Gomphostemma repentum 3ongch (Prain, 1891)

Bongcheewin, Bhanubong, Ingrouille, Martin J. & Paton, Alan J., 2022, A revision of Gomphostemma (Lamiaceae), Kew Bulletin 77 (1), pp. 27-92 : 77

30. Gomphostemma repentum 3ongch . sp. nop.

Type: Upper Burma, Karenni, Ywathit, Salween Valley, 600 m [2000 ft], 11 Jan. 1913, Micholitz s.n. (holotype K [K001081923]).

http://www.ipni.org/urn:lsid:ipni.org:names:55221338-1

Climbing herb. Stems slender, scrambling, obtusely quadrangular, with longitudinal grooves, with dense stellate hairs; internodes curving appearing wavy, always twisting. Leaoes petiolate, chartaceous; blades ovate, 10 – 13 × 5 – 9 cm, apex acute, margin obtusely serrate, base attenuate or round, upper side with coarse 1 – 3-celled simple hairs, bifurcate hairs and stellate hairs confined on midrib; petioles 20 – 60 mm long, with dense stellate hairs. Inflorescence axillary, upright, 30 – 50 mm long, with opposite cymes elongate, raceme-like, unbranched then congested with axis not visible between cymes, inserted at the upper nodes at which leaves are usually present; verticils few-flowered; bracts broadly ovate, 10 – 13 × 10 – 13 mm, apex acute, margin serrate, base obtuse, upper side with a mixture of hairs, lower side with dense stellate hairs; bracteoles linear, 3 – 5 mm long. Flowering calyx infundibular, 10 – 12 mm long, 10-ridged, outside with dense stellate hairs, inside with adpressed simple hairs; tube 5 – 8 mm long; lobes triangular, 3 – 2 mm long, 1.3 – 2.3 mm wide at base. Fruiting calyx not seen. Corolla yellow, 20 – 23 mm long, throat inflated, abruptly dilated towards the throat, outside glabrous, inside with an annulus of simple hairs; tube incurved, 13 – 13 mm long, much exserted from the calyx; posterior lobe hood-like, obovate, 5 – 8 × 2 – 3 mm; anterior lobes spreading; median lobe with slightly bilobed apex; lateral lobes undulate. Staminal filaments fleshy, glabrescent. Disk lobed, tumescent behind. Style slender with equally lobed, cordate-like apex. Nutlets not seen. Fig. 3 .

RECOGNITION. Gomphostemma repentum is similar to G. dolichobotrys and G. microdon by having an unbranched, elongated, raceme-like inflorescence, but it is a climbing herb with curving stems. Additionally, G. dolichobotrys differs by its bracts that are smaller than the calyx, whereas the bracts exceed the calyx in G. repentum; and the inflorescence of G. microdon has lax opposite cymes with the axis visible between flowers whereas the inflorescence of G. repentum has congested opposite cymes with the axis not visible between flowers. Gomphostemma repentum is found in Northern Burma which neighbours the areas where G. microdon occurs in China and Laos: G. dolichobotrys is found in Sumatra, Indonesia.

DISTRIBUTION. Burma. Map 5 .

SPECIMENS EXAMINED. MYANMAR. Kayah. Upper Burma, Karenni [Kayah], Ywathit, Salween Valley, 600 m [2000 ft], 11 Jan. 1913, Micholitz s.n. (holotype K) .

HABITAT. On mountain, 600 m.

CONSERVATION STATUS. Gomphostemma repentum is known only from the type specimen. The Ywathit?am is a megahydropower-procect with 2,300 MW capacity on the Salween River which will affect the valley in which this species grows ( Salween Watch Coalition, 2016). Furthermore, extensive logging concessions have been granted around the procect site. Therefore, the Critically Endangered (CR) category is applied: CR B1ab(i,ii,iii) and B1ab(i,ii,iii).

PHENOLOGY. Flowering January.

ETYMOLOGY. The epithet repentum [ repens , creeping] refers to its habit.

Figures

Map 5. Distribution range of Gocphostecca leptodon, G. castersii, G. celissifoliuc and G. ovatuc.

Fig. 3. Gocphostecca repentuc. A habit; B stellate hair froc lower leaf surface; C upper leaf surface inducentuc showing 3- celled sicple hairs and 1-celled sicple hairs; D flower, lateral view; E calyx cut and opened to show ovary, style and stigca; F corolla cut and opened as flat as possible to show stacens and an annulus of sicple hairs; G sicple hairs froc the annulus. All froc Micholitz s.n. DRAWN;Y ANDREW;ROWN.