taxonID	type	description	language	source
90451360FFCA3104FF564F9E52D5F73F.taxon	materials_examined	Type: — VIETNAM. Phú Yên Province: Sông Hinh District, Mt. Hòn Đen, approximate coordinates 12 ° 53 ’ 52 ” N and 108 ° 48 ’ 40 ” E, at ca. 600 m elevation, 20 January 2017, Tr ần H ữu Đăng, Nguy ễn Tr ần Qu ốc Trung, Nguy ễn Qu ốc Đ ạt, Vũ Ng ọc Long NF-BOL-PY 002 (holotype SGN!, isotypes SGN!, PHH!, HNU!, VNMN!). Terrestrial herb to 20 cm tall; stems rhizomatous, creeping and then erect, sparsely pubescent with brown multicellular uniseriate hairs to 3 mm long. Leaves alternate; petioles 3 ‒ 9 cm long, densely pubescent with brown multicellular uniseriate hairs to 3 mm long; lamina ovate, slightly asymmetric, 9 ‒ 14 cm long, 5.0 ‒ 9.0 cm wide, base round, apex subacute, margin coarsely dentate, 8 ‒ 10 secondary veins on each side of midrib, adaxial lamina dark green, glabrous, margin densely ciliate, abaxial lamina pale green, with dense brown appressed hairs to 2 mm long. Inflorescences axillary, 3 ‒ 9 - flowered; peduncle white, to 8 mm long, densely pubescent; ray white, to 1 mm long, densely pubescent; bracts lanceolate to narrowly triangular, to 9 × 3 mm, abaxially densely pubescent, apex acute, margins ciliate; pedicels white, 2 ‒ 2.5 cm long, distally sparsely pubescent, basally densely pubescent. Calyx of 5 lobes almost divided to base, greenish white, outside densely long brown pubescent, inside glabrous; lobes triangular, to 8 mm long, to 3 mm wide at base, apex acute, with ciliate margins. Corolla 26 ‒ 28 mm long, composed of a narrow tube which slightly flares towards an oblique mouth and a 2 - lipped limb with lobes recurved; tube 14 mm long, white, outside pubescent, inside glabrous; throat white, with shortly stalked to subsessile glands and purple lines on the base of lobes; upper lip 2 - lobed, lobes 6 − 7 × 12 − 13 mm, ovate; lower lip 3 - lobed, lateral lobes elliptic, 5 − 6 × 10 − 11 mm, lower lobe slightly obovate, 7 − 8 × 5.5 − 6 mm; all lobes citrus yellow, outside sparsely pubescent with multicellular uniseriate hairs, inside with shortly stalked glands. Stamens inserted at 6 ‒ 7 mm from corolla base; filaments slightly curved, 7 ‒ 8 mm long, white with a red dot in the middle, sparsely glandular puberulent. Disc bowl-shaped, 5 - lobed at apex, 1 mm high. Ovary 3 ‒ 3.5 mm long, 2 mm in diameter, with dense stalked glands on apical 1 / 3; style 7 ‒ 8 mm long, densely covered with glandular hairs; stigma slightly lobed, ciliate. Fruits ovoid, greenish cream, 14 − 16 × 6 − 8 mm, mostly brown puberulent, basally glabrous, translucent when ripe; seeds many, ovoid, 0.15 × 0.2 mm, black.	en	Trư ờng, Lưu H ồng, Đăng, Tr ần H ữu, Nhân, Ph ạm H ữu, Trung, Nguy ễn Tr ần Qu ốc, Đ ạt, Nguy ển Qu ốc, Long, Vũ Ng ọc (2018): Two new species of Billolivia (Gesneriaceae) with yellow flowers from Vietnam. Phytotaxa 362 (2): 227-232, DOI: 10.11646/phytotaxa.362.2.9, URL: http://dx.doi.org/10.11646/phytotaxa.362.2.9
90451360FFCA3104FF564F9E52D5F73F.taxon	distribution	Distribution, habitat, and phenology: — Found on moist gulleys in montane moist evergreen closed forest at around 600 m in elevation, Mt. Hòn Đen, Sông Hinh District, Phú Yên Province, Vietnam. Flowering and fruiting were seen in December and January.	en	Trư ờng, Lưu H ồng, Đăng, Tr ần H ữu, Nhân, Ph ạm H ữu, Trung, Nguy ễn Tr ần Qu ốc, Đ ạt, Nguy ển Qu ốc, Long, Vũ Ng ọc (2018): Two new species of Billolivia (Gesneriaceae) with yellow flowers from Vietnam. Phytotaxa 362 (2): 227-232, DOI: 10.11646/phytotaxa.362.2.9, URL: http://dx.doi.org/10.11646/phytotaxa.362.2.9
90451360FFCA3104FF564F9E52D5F73F.taxon	etymology	Etymology: — The epithet refers the citrus yellow colour of its corolla lobes. Vietnamese name: — LƯu hoa vàng chanh. Proposed IUCN conservation status: — Billolivia citrina has been known only from the type location, where it is not commonly encountered. Our surveys in the province over the last several years have not found additional populations of the species. This new species appears to have a restricted distribution confined to forests of Song Hinh District with a total area of <400 km 2 where deforestation for agricultural expansion is occurring. The species, therefore, should be considered for listing in the Endangered category, EN B 2 a & b (i & ii) (IUCN 2012). Notes: — Billolivia citrina is similar to B. yenhoae in having yellow corolla lobes but differs in many characters: ovate leaves, much shorter peduncles, smaller flowers, citrus yellow corolla lobes, slightly curved filaments, and apically hairy ovaries. Billolivia citrina is also morphologically close to B. cadamensis in having short stems, glabrous adaxial laminae, hairs mainly on abaxial midribs and veins, calyces divided into 5 lobes to base, shape of corolla and lobes, corolla throat with purple lines on the base of lobes and white glandular puberulent filaments with a red dot in the middle. The later species, however, has elliptic leaf laminae, glabrous bracts, brownish red calyces, and white corolla lobes. The purple lines in the corolla of B. citrina recall those of B. cadamensis, B. tichii, B. vietnamensis, and B. moelleri but these species have white and / or purple corolla lobes.	en	Trư ờng, Lưu H ồng, Đăng, Tr ần H ữu, Nhân, Ph ạm H ữu, Trung, Nguy ễn Tr ần Qu ốc, Đ ạt, Nguy ển Qu ốc, Long, Vũ Ng ọc (2018): Two new species of Billolivia (Gesneriaceae) with yellow flowers from Vietnam. Phytotaxa 362 (2): 227-232, DOI: 10.11646/phytotaxa.362.2.9, URL: http://dx.doi.org/10.11646/phytotaxa.362.2.9
90451360FFC83102FF564C0C5583F6AF.taxon	materials_examined	Type: — VIETNAM. Khánh Hòa Province: Khánh Vĩnh District, SƠn Thái Commune, approximate coordinates 12 ° 13 ’ 01 ” N and 108 ° 44 ’ 50 ’’ E, at 1,061 m elevation, 01 November 2013, Lưu H ồng Trư ờng KH 0941 (holotype SGN!; isotypes SGN!). Terrestrial herb to 20 cm tall, stoloniferous; stems to 10 cm, internodes congested; stolons up to 60 cm long, densely pubescent. Leaves alternate; petioles 4 ‒ 9 cm long, densely pubescent with brown multicellular uniseriate hairs to 4 mm long; lamina obovate to oblanceolate, slightly asymmetric, 13 ‒ 20 cm long, 6 ‒ 7 cm wide, base round to cuneate, apex subacute to acute, margin coarsely dentate, 8 ‒ 10 of secondary veins on each side of midrib, adaxial lamina dark green, with sparse erect brown hairs to 3 mm long when young, glabrous when mature, margin densely ciliate, abaxial lamina pale green, with dense erect brown hairs to 5 mm long on midrib and venation, glabrous on lamina between veins. Inflorescences axillary, thyrse, to 15 - flowered; peduncle light green, 10 ‒ 52 cm long, densely pubescent; ray white to light green, to 15 cm long, pubescent; bracts oblong to oblanceolate, light green, to 3.5 × 1 cm, apex acute, abaxially densely pubescent, with ciliate margins; pedicels white, 4 ‒ 5.5 cm long, pubescent. Calyx of 5 lobes almost divided to base, white to light green, outside densely brown long pubescent, inside glabrous; lobes narrowly triangular, to 12 mm long, to 2 mm wide at base, apex acute, with ciliate margins. Corolla 28 − 34 mm long, composed of a narrow tube and a 2 - lipped limb with lobes recurved; tube 18 ‒ 21 mm long, white, contracted below the middle, then slightly flaring towards mouth, outside pubescent, inside glabrous; throat yellow, glabrous and with purple lines; upper lip 2 - lobed, lobes 1.3 − 1.5 × 9 − 11 mm, ovate; lower lip 3 - lobed, lobes slightly obovate, 12 − 14 × 8 − 9 mm; all lobes bright yellow, with purple lines at base, outside sparsely pubescent with multicellular uniseriate hairs to 5 mm, inside with shortly stalked glands. Stamens inserted at the middle of the corolla tube; filaments 6 ‒ 7 mm long, strongly S-curved, white, with sparse glandular hairs on upper half. Disc bowl-shaped, obscurely 5 - lobed, 1.5 mm high. Ovary 5 ‒ 5.5 mm long, 2.5 mm in diameter, fully covered with dense stalked glands; style 13 ‒ 14 mm long, densely covered with glandular hairs; stigma 2 - lobed, ciliate. Fruits ovoid, around 10 × 0.6 mm, brown hairy, translucent violet and with persistent style. Additional specimens examined (paratypes): — VIETNAM. Khánh Hòa Province: Khánh Vĩnh District, SƠn Thái Commune, approximate coordinates 12 ° 13 ’ 01 ” N and 108 ° 44 ’ 50 ’’ E, at 1,040 m elevation, 12 November 2016, Lưu H ồng Trư ờng, Nguy ễn Qu ốc Đ ạt & Nguy ễn Tr ần Qu ốc Trung NF-BOL-KH 036 (SGN!); 26 November 2016, Ph ạm H ữu Nhân & Lưu H ồng Trư ờng PHN 12 - 01 (SGN!, PHH!, HNU!, VNMN!).	en	Trư ờng, Lưu H ồng, Đăng, Tr ần H ữu, Nhân, Ph ạm H ữu, Trung, Nguy ễn Tr ần Qu ốc, Đ ạt, Nguy ển Qu ốc, Long, Vũ Ng ọc (2018): Two new species of Billolivia (Gesneriaceae) with yellow flowers from Vietnam. Phytotaxa 362 (2): 227-232, DOI: 10.11646/phytotaxa.362.2.9, URL: http://dx.doi.org/10.11646/phytotaxa.362.2.9
90451360FFC83102FF564C0C5583F6AF.taxon	distribution	Distribution, habitat and phenology: — Growing in scattered clumps on moist gulleys in montane moist evergreen closed forest at around 1,060 m elevation, SƠn Thái Commune, Khánh Vĩnh District, Khánh Hòa Province, Vietnam. Flowering was seen in November to January.	en	Trư ờng, Lưu H ồng, Đăng, Tr ần H ữu, Nhân, Ph ạm H ữu, Trung, Nguy ễn Tr ần Qu ốc, Đ ạt, Nguy ển Qu ốc, Long, Vũ Ng ọc (2018): Two new species of Billolivia (Gesneriaceae) with yellow flowers from Vietnam. Phytotaxa 362 (2): 227-232, DOI: 10.11646/phytotaxa.362.2.9, URL: http://dx.doi.org/10.11646/phytotaxa.362.2.9
90451360FFC83102FF564C0C5583F6AF.taxon	etymology	Etymology: — The species is named after the first author’s beloved wife LƯƠng Th ị Yên Hòa for her invaluable support for his interest in botany. Vietnamese name: — LƯu hoa Yên Hòa. Proposed IUCN conservation status: — The species is only known from a single population of less than 250 individuals growing in a less than 1 km 2 watershed of an unnamed stream, which is less than 100 m away from a recently built national road. We have not found any additional populations even though we have been surveying biodiversity in the whole Khánh Hòa Province and neighbouring provinces since 2012. This is a really rare species distributed in a forest where human impacts, including illegal logging, are common. This species, therefore, should be considered for listing in the Critically Endangered category, CR B 2 a & b (i, ii & iii) (IUCN 2012). Notes: — Billolivia yenhoae is the first taxon in the genus known to have vegetative propagation by stolons, which may form colonies in separated gulleys. It grows with an undescribed Billolivia with distinguishably hairy leaves, which will be the subject for another paper. Billolivia yenhoae has the longest peduncles in the genus. Its yellow flowers recall those in B. citrina but B. yenhoae is distinct in having obovate to oblanceolate leaves, much longer peduncles, larger flowers, bright yellow corolla lobes, S-curved filaments, and fully hairy ovaries.	en	Trư ờng, Lưu H ồng, Đăng, Tr ần H ữu, Nhân, Ph ạm H ữu, Trung, Nguy ễn Tr ần Qu ốc, Đ ạt, Nguy ển Qu ốc, Long, Vũ Ng ọc (2018): Two new species of Billolivia (Gesneriaceae) with yellow flowers from Vietnam. Phytotaxa 362 (2): 227-232, DOI: 10.11646/phytotaxa.362.2.9, URL: http://dx.doi.org/10.11646/phytotaxa.362.2.9
