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

Billolivia minutiflora D.J.Middleton & H.J.Atkins View in CoL , sp. nov. ( Fig. 3 View FIGURE 3 , 5 View FIGURE 5 , 6 View FIGURE 6 )

Most similar to Billolivia vietnamensis but differs in the sparsely pubescent abaxial surface of the leaves, the short hairs on the adaxial leaf surface, the smaller flowers, the pubescence on the inside of the corolla tube to only just below stamens (from the stamens to just above the base in B. vietnamensis ) and the glabrous ovary (pubescent distally in B. vietnamensis ).

Type:— VIETNAM. Lam Dong Province, Da Hoai District, Deo Chuoi , 216 m alt., 20 June 2008, Tran Huu Dang et al. 55 (holotype E, isotypes P , RUPP , SING , VNM ).

Caulescent herb to 70 cm tall; stems with brown hairs to 2.5 mm long, glabrescent with age. Leaves alternate, crowded near stem apex but with internodes up to 1.5 cm long; petioles 1.5−6.5 cm long, with sparse long brown multicellular uniseriate hairs to 3 mm long throughout; lamina narrowly ovate to narrowly elliptic, 7.8−13 × 3.5−5.3 cm, 1.8−2.5 times as long as wide, base equal to slightly unequal, cuneate to obtuse, apex short acuminate, margin minutely dentate (but obscured by hairs), secondary venation 8−12 veins on each side of midrib with few weaker intersecondaries between, tertiary venation alternate percurrent, adaxial lamina with very few scattered short hairs, margin densely ciliate, abaxial lamina with appressed brown hairs to 1.5 mm long on midrib and venation. Inflorescences axillary, short, ± sessile, 1−4(–6) flowered; bracts small, linear, c. 5 × 1 mm, densely pubescent; pedicels 5−8.5 mm long, densely pubescent. Calyx of 5 lobes almost divided to base; lobes narrowly ovate, 4.7−5 × 1−1.4 mm, apex caudate, outside densely covered in long eglandular hairs to 2.2 mm long, inside glabrous. Corolla 12−15 mm long, composed of a narrow tube and spreading limbs, the lower lip of which is longer than the upper, white with violet veins and with yellow or orange-yellow patch on lower lip; tube 8−9 mm long; upper lip 2-lobed, 1.9−2 mm long, sinus between lobes 1.6 mm, lobes elliptic to broadly orbicular, c. 1.6 × 1.5−3 mm, apices rounded; lower lip 3-lobed, 4−6 mm long, lobes slightly obovate, apices rounded, lateral lobes 2.5−3.5 × 1.9−4 mm, median lobe 2.5−4 × 2−4.2 mm; corolla outside glabrous at base of tube, with long hairs in upper 1/3 of tube and on lobes, inside with ring of eglandular hairs around height of stamen insertion which is denser around actual filament insertion, then sparsely short glandular pubescent above this, then densely short glandular pubescent in throat and on inside of upper lip, longer glandular hairs and few eglandular hairs on inside of lower lip, glabrous at apices of lobes and on most of lateral lobes. Stamens inserted at 4.5−5.1 mm from corolla base; filaments slightly curved, 1.7−1.8 mm long, glabrous; anthers 1.4−1.5 × 1−1.1 mm, glabrous, held face to face, adhering at the apices; lateral staminodes c. 0.5 mm long, medial staminode c. 0.3 mm long. Disc of a ring which is 5-lobed at apex, lobes sometimes breaking free, 0.7−1.8 mm high. Ovary 1.5−2.5 mm long, glabrous; style 3−5 mm long, glabrous at base, glandular hairs in upper half; stigma 2-lobed, lobes 0.4 mm long. Fruit ellipsoid, 2–8 mm long, 5 mm wide, densely pubescent. Seeds ellipsoid, c. 0.3 × 0.2 mm.

Etymology: — In reference to the small flowers.

Distribution: — Vietnam, Lam Dong Province.

Ecology: — Terrestrial or in rocky stream beds in primary lowland tropical evergreen forest at 200–600 m altitude.

Proposed IUCN conservation status: — Critically Endangered (CR B1ab(iii)) ( IUCN 2001, 2012). The known Extent of Occurrence for this species is far less than 100 km 2 and at least one of the two known collections was made close to agricultural land in an area where there are now only small forest fragments.

Additional specimen studied: — VIETNAM. Lam Dong: Da Hoai District, Bao Loc Pass, Da Me area , 600 m alt., 22 June 2008, Ly Ngoc Sam 498 ( E, VNM); km 150 Saigon-Dalat , March 1964, Schmid s.n. ( P) .

The lobes of the lower corolla lip in Ly 498 are narrower than in the type collection but in all other essential characters the two collections match. Although the ovary is quite clearly glabrous, after fertilisation the fruits of both specimens are pubescent. Further collections are necessary to understand the variation in this taxon.