Gomphostemma flexuosum 3ongch

Bongcheewin, Bhanubong, Ingrouille, Martin J. & Paton, Alan J., 2022, A revision of Gomphostemma (Lamiaceae), Kew Bulletin 77 (1), pp. 27-92 : 53-54

12. Gomphostemma flexuosum 3ongch .

sp. nop. Type: Thailand, Chaiyaphum, Phu Khiew Wildlife Sanctuary, 10 km from Headquarters to main road, 800 m, 11 Oct. 1998, Suddee et al. 933 (holotype K [K001081922]; isotypes BKF, TC?).

http://www.ipni.org/urn:lsid:ipni.org:names:55221332-1

Sprawling herb. Stems slender, scrambling, obtusely quadrangular with shallowly longitudinal grooves, tomentose with stellate hairs; internodes of leafy and flowering shoots appearing wavy, always twisting. Leaoes petiolate or subsessile, spreading, chartaceous; blades elliptic, elliptic-ovate or oblanceolate, 3 – 13 × 2.3 – 8 cm, apex acute, margin serrate to subentire, base cuneate or attenuate, upper side scabrid with stiff hairs, lower side pale green tomentose with stellate hairs with a 1-celled stalk; petiole 3 – 20 mm long. Inflorescence axillary with opposite cymes sessile, unbranched then congested with axis not visible between flowers; verticils 2 – 10-flowered, inserted at the upper nodes at which leaves are usually present; bracts oblanceolate, 6 – 13 × 2 – 3 mm, with dense stellate hairs on both sides; bracteoles linear or sometimes falcate. Flowering calyx infundibular, 5 – 10 mm long, 10-ridged, outside with dense stellate hairs with a 1- celled stalk and dendroid hairs, inside with simple hairs; tube 3 – 2 mm long; lobes narrowly triangular, 2 – 6 mm long, apex acuminate. Fruiting calyx infundibular, 10 – 12 mm long; tube 2 – 3 mm long; lobes triangular, 6 – 5 mm long. Corolla white, 13 – 20 (– 23) mm long, throat inflated, abruptly dilated near the throat, outside with sessile stellate hairs, inside glabrous; tube slightly incurved, 12 – 15 mm long; posterior lobe shorter than anterior lobes, outside with sessile stellate hairs and glandular-like simple hairs, inside sparsely tomentose near throat; anterior lobes spreading; median lobes broadly ovate, 2 – 3 mm long, apex slightly emarginate; lateral lobes ovate. Staminal filaments fleshy, glabrescent. Disk lobed, slightly tumescent behind. Style slender with subequally lobed apex. Nutlets solitary, immature seen. Fig. 2 .

RECOGNITION. Gomphostemma flexuosum is recognised by having sprawling habit, flowering shoots appearing wavy with curving internodes, calyx lobes longer than the tube, short corolla, 13 – 20 (– 23) mm long and found in open and dry areas. It is morphologically similar to G. melissifolium by having an incurved corolla tube, coarse indumentum on the upper side of leaves and inflated corolla throat.

DISTRIBUTION. Vietnam, Laos, Thailand. Map 3 .

SPECIMENS EXAMINED. VIETNAM.?ong Nai: Langahn [Long Khanh], Station de Langanh,?u Haut?anai, 1000 – 1200 m, 3 Oct. 1932, Poilane 21030 (P). LAOS. Champasak: Mekong, Se?on, 1866 – 1868, Thorel 2221 (P 6 sheets).

THAILAND. Sakon Nakhon: Phu Phan National Park, 15°03&N 103°38&E, 220 m, 20 Oct. 1998, Suddee et al. 1012 (K); ibid., Chantaranothai et al. 528 (BKF); Chaiyaphum: Phu Khiew Wildlife Sanctuary, 10 km from Headquarters to main road, 800 m, 11 Oct. 1998, Suddee et al. 933 (holotype K; isotypes BKF, TC?); Nakhon Ratchasima: Pak Thong Chai, Sakaerat Forest Research Station, along Huai Krae Stream, 12°23&N 102°E, 200 m, 1 Nov. 1969, oan 3eusekom & Charoenpol 1992 (AAU, BKF, L); Ban Kaeng Khlo, 200 m, 15 Sept. 1951, Vidal 3118 (AAU, P); Buri Ram: Khao Phanom Rung, 12°32&N 102°36&E, 3 Oct. 1982, Murata et al. T-35323 (BKF); Saraburi: Muang, Sahm Lahn Forest, 130 m, 13?ec. 1953, Maxwell 53-533 (AAU, BK); Ban Nawng Bua [12.3880°, 100.5632°], 2 Oct. 1925, Put 1136 (BK, BM, GH, L, SING).

HABITAT. In dry dipterocarp, fire-influenced open forest; alt. 130 – 1200 m.

CONSERVATION STATUS. This species has been collected from several conservation areas in Thailand. Least Concern (LC).

PHENOLOGY. Flowering September –?ecember. NOTES. The epithet flexuosum [flexuosum, zigzag] refers to its wavy stem.

Figures

Map 3. Distribution range of Gocphostecca chinense, G. curtisii, G. flexuosuc, G. grandifloruc, G. hainanense and G. hirsutuc.

Fig. 2. Gocphostecca flexuosuc. A habit; B stellate hairs with a 1-celled stalk froc lower leaf surface; C upper leaf surface inducentuc; D flower, lateral view; E glandular hairs with a culti-celled stalk froc corolla; F stellate hairs with a 1-celled stalk; G dissected calyx showing the outer surface on one lobe and the inner surface on the four others; H dendroid hair with a culti-celled stalk and stellate hair with a 1-celled stalk froc calyx. All froc Suddee et al. 933. DRAWN;Y ANDREW;ROWN.