Zingiber magang

Zingiber magang N.S.Lý & Škorničk., Taiwania 66(2): 232‒240, 2021

Zingiber magang N.S.Lý & Škorničk., Photo by Hoang Thanh Son   

Its native range is Vietnam.

Vietnamese name: 

Gừng mangang

Latin Name: 

Zingiber magang N.S.Lý & Škorničk.

Synonym Name: 

No

Etymology:

The specific epithet “magang” is derived from the common name applied to this species by local people from Kinh tribe in Quảng Ngãi province. 

Family: 

Zingiberaceae

Description: 

Rhizomatous herbs 15–40 cm tall forming small loose clumps each with 2–7 leafy shoots. Rhizome loosely branched, 0.8–1.1 cm in diam., externally light brown, internally yellowish, slightly aromatic, covered with triangular, light brown, glabrous scales 2–3 cm long, soon decaying; root tubers formed at the end of roots, subglobose to ellipsoid, 1.4–2 × 0.5–1.2 cm, pale brown externally, cream-white internally. Leafy shoots 2–6 cm apart, swollen at base ca. 2 cm in diam., each shoot comprising of 3–5 leaves at maturity, positioned at apical part of the pseudostem; bladeless sheaths 3–4, 2.5–18 cm long, inconspicuously longitudinally striate, light green, outer ones with reddish tinge at base, glabrous; leaf sheaths inconspicuously longitudinally striate, light green, glabrous; ligule bilobed, 2–5 mm long, light green, glabrous or sparsely puberulous, apex acute, margins rusty brown; petiole 3– 7.7(–10.5) cm long, light green, pulvinus inconspicuous, positioned at the base of petiole, green, slightly pubescent to glabrescent; lamina broadly elliptic, (12.5–)19.5– 26.5(–31.4) × (6.5–)8.5–13(–16) cm, leathery, weakly plicate, adaxially dark green, shiny, glabrous, abaxially light green, semi-matt, glabrous, apex attenuate to acuminate, base obtuse with narrow wing-like leaf margins gradually extending along the petiole/pulvinus. Inflorescences 1–2 per clump, arising near the base of the pseudostem, 15–26 cm long, with 1–2 flowers open at a time; peduncle partly or fully embedded in ground, 5–11 cm long, 0.4–0.5 cm in diam., covered by 5–10 sheathing bracts, broadly triangular-ovate at base, ovate distally, white with red tinge, externally sparsely pubescent; spike narrowly ovoid to oblong, 7 –14 × 1.8–2.5 cm, consisting of up to 15 strongly imbricate fertile bracts, each subtending a single flower; bracts narrowly ovate, 3.5– 4.5 × 1–1.9 cm (gradually narrower towards apical part of the inflorescence), basal bracts greenish at base rest with rich red to purple tinge, apices in upper bracts greenish, externally densely pubescent, internally glabrous, margins straight (not undulated), pubescent, apex narrowly acute; bracteoles narrowly ovate, 26–32 × 15– 20 mm, greenish, sometimes with purple tinge at apex, externally sparsely pubescent, internally glabrous, apex acute. Flowers exserted from bracts, 6.2–7.5 cm long; calyx tubular, clasping the floral tube at base, 10–10.5 mm long, white, externally puberulous, with unilateral incision 4.5–5.5 mm long, apex with three blunt teeth (ca. 2 × 2 mm); floral tube 33–37 mm long, narrowly cylindrical, slightly widening distally (to ca. 3.5 mm in diam.), white, externally glabrous, internally with few hair near the throat; dorsal corolla lobe triangular-ovate, 22–24 × 7.5–8 mm, cream-white with semi-translucent veins, glabrous, apex narrowly acute with a short mucro ca. 1.5 mm long; lateral corolla lobes narrowly triangular-ovate, 21–22 × 4–5 mm, cream white with semi-translucent veins, glabrous, apex narrowly acute; labellum obovate, 23–25 mm long, 15–16 mm at widest point near the middle of labellum (18.5–21 mm broad inclusive of lateral staminodes), cream-white at basal 1/3, distally dark purple to purple-violet in the centre, gradually changing to pale purple or almost white slightly deflexed margins, glabrous, apex bifid, with incision of 5–6 mm long; lateral staminodes obovate, 15–15.7 × 3– 4.5 mm, cream-white to very pale yellow with semi- translucent veins, connate to labellum 1/2–1/3, glabrous, apex rounded to obtuse; stamen 19–19.5 mm long (unmanipulated); filament ca. 1 mm long, 2–2.5 mm wide, cream-white, glabrous; anther 11.5–12 mm long (crest not straightened), 3.5–4 mm broad, connective tissue cream-white to pale yellow, glabrous, anther thecae 10.5– 11 mm long, dehiscing along the entire length, pollen cream white, elliptic; anther crest 9.5–11 mm (straightened), cream with pink to red-purple tinge towards apex, glabrous. Epigynous glands two, subulate, 5–5.5 mm long, ca. 0.5 mm in diam. at base, cream sometimes with slight purple tinge. Ovary cylindrical, 4– 5.2 × 3–3.5 mm, pale greenish to cream white with purple tinge, pubescent, trilocular with axile placentation; style white, glabrous; stigma slightly thicker than style, white, ostiole ciliate. Fruit (immature) ovoid, bluntly trigonous septifragal capsule, 22–26 × 8–11 mm, cream-white with longitudinal reddish lines along the valves, glabrous, apex with persistent calyx. Seeds (immature) 4–6 per locule, oblong, 8–9.5 × 3.5–4 mm long, white; aril sac-like, irregularly edged/laciniate at apex, white, nearly fully covering the seeds.

Flowers: 

Apr-May

Distribution: 

Vietnam (Quảng Ngãi and Kon Tum).

Ecological: 

Stream sides and moist and shady areas of primary and secondary tropical broadleaved forests between 850–1,230 m elevation. Flowering was observed from June to August, fruiting was observed in August and September, but presumably extends till October.

Chemical constituents and Pharmacology:

Uses:

This species is locally known as magang (Kinh minority), Pagieng or Pagang (Co, Ca Dong and Hre minorities). Rhizomes of this species are harvested, crushed and applied for healing.

Typus:

VIETNAM. Quảng Ngãi Province: Ba Tơ District, Ba Nam Commune, Tây Ba Tơ protection forest, subzone 451, Cao stream, 14°37′49.08′′N, 108°37′10.20′′E, 962 m, 7 August 2019, Lý Ngọc Sâm, Trương Bá Vương, Cao Ngọc Giang, Lý-1327 (holotype VNM; isotypes: P, SING).

References

Ngọc-Sâm LÝ, Đăng-Giáp ĐỖ, Ngọc-Giang CAO, Bá-Vương TRƯƠNG, Văn-Thành NGUYỄN, Jana LEONG-ŠKORNIČKOVÁ, Zingiber magang and Z. tamii (Zingiberaceae), two new species from central Vietnam, Taiwania 66(2): 232‒240, 2021 DOI: 10.6165/tai.2021.66.232