Billolivia middletonii N.S. Lý, 2017
|
publication ID |
https://doi.org/ 10.11646/phytotaxa.291.1.9 |
|
persistent identifier |
https://treatment.plazi.org/id/B2638781-C331-FFA4-FF63-FA37EC75E918 |
|
treatment provided by |
Felipe |
|
scientific name |
Billolivia middletonii N.S. Lý |
| status |
sp. nov. |
Billolivia middletonii N.S. Lý View in CoL , sp. nov.
Similar to B. kyi in the long pubescent petioles, the shape of the lamina, and the 5-lobed ovate calyx almost divided to base, but differing in the glabrous stems (vs. densely pubescent), the lamina being glabrous adaxially (vs. sparsely pubescent adaxially), much longer bracts, 25–52 mm long (vs. shorter, up to 15 mm long), the oblong-obovate corolla lobes with violet lines (vs. orbicular, dark to redpurple), the white corolla throats having two yellow patches at base of lower lip, with violet lines (vs. dark red with a yellow patch), the longer and pale greenish filaments, 8–10 mm long (vs. white with long red patch, 5–6 mm long), fruit 20–25 mm long, ovoid to oblong-ovoid (vs. 14–16 mm long, ellipsoid).
TYPE:— VIETNAM. Quảng Ngãi Province, Tây Trà District, Trà Trung Commune, Cà Ðam Mountains, Bà Noong stream, 1009 elev., 25 September 2016, Lý Ngọc Sâm, Lý-817 (holotype VNM!, isotypes P!, VNM!). Fig.1 View FIGURE 1 & 2 View FIGURE 2 .
Lithophytic, caulescent, perennial herbs with short decumbent stems, robust, to 30 cm long, 1.8–2.2 cm in diam., light brown, with numerous strongly prominent leaf scars, glabrous, except for sparse hairs to 2 mm long at apex in young plants ( Fig.1A, C View FIGURE 1 ). Leaves alternate, crowded near stem apex, internodes 0.8–1.8 cm long, with roots at the nodes near base; petioles fleshy, 9.2–18.5 cm long, 0.5–0.7 cm in diam. at the middle, pale greenish, densely covered in a mixture of long brown hairs to 4.5 mm long and shorter appressed brown hairs toward apex, hairs sparse at base; lamina thick, coriaceous, slightly unequal, elliptic-obovate to broadly elliptic, 12.5–21.5 × 9–14.5 cm, base obtuse to somewhat truncate, attenuate when young, apex short acute to slightly obtuse, margin coarsely crenate, slightly deflexed, secondary venation 10–13 veins on each side of midrib, sunken above, strongly prominent below, with weaker intersecondaries veins between, tertiary venation alternate percurrent, adaxial lamina dark green, glabrous, margin ciliate with brown hairs to 2.5 mm long, abaxial lamina glaucous greenish, with sparsely brown hairs to 3 mm long between the veins and densely so with both short and long brown hairs to 3.5 mm long on midrib and venation ( Fig. 1D View FIGURE 1 ). Inflorescences axillary, single or distichously compound-cymes, peduncle pale brown-red to tinged greenish, densely short brown pubescent to 1.5 mm long; simple cymes with a peduncle 6.5–13 mm long and 2–3 mm in diam., 6–8-flowered, compound cymes with peduncle 7–13.5 mm long, 3–3.5 mm in diam. and second axes 2–6 mm long, 2–3 mm wide in diam., sometimes sessile, 4–8-flowered in each cyme; bracts narrowly ovate, with a longitudinally prominent vein on the outside, outside pale brown-red [pinkish], tinged pinkish-green towards apex, with sparsely short brown pubescence to 1.5 mm long, denser in the middle, inside whitish or greenish, glabrous, apex acute, ciliate, margin ciliate with brown hairs to 2 mm long ( Fig. 1I–J View FIGURE 1 ); basal bracts (25–)32–52 × 7–9 mm, second bracts [of the subtending second cyme] 24–39 × 5–7 mm; pedicels 18–24 mm long, 1.8–2.5 mm diam. in the middle, pale brown-red [pinkish] or greenish, densely brown pubescent to 2.5 mm long. Calyx of 5 ± equal lobes, almost divided to base with connate part <1 mm long, 21–26 mm long, 3–4 mm wide at widest point, apex acute, margin ciliate, with a longitudinally prominent vein on the outside, pale brown-red [pinkish] to greenish outside with sparse brownish hairs of 2 mm long, paler and glabrous inside ( Fig. 1L View FIGURE 1 ). Corolla 21–25 mm long, composed of a narrow tube which slightly curves downwards in lower ⅓ and slightly flares towards mouth, and a 2-lipped limb, tube and lobes white outside, with dark violet lines from the upper half of the inside of the tube and onto lobes, ventral surface of throat and upper half of tube with 2 yellow stripes in line with lobe sinuses, upper halves of lobes white ( Fig. 1K1–K View FIGURE 1 3, M); tube 16–19 mm long, 10–11 mm wide at throat; upper lip 2-lobed, ca. 10–12 mm long, sinus between lobes ca. 5 mm, lobes 7–11 × 5.5–8 mm; lower lip 3-lobed, c. 16–18 mm long, lobes somewhat oblong-obovate, apices rounded, lateral lobes ca. 8–12 × 6.5–9 mm, medial lobe 9.5–14 × 6–8 mm; corolla outside glabrous in basal half of tube, with sparse short white hairs in upper half, with short and long hairs on upper part of tube and outside of lobes, tube inside glabrous and with short glandular hairs on inside basal 2/3 of lobes. Stamens inserted at ca. 10 mm from corolla base ( Fig. 1M–N View FIGURE 1 ); filaments ca. 8–10 mm long, narrow at base, widening around middle and slightly curved, white at base, pale greenish towards apex, with dense glandular hairs in upper half; 2 fertile anthers ca. 2–3 × 2–3 mm, thecae ± parallel, 2 anthers fused by tips; lateral staminodes minute, ca. 1.5 mm long, white, glabrous; medial staminode minute, ± 1 mm long, white, glabrous. Disc bowl-shaped, shallowly 5-lobed, ca. 1–1.5 mm high, 2.5–3 mm in diam., white, glabrous. Ovary ca. 5.5–6 mm long, 2–3 mm wide at base, white glandular pubescent at apex ( Fig. 1O View FIGURE 1 ); style 6–8 mm long, white, densely white glandular pubescent throughout with hairs up to 1 mm long; stigma 2-lobed, 1–2 mm long, 1.5–2 mm wide, lobes ca. 1 mm long, glabrous. Fruits narrowly ovoid to oblong-ovoid, 20–25 × 5–6.5 mm, translucent greygreenish, with sparse hairs at apex ( Fig. 1G View FIGURE 1 ). Seeds many, ovoid, 0.2–0.3 × 0.2 mm, black.
Distribution and Ecology: —Currently known only from the type locality in the Cà Đam Mountains, where two subpopulations of mature, flowering and fruiting plants of Billolivia middletonii were found. It grows in rocky stream beds in lower primary sub-montane evergreen broadleaf forest at about 1000 elev. It is locally abundant.
Phenology:— Billolivia middletonii was observed with mature fruits in late July and in flower and with young fruits in late September in its natural habitat. This would suggest it flowers several times per year with flowering from May to September, and fruiting from July to December.
Conservation status: —Critically Endengered (CR B2a,b(ii,iii)). Billolivia middletonii occurs in a single locality on Cà Ðam Mountains with fewer than 100 individuals and with a total Area of Occupancy of less than <0.5 km 2. Although this species is under the protection of the local authorities of the Department of Forest Protections in Tây Trà and Trà Bồng Districts, Quảng Ngãi Province, the populations are, however, vulnerable and continuing to decline in area, extent and quality of habitat due to destruction through human activities, such as harvesting of timber and non-forest products, especially clearing of forest land for Acacia plantations. According to the IUCN Red list criteria ( IUCN, 2012), this qualifies it as Critically Endengered (CR B2ab(ii,iii)) which is therefore proposed here.
Additional specimens examined (Paratypes): — VIETNAM. Qu ảng Ngãi Province , Tây Trà District , Trà Trung Commune , Cà Ðam Mountains, Bà Noong stream, 1009 m elev., September 2016, Lý Ngọc Sâm, Lý-816 (VNM!) ; the same locality, 29 July 2016, Lý Ngọc Sâm, Lý-784 (VNM!) ; the same locality, 1008 m elev., 25 September 2016, Lý Ngọc Sâm, Lý-815 (VNM!) .
Etymology: —The specific epithet of the new species is named in honour of Dr David J. Middleton of the Singapore Botanic Gardens for his continuing contribution to our understanding of the Gesneriaceae in Asia, including as the first author on the paper in which the genus Billolivia was first described.
Notes: —The calyx in Billolivia is more or less divided to the base in some species and fused into a tube in others. The species with the calyx divided to base are B. kyi Luu & Tran in Luu et al. (2015: 362), B. minutiflora Middleton et al. (2014a: 258) , B. poilanei Middleton et al. (2014a: 260) , B. vietnamensis Middleton et al. (2014a: 261) , and the new species ( Figure 1L View FIGURE 1 ). Of these, B. kyi and B. middletonii differ substantially from the other three species in having much longer petioles to ≥ 9 cm long. Billolivia middletonii differs from B. kyi in the morphological features noted above. Billolivia middletonii also resembles B. longipetiolata Middleton et al. (2014a: 256) and B. tichii Luu et al. in Vũ et al. (2015: 190) in having long pubescent petioles, obovate to elliptic leaves, and ovate calyx lobes. Densely pubescent stems, coarsely dentate margins, elliptic or deltoid lobes of the tubular calyx, corolla lobes being orbicular to deltoid with violet or red to pink apexes, and glabrous ovaries distinguish these species from B. middletonii .
The currently known species of Billolivia are found in a relatively small area in the southern Annammite Mountains on the Ðà Lạt plateau (Lâm Đồng Province) and in Bình PhƯớc and Ninh Thuận Provinces in Vietnam ( Figure 2 View FIGURE 2 ). The species are small terrestrial herbs and are quite locally endemic ( Middleton et al. 2014a, 2014b, Luu et al. 2015, Vũ et al. 2015). With the new species described here, nine species of Billolivia are now recorded, all of them from Vietnam. The genus, is, however reported for the first time from Quảng Ngãi Province which extends the distribution range of the genus from Southern to Central Vietnam and ca. 400 km further north than previously known localities for the genus (see Figure 2 View FIGURE 2 ). Further field work in the Annamite mountains is necessary to see if the distributional limit of Billolivia species in Vietnam could be even further to the north.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.