Billolivia violacea D.J.Middleton & H.J.Atkins, 2014

Billolivia violacea D.J.Middleton & H.J.Atkins View in CoL , sp. nov. ( Fig. 3 View FIGURE 3 , 7 View FIGURE 7 )

Most similar to Billolivia longipetiolata from which it can be distinguished by the generally shorter petioles 6−12.5 cm vs. 9−18 cm in B. longipetiolata ), the minutely dentate lamina margin (coarsely dentate in B. longipetiolata ), the calyx fused into a tube for 4−6 mm (7–9 mm in B. longipetiolata ), and the violet tips to the corolla lobes (pink or red in B. longipetiolata ).

Type:— VIETNAM. Lam Dong, Duc Trong District, Nui Voi, Xa Hiep An , 1550 m alt., RBGE acc. no. 20010642, 17 September 2001, vouchered as D.J. Middleton 4210 (holotype E) .

Rhizomatous short-stemmed compact herb; stems with long brown multicellular uniseriate hairs to 5 mm long. Leaves alternate, internodes very short; petioles 6−12.5 cm long, hairs as on stems, to 5.5 mm long; lamina narrowly ovate to narrowly elliptic, 9.2−20 × 3.1−4.8 cm, 3.4−4.2 times as long as wide, base equal to unequal, rounded to cuneate, apex acute to short acuminate, margin minutely dentate, secondary venation 10−13 veins on each side of midrib with weaker intersecondaries between, tertiary venation alternate percurrent, adaxial lamina glabrous or with very few hairs on midrib, margin ciliate, abaxial lamina with shorter hairs c. 0.5 mm long between the veins and both short and long hairs to 5 mm long on midrib and venation. Inflorescences axillary, ± sessile, 4−12-flowered; bracts ovate, thin, to 23 × 7 mm, sparsely pubescent with long brown hairs; pedicels 17−25 mm long, densely covered in long brown hairs. Calyx 11 mm long, composed of a tube and 5 ± equal lobes, densely long brown pubescent outside, with sessile glands inside; tube 4−6 mm long; lobes narrowly triangular, 6−10 × 2−2.5 mm, reflexed, apex narrowly acute. Corolla c. 36 mm long, composed of a narrow tube which slightly flares towards mouth and a 2-lipped limb, tube and base of lobes white outside and inside, tips of lobes violet outside and inside, inside base of lower lip yellow; tube c. 22 mm long; upper lip 2-lobed, c. 11.5 mm long, sinus between lobes c. 8 mm, lobes oblong, c. 8 × 7 mm, apices rounded; lower lip 3-lobed, c. 14 mm long, lobes slightly obovate, apices rounded, lateral lobes c. 11 × 8 mm, medial lobe c. 10 × 9 mm; corolla with short colourless hairs outside on upper half of tube and base of lobes, glandular puberulent at top of tube and base of lobes inside. Stamens inserted at c. 15 mm from corolla base; filaments strongly coiled, c. 7 mm long, narrow at base, abruptly widening around middle, with sessile glands in upper half; anthers c. 1.3 × 1.3 mm, glabrous, adhering at the apices; lateral staminodes c. 3 mm long, medial staminode c. 1.5 mm long. Disc an annular ring, c. 2.2 mm high. Ovary c. 5.5 mm long, glabrous at base, glandular puberulent in upper part; style c. 12 mm long, glandular puberulent; stigma 2- lobed, lobes 1.5 mm long. Fruit ellipsoid (as reported, not seen by authors).

Etymology: — After the colour of the tips of the corolla lobes.

Distribution: — Only known from the type locality.

Ecology: — Submontane tropical evergreen closed forest at 1550 m alt.

Proposed IUCN conservation status: — Data Deficient (DD) ( IUCN 2001, 2012). This species is only known from one collection from the wild and one grown on in cultivation from that collection. Its distribution, and the current state of the forest in the area, are unknown although the suitable forest habitat in the region is very likely to be much less than 5000 km 2 which could qualify it for at least an Endangered category given the deforestation in the region.

Additional specimen studied: — VIETNAM. Lam Dong: Duc Trong District, Nui Voi, Xa Hiep An , 1550 m alt., 17 September 2001, Thomas, Luu & Chi 201 ( E, VNM) .

The type collection is a voucher taken from a plant cultivated at the Royal Botanic Garden Edinburgh which in turn was grown on from a cutting taken from the only wild collected specimen, Thomas et al. 201. The cultivated voucher is chosen as the type as it better shows the essential characters than the wild collected specimen.