Zingiber jiewhoei Škorničk., 2014

Phathavong, K., 2014, Three new ginger species (Zingiberaceae) from Laos, Blumea 59 (2), pp. 106-112 : 110

Zingiber jiewhoei Škorničk. sp. nov. — Fig. 3

Similar to Zingiber peninsulare Theilade , but differs in cream-white labellum and cream-white staminodes with dense, bright, purple-violet blotches (vs labellum and staminodes dark purple with white spots). — Type: Jana Leong-Škorničková, Tr ần Hṹu Đăng, Somsanith Bouamanivong, Khantheo Santhammavong, Udone Souvannakhoummane, Kittisack Phoutthavong JLS-1807 (holotype SING (incl. spirit); isotype E, HNL), Laos, Vientiane Prov., Vang Vieng Dist., Kaeng Nyui waterfall, 370 m asl, N18°57'21.5" E102°29'45.5", 25 June 2012.

Etymology. We name this beautiful species in honour of Mr.Tan Jiew Hoe, President of the Singapore Gardening Society, for his continuous contribu- tions towards ginger research at Singapore Botanic Gardens and generous support of plant taxonomy in Laos.

Rhizomatous,clump-forming herb. Rhizome 1–3cm diam,branch- ed, 1–3 cm between leafy shoots arising from the same rhizome, externally pinkish (young rhizomes) to light brown (older rhizomes), internally purple, smelling strongly of lemongrass, scales broadly triangular, soon decaying. Leafy shoot to 2.5 m long, arching, with up to 42 leaves, base swollen to 3 cm diam, pink-red, basal 1/2 to 1/3 of pseudostem leafless, sheathed by numerous (c. 13) leafless sheaths; leafless sheaths dark green with faint, dark red-brown tinge towards base; leaf sheaths green, glabrous at base, pubescent towards the ligule; ligule to 9 mm long, shallowly bilobed, green, pubescent when young, glabrescent in old pseudostems; petiole reduced to a pulvinus (to 5 mm long); lamina to 30 × 8 cm (gradually smaller towards apex of leafy shoot), narrowly ovate (lanceolate), gradually tapering to attenuate apex, base rounded, adaxially glossy green, glabrous, abaxially lighter green and sparsely villose. Inflorescence radical, on erect peduncle to 16 cm long sheathed by 4–8 sterile bracts; spike 9–18 by 4–5 cm, fusiform, with up to 50 bracts; bracts obovate, to 4.7 by 2.7 cm (smaller towards apex of inflorescence), apex broadly acute, externally bright red, whitish towards base, internally whitish except red margins, glabrous and glossy both sides, enclosing a single flower; bracteole to 4 cm long, 15 mm broad at widest point, narrowly ovate, translucent white with apex tinged red, glabrous throughout. Flowers 7–9 cm long; calyx c. 21 mm long, translucent white, glabrous, with three inconspicuous, reddish teeth at apex, with unilateral incision c. 10 mm; floral tube c. 42 mm long, white towards base, cream-yellow towards apex, externally glabrous, internally shortly puberulous at apex; dorsal corolla lobe narrowly ovate-triangular, to 40 mm long, c. 11 mm broad at widest point, semi-translucent light yellow, glabrous throughout, apex mucronate, mucro <1 mm; lateral corolla lobes narrowly ovate-triangular, to 35 mm long, 5–6 mm broad at widest point, semi-translucent light yellow, glabrous throughout, apex acute; labellum c. 30 mm long, c. 16 mm wide (c. 28 mm including the staminodes), ovate, cream-white; lateral staminodes 16–20 mm long, c. 7 mm broad, more or less elliptic, connate to the labellum by basal 2/3, cream-white with dense bright purple-violet blotches. Stamen 25 mm long; filament reduced to <1 mm; anther c. 25 mm long (crest not straightened), c. 4 mm broad, connective tissue cream-white with pink tinge, glabrous; anther crest c. 20 mm long (straightened), wrapped around stigma, white, glabrous; anther thecae c. 14 mm long, dehiscing along their entire length. Epigynous glands 2, c. 5 mm long, c. 0.75 mm diam, ochraceous. Style white, glabrous; stigma 2–3 mm long, slightly thicker than style, white, ostiole facing downwards (towards the labellum), ciliate. Ovary 4.5 by 3 mm, white, glabrous, trilocular with central pla- centation. Fruit (young fruit, perhaps immature) ovoid or slightly trigonal capsule, 2.3 by 1.1 cm, white, glabrous; seeds c. 8 by 3 mm, dark maroon, enclosed in translucent white, irregularly laciniate aril. Description based on living and spirit material of Leong-Škorničková et al. JLS-1807.

Distribution — Currently known only from the type locality.

Habitat & Ecology — Growing near streams in lowland deciduous forest.

Phenology — Flowering in the early rainy season, June to July, flowers open in the afternoon, around 3 pm and close the next morning. Fruiting occurs at the end of June to August.

Conservation status — Specimen records exist so far only from the type locality. Accordingly, we conclude that the extent of occurrence is less than 20 000 km 2. The type locality is a popular tourist destination and the type population is not in a protected area, continuing decline in area, extent and quality of habitat can be foreseen. Category Vulnerable VU B1 a,b(iii) is therefore proposed here. Further exploration of the area around Vang Vieng is needed to understand the situation better and to amend the conservation status .

Notes — By its fusiform inflorescences and bright red bracts,

Z. jiewhoei resembles Z. peninsulare and Z. newmanii Theilade but it can be readily recognised by its cream-white labellum and cream-white staminodes with dense bright purple-violet blotches (vs labellum and staminodes with dense dark-maroon blotches).

Figures

Fig. 3 Zingiber jiewhoei Škorničk. a, b. Habit; c. detail of pulvinus and ligule; d. internal colour of rhizome; e. inflorescence; f. flower (side view); g. flower (front view); h. seeds; i. young fruit in bract; j. stamen (front and side view); k. fertile bract and flower with bracteole (side view); l. dissected flower (all from type: JLS-1807). — Scale bars: h, j = 1 cm; k, l = 2 cm. — Photos by Jana Leong-Škorničková.