Zingiber lecongkietii 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 : 202-204

Zingiber lecongkietii Škorničk. & H.Đ.Tr ần, sp. nov. (sect. Cryptanthium )

Similar to Zingiber emeiense Z.Y.Zhu in having purple-white flowers, but differs in the narrowly ovate to narrowly elliptic leaves (15–20 × 3.5–4 cm), short ligules (c. 1–2 mm, shallowly bilobed), pure white corolla lobes, purple to dark violet labellum with white blotches and pure white lateral staminodes (vs. laminae 25–35 × 6–9 cm; ligules papery, bifid, c. 7 mm long; red corolla lobes, and both labellum and lateral staminodes purple).

Type: — VIETNAM. Kon Tum Province, Kon Plong Dist., Xã Hiếu, 1237 m, 14°39’01.3”N, 108°24’38.5”E, 25 April 2012, Jana Leong-Škorničková, Nguy ễn Quốc Bình, Trần H ữu Đăng, Eliška Záveská JLS-1572 (holotype SING, isotypes E, P, PR, VNMN). Fig. 1 .

Rhizomatous herbs up to 1 m tall, forming small clumps. Rhizome sparsely branched, somewhat creeping, c. 1 cm in diam., externally cream to light brown, internally cream-white covered with brown papery triangular scales. Leafy shoot slightly arching, with up to 20 leaves, basal 1/3 of pseudostem leafless; bladeless sheaths 4–6, green with dark red tinge, puberulous, especially towards margins; leaf sheaths green, glabrous, margins puberulous; ligule 1–2 mm long, shallowly bilobed, pubescent; petiole up to 12 mm, light green, glabrous; lamina 15–20 × 3.5–4.0 cm, narrowly ovate, apex attenuate, base obtuse to rounded, dark green glossy above, smooth (no prominent plication), glabrous, slightly lighter green beneath, glabrous. Inflorescence radical, c. 15 cm long; peduncle subterranean or procumbent, up to 10 cm long, covered by sheathing bracts, white or with red tinge, puberulous; spike ovate to obovate, c. 5 × 2–3 cm, consisting of 10–20 bracts; bracts ovate, c. 3.0 × 1.5 cm (smaller towards the apical part of inflorescence), dark red-brown, puberulous, apex acute to narrowly acute, enclosing single flower; bracteole c. 25 × 12 mm, ovate, semi-translucent white at base, red-brown towards apex, puberulous to villous externally, glabrous internally. Flowers c. 6 cm long; calyx c. 10 mm long, with unilateral incision c. 8 mm, semi-translucent white, puberulous, apex with three small teeth; floral tube c. 32 mm, externally and internally white, puberulous externally, internally puberulous at base, puberulent towards the apical part; dorsal corolla lobe triangular-ovate, c. 25 × 10 mm, pure white with semi-translucent veins, sparsely puberulous externally, glabrous internally, apex acute, concave, slightly hooded; lateral corolla lobes narrowly triangular-ovate, 21 × 5–6 mm broad, pure white with semi-translucent veins, sparsely puberulous externally, glabrous internally, apex acute, concave; labellum broadly obovate, c. 26 × 20 mm (c. 30 mm broad inclusive lateral staminodes) purple to dark violet with white blotches; lateral staminodes obovate, 17 × 7 mm, pure white, connate to labellum by basal 1/2–1/3; stamen c. 20 mm long (unmanipulated); filament 2.0 × 2.5 mm, pure white, with sparse short glandular hairs; anther 22 mm long (with straightened crest), c. 4 mm broad, connective tissue white, glabrous, anther crest up to 12 mm, wrapped around stigma, purple, glabrous; anther thecae 10–11 mm long, dehiscing along the entire length. Epigynous glands two, 4–5 mm long, c. 0.6 mm in diam at base, ochraceous, apex acute. Ovary 6.0 × 2.5–3.0 mm, cream-white, puberulous, trilocular with central placentation. Style white, glabrous, stigma slightly thicker than style, white, ostiole front facing, ciliate. Fruit not seen.

Etymology:— We dedicate this species to Prof. Lê Công Kiệt for his life-long contributions to Vietnamese botany.

Distribution & IUCN preliminary assessment:— So far known only from the type locality in central Vietnam. Only two populations have been seen by us, but the species is expected to be found in adjacent areas as suitable habitat still seems to exist. Until further collections, this species should be treated as Data Deficient.

Ecology and phenology:— Occurring on the ridges in broadleaved evergreen montane forest around 1200 m. Flowering in April to May.

Additional specimens examined (paratypes):— VIETNAM. Kon Tum Province, Kon Plong Dist., Xã Hiếu, 1213 m, 14°40’59.4”N, 108°22’38.3”E, 26 April 2012, Jana Leong-Škorničková, Nguy ễn Quốc Bình, Trần Hữu Đăng, Eliška Záveská JLS-1575 (SING, VNMN)

Zingiber lecongkietii belongs to sect. Cryptanthium and can be easily recognized by its pure white flowers with dark purple to violet labellum—a colour combination not known from any other Zingiber species in Vietnam.

Figures

FIGURE 1. Zingiber lecongkietii. A. Habit. B. Pseudostem and detail of ligules (front and back view). C. Inflorescence (side view). D. Inflorescence (top view). E. Flower (front view). F. Detail of ovary with epigynous glands and anther (side and front view; scale bar in mm). G. Dissection (from left): corolla lobes and labellum, floral tube with anther in side view, calyx, ovary with epigynous glands, bracteole, bract (scale bar in cm). Photo: Jana Leong-Škorničková.