oreocharis s.l., since only about six of the>106 species have a corolla of such an intensely deep orange colour.   Table 1.Morphological comparison between  Oreocharis grandiflorasp. nov. and  O. flavidaMerr.    Character   O. grandiflorasp. nov.   O. flavida   Petiole 2.2-2.6 cm long, white long glandular hairs 13-16 cm long, densely pale brown villous or woolly   Leaf blade narrowly oblong or elliptic, 4-6 x1.8-3.5 cm, adaxially and abaxially glandular, densely glandular on veins ovate-elliptic to broadly ovate, 4-10 x2-7.2 cm, adaxially densely pubescent, abaxially densely brown woolly, more densely along veins   Leaf base cuneate cordate to rounded   Peduncle densely glandular densely pale brown woolly   Calyx outside glandular outside eglandular villous   Corolla 3.3-3.6 cm long, outside white glandular 1.5-1.7 cm long, outside sparsely pubescent   Corolla tube infundibuliform campanulate   Corolla lips adaxial lobes 8.5-9 x11-12 mm, apex obtuse; abaxial lip 3-lobed, lobes 13-14 x8-9 mm all lobes slightly equal, 3-6 x3-5 mm.   Stamens 4, anthers coherent in two pairs; anthers reniform 4, anthers not coherent; anthers horseshoe-shaped   stigma 1 2   disc 2-3 mm tall 1 mm tall 2012-10-30 2013-09-07 2012-10-30 Kunming Botanic Garden, Y. M. Shui, Herbarium, Centre, Plant Conservation, Technology Associations VIETNAM Sa Pa distr. 2017 22.34546 Vietnam Union of Science 1 103.77514 Ta Phin cave 1 Lao Cai holotype 2012-10-30 Q. H. Nguyen, T. H. Nguyen, Y. M. Shui, Y. K. Sima, S. X. Yang, Z. Zhou, J. Liu, Herbarium, Centre, Plant Conservation, Technology Associations VIETNAM Sa Pa distr. 2017 22.34546 Vietnam Union of Science 1 103.77514 Ta Phin cave 1 Lao Cai