Zingiber mellis 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 : 209-211

Zingiber mellis Škorničk., H.Đ.Tr ần & Šída f., sp. nov. (sect. Dymczewiczia)

Similar to Zingiber castaneum in having an upright inflorescence, but differs by its leafy shoots being composed of dark green leaves with short (c. 3 mm), thick, dark maroon, densely pilose ligules, spindle-shaped inflorescences with bracts tightly overlapping, honey scented flowers and an anther with almost reduced filament (compared to mid-green to bright green leaves, thin green glabrous ligules, inflorescence composed of strongly reflexed bracts, unscented flowers and anther with well-developed filament in Z. castaneum ).

Type: — VIETNAM. Kon Tum Province, Kon Plong Dist., Mãng Cành 14°44’25.2”N, 108°14’22.1”E, 1155 m, 20 July 2010, Trần H ữu Ðãng, Lê Công Kiệt, Nguyễn Duy Linh, Otakar Šída, Vũ Huy Đức 361 (holotype SING, isotypes E, VNM). Fig. 5 .

Rhizomatous herbs forming small clumps. Rhizome c. 1 cm in diam. Leafy shoot 0.6–1.0 m tall, with 5–12 leaves, basal 1/3–1/2 leafless; bladeless sheaths 4–6 leafless sheaths, green with dark red tinge towards base, pilose (denser in apical part and towards the margins); leaf sheaths dark green with maroon tinge at margins, sparsely pilose, denser towards margins; ligule c. 3 mm long, shallowly bilobed, maroon, densely pilose; petiole up to 5 mm long; lamina ovate to elliptic, up to 20 × 7 cm, apex attenuate to caudate, base rounded, dark glossy green above, lighter green beneath, fairly leathery in texture with no prominent plication, glabrous on upper side, finely hairy with silky long hairs beneath. Inflorescence terminal, in upright position; spike 5.0– 7.5 cm long, 1.5–2.0 cm broad, spindle shaped, consisting of 8–12 bracts; bracts obovate, up to 3.8 cm long and 2.8 cm broad (largest in the middle of the inflorescence), glossy green (turning through yellow to bright red with age), glabrous, with broadly acuminate apex; cincinnus of 2 flowers per bract (only 1 flower at uppermost bracts, lowermost 1–3 bracts sterile); bracteole obovate-triangular, 13–20 × 4–11 mm broad, unequally folded with one keel, translucent yellow, glabrous externally and internally. Flower 5–6 cm long, opening in the afternoon, emitting slight honey-like scent; calyx 7–9 mm long, translucent yellow, glabrous, with no conspicuous teeth at apex (appears truncate), with unilateral incision 2–4 mm; floral tube 24–38 mm, externally and internally yellow (lighter towards the base), glabrous externally, pubescent at apical part internally; dorsal corolla lobe narrowly ovate-triangular, 28–33 × 9–10 mm, semi-translucent yellow, glabrous externally and internally, apex mucronate, mucro less than 1 mm; lateral corolla lobes narrowly ovate-triangular, 28–30 × 6–7 mm, semi-translucent yellow, glabrous externally and internally, apex narrowly acute; labellum broadly trullate, c. 30 × 22 mm, dark maroon-brown, with minute yellow streaks, velvety appearance, flat (margins not reflexed); lateral staminodes narrowly unequally ovate, 15–17 × 6–7 mm, connate to labellum by 1 mm, yellow. Stamen c. 22 mm long (anther crest unmanipulated); filament c. 1 mm long, 2.0– 2.5 mm broad at base, yellow, glabrous; anther 27–30 mm long (with anther crest straightened), 3–4 mm broad, connective tissue yellow with dark maroon-brown tinge towards the anther crest, glabrous, anther crest 13–15 mm long, wrapped around stigma, heavily tinged dark-maroon-brown, glabrous; anther thecae c. 14 mm long, dehiscing along entire length; Epigynous glands two, 3–5 mm long, c. 1 mm diameter at base, cream-white. Ovary 3.0 × 2.5 mm, light yellow-greenish, glabrous, trilocular with central placentation. Style light yellow with red tinge in middle part, glabrous; stigma c. 2 mm long, slightly thicker than style, light yellow, ostiole front facing, shortly ciliate. Fruit and seeds not seen.

Etymology:— The epithet ‘ mellis ’ denotes the honey-scented flowers.

Distribution & IUCN preliminary assessment:— So far it is known only from the type collection in central Vietnam. Until more exploration of the region will be made, this species shall be considered as Data Deficient.

Ecology and phenology:— Growing in broadleaved evergreen montane forest at altitude about 1150 m. Flowering in June to July.

Figures

FIGURE 5. Zingiber mellis. A. Habit. B. Inflorescence. C. Flower (front view). D. Flower (side view). E. Detail of ligules (scale bar in mm). F. Flower dissection (from left): floral tube with ovary, calyx and anther (side view), dorsal and lateral corolla lobes and lateral staminodes, labellum, bracteole, and bract (scale bar in cm). G. Detail of anther (front view), ovary and epigynous glands (scale bar in mm). Photo: Jana Leong-Škorničková