Zingiber microcheilum Škorničk., H.Đ.Tr

Leong-Škorničková, Jana, Bình, Nguy ễn Qu ốc, Đăng, Tr ần H ữu, Šída, Otakar, Rybková, Romana & Vương, Trương Bá, 2015, Nine new Zingiber species (Zingiberaceae) from Vietnam, Phytotaxa 219 (3), pp. 201-220 : 215-217

publication ID	https://doi.org/ 10.11646/phytotaxa.219.3.1
persistent identifier	https://treatment.plazi.org/id/CF4587D5-FF9D-FFBE-BCC3-FB139656FE76
treatment provided by	Felipe
scientific name	Zingiber microcheilum Škorničk., H.Đ.Tr
status

Treatment

Zingiber microcheilum Škorničk., H.Đ.Tr View in CoL ần & Šída f., sp. nov. (sect. Zingiber )

Similar to Zingiber officinalis L. in the shape and colour of the inflorescence, but markedly different in its very small labellum, a unique character in the genus.

Type: — VIETNAM. Quảng Nam Province, PhƯớc SƠn District, PhƯớc M ỹ, 15º18’00.8”N, 107º43’44.1”E, 686 m, 22 July 2010, Trần H ữu Ðãng, Lê Công Kiệt, Nguyễn Duy Linh, Otakar Šída, Vũ Huy Đức 382 (holotype SING, isotypes PR, VNM). Fig. 8 View FIGURE 8 .

Rhizomatous herbs. Rhizome branched, externally light brown, internally dirty yellowish to ochraceous. Leafy shoot to 0.8 m tall, slightly arching, with up to 10 leaves, basal third of pseduostem leafless or with remnants of leaves; bladeless sheaths and leaf sheaths green, pubescent; ligule up to 10 mm long, ovate, thin, pubescent; petiole 2–3 mm long, consisting of pulvinus only; lamina elliptic, 15–35 × 3–5 cm, apex narrowly acute to narrowly attenuate, base obtuse, green above, somewhat smooth (no prominent plication), light green, with sparse silky hair beneath. Inflorescence radical, erect; peduncle up to 3–15 cm, with c. 6 sheathing bracts; spike spindle-shaped, to 11 × 3.5 cm, consisting of 15–45 bracts; bracts ovate, c. 2.8 × 2.1 cm (gradually smaller towards the apical part of inflorescence), concave, bright green with white margin, glabrous externally and internally, apex obtuse; 1 flower per bract; bracteole obovate, c. 23 × 13 mm long, greenish, glabrous externally and internally. Flower 5.0– 5.5 cm long; calyx c. 12 m long, translucent white, glabrous, with unilateral incision to 7 mm, apex truncate; floral tube c. 30 mm long, white, externally and internally glabrous; dorsal corolla lobe triangular-ovate, 16–18 × 7–8 mm, semi-translucent light yellow, glabrous externally and internally, apex acute, concave, minutely hooded; lateral corolla lobes narrowly triangular-ovate, reflexed, c. 18 × 4 mm, semi-translucent light yellow, glabrous externally and internally, apex acute; labellum elliptic, 5–7 × 3–4 mm, light yellow with rich bright red tinge; lateral staminodes linear, 2–3 × 1 mm, light yellow. Stamen c. 13 mm long (unmanipulated); filament reduced; anther 14 mm long (with straightened crest), c. 3 mm broad, connective tissue cream-white, glabrous, anther crest 5–6 mm, wrapped around stigma, bright yellow, glabrous; anther thecae c. 8 mm long, dehiscing along the entire length. Epigynous glands two, 2–3 mm long, c. 0.6 mm in diam. at base, cream-white. Ovary obovate, c. 3.5 × 3.0 mm, cream-white, glabrous, trilocular with central placentation; style white, glabrous, stigma slightly thicker than style, white, ostiole front facing, ciliate. Fruit and seeds not seen.

Etymology:— The specific epithet reflects the much reduced labellum, which is smallest in the genus and the most striking feature of this interesting species.

Distribution & IUCN preliminary assessment:— So far known only from the type locality.

Ecology and phenology:— On steep slopes in lower montane semi-deciduous forest around 600– 700 m. Flowering occurs in July to August.

Based on morphology, Zingiber microcheilum seem to be related to the best known member of the family, the ginger of commerce, Zingiber officinale . The shape and colour of the inflorescence is somewhat similar, but the striking difference lies in the size and shape of the much reduced labellum, which is yellow with a reddish tinge throughout, while Zingiber officinale has a well developed dark red to maroon labellum with yellowish speckles. The small size of the labellum in Z. microcheilum is unique in the genus Zingiber .