Gomphostemma sulcatum C.Y. Wu (1963: 129)

Bongcheewin, Bhanubong, Ingrouille, Martin J. & Paton, Alan J., 2022, A revision of Gomphostemma (Lamiaceae), Kew Bulletin 77 (1), pp. 27-92 : 69

22. Gomphostemma sulcatum C.Y. Wu (1963: 129) ;

Li & Hedge (1992: 52).

Type: China, Yunnan, Ping-bien, 8?ec. 1932 [22 Aug. 1932], Tsai 61603 (holotype PE; isotypes A n.v., IBSC).

Perennial herb up to 1 m tall. Stems erect, obtusely quadrangular with longitudinal grooves, tomentose with dense stellate hairs with a 1-celled stalk, dendroid hairs absent. Leaoes petiolate, chartaceous; blades elliptic or elliptic-ovate, 18 – 28 × 5 – 13 cm, apex acute, margin shallowly serrate, base attenuate, upper side tomentose with 1 – 2 (– 3)-celled simple hairs, lower side pale green tomentose with dense stellate hairs; petioles 20 – 30 mm long. Inflorescence axillary with opposite cymes sessile, unbranched then congested with axis not visible between flowers, inserted at the upper nodes at which leaves are usually present; verticils many-flowered, subtended by the upper leaves and cluster of small leaf-like bracts; bracts leaf-like, ovate, 20 – 30 × 8 – 13 mm, apex acute, margin shallowly serrate, base obtuse, upper side dark green with 1 – 2 (– 3)-celled hairs, lower side pale green with dense stellate hairs; bracts narrowly lanceolate, linear or falcate, 3 – 20 mm long. Flowering calyx tubularinfundibular, 9 – 12 mm long, 10-ridged with veinlets at each sinus; tube 3 – 8 mm long, outside dense tomentose with short simple hairs, inside glabrous; lobes triangular, 2 – 6 mm long, apex acuminate, with stellate hairs on both sides. Fruiting calyx not seen. Corolla yellow, 30 – 20 mm long, throat inflated, abruptly dilated near the throat, outside tomentose, inside glabrous; tube slender, slightly incurved, 23 – 33 mm long; posterior lip ovate, 3 – 6 mm long, apex and margin undulate; anterior lip 3- lobed, spreading beyond posterior lip; median lobe obcordate, base constricted; lateral lobes with round apex. Staminal filaments fleshy, tomentose at apex. Style slender, glabrous, inclined under posterior lip with apex subequally lobed. Nutlets not seen.

DISTRIBUTION. China (Yunnan). Map 6 .

SPECIMENS EXAMINED. CHINA. Yunnan. Ping-pien Hsien [22.9°, 103.6665°], 1100 m, 22 Aug. 1932, Tsai 61603 (holotype PE, isotype IBSC).

HABITAT. In hill evergreen forest, 1100 m.

CONSERVATION STATUS. Gomphostemma sulcatum is known only from the type. Hence, the?ata?eficient (??) category is applied to this species.

PHENOLOGY. Flowering August.

NOTES. Gomphostemma sulcatum is a distinctive species defined by having a corolla much exserted from the flowering calyx and the calyx glabrous inside. It is morphologically similar to G. nioeum by having a cluster of small leaf-like bracts exceeding the calyx and congested cymes. This species is found close to the border between China and Vietnam. This species may be present in Vietnam as well but further botanical collection in Northern Vietnam is needed to confirm this.

Figures

Map 6. Distribution range of Gocphostecca stellatohirsutuc, G. sulcatuc, G. velutinuc and G. cicrocalyx.