Zingiber flavofusiforme M.M. Aung & Nob. Tanaka, 2017

Zingiber flavofusiforme M.M. Aung & Nob. Tanaka View in CoL , sp. nov.

(sect. Dymczewiczia ) ( Fig. 1 View FIGURE 1 , A–H)

Zingiber flavofusiforme is quite unique among the section and well characterized by its fusiform inflorescence with orange yellow bracts, small inconspicuous lateral staminodes, and pale yellow labellum with purple-red to maroon tinge and numerous pale yellow blotches.

Type:— MYANMAR. Sagaing Region: Nam Ei Mae, along the Nam Ei Zu River, branch of the Chindwin, Htamanthi Wildlife Sanctuary , Khamti Township, 120 m alt., 12 September 2016, Tanaka et al. MY850 (holotype TNS! , isotypes NY! , RAF! ).

Perennial rhizomatous herbs, ca. 1.2 m tall. Rhizomes to 2.5 cm in diam, horizontally elongate, branched, very short between leafy shoots, internally creamy white, externally dirty white, weakly aromatic. Leafy shoots up to 1.5 m tall, with 7–9 leaves, finely strigose, basal part of pseudostem ca. 1/3 leafless; bladeless sheaths 2–3, reddish green; ligules 6 mm long, shallowly bilobed, glabrescent; petiole inconspicuous, pulvinus, light green, glabrous; lamina narrowly ovate-lanceolate, 20–25 cm long, 5–5.5 cm wide, adaxially dark green, glabrous, prominently plicate, abaxially green, with weakly purple reddish, sparsely pubescent along the midrib, margin entire, base obtuse, apex attenuate. Inflorescences terminal on leafy shoots, in upright position, peduncle sessile; spikes narrowly ovate to ovoid, 12–14 cm long, 3.5 cm wide, consisting of 15–17 bracts (all bracts usually fertile); bracts orange yellow (turning yellow with age), ovate, ca. 3.7 cm long, ca. 2.5 cm wide, apex rounded, glabrous, subtending 1-flower; bracteoles 3 cm long, 1 cm wide. Flowers 7 cm long; calyx ca. 2 cm long, translucent white, glabrous, with one or two teeth at apex; floral tube slender, 3.5–4 cm long, 0.3 cm in diam., externally and internally creamy white, externally glabrous, internally puberulent; corolla lobes pale yellow; dorsal corolla lobe ovate, ca. 2.5 cm long, ca. 0.9 cm wide, curved, cream yellow with translucent margin; lateral corolla lobes narrowly ovate, ca. 2.5 cm long, 0.7 cm wide, the same colour as the dorsal lobe; labellum broadly obovate to rhomboid, 2.5 cm long, 2 cm wide at the widest position, basally pale yellow, with radical pale yellow streaks from the base, and purple-red to maroon tinge and numerous pale yellow blotches, glabrous, margin undulate, apex shallowly trilobed; lateral staminodes inconspicuous, filiform, 4 mm long, cream yellow, connate to labellum basally. Anther yellow, ca. 2.8 cm long with a crest, anther crest ca. 1.4 cm long, wrapped around stigma; thecae 1.3 cm long, parallel, dehiscing along the entire length. Style white, 2.5 cm long, filiform, glabrous, stigma white, ciliate. Epigynous glands two, ca. 5 mm long, linear, pale yellow. Ovary ca. 4 mm long, 2 mm wide, white, trilocular with many ovules on axile placenta, densely pubescent. Mature fruits not observed.

Etymology:—The specific epithet refers to yellow to orange fusiform shape of the inflorescence.

Distribution:—So far known only from the type collection in Htamanthi Wildlife Sanctuary, Sagaing Region, Myanmar.

Phenology:—Flowering from August to September. Fruiting period unknown. The flowers open in the morning.

Other specimens examined:— MYANMAR. Sagaing Region: Homalin Township, basin of the Chindwin River, along the Nan-Ba-Gon stream, Nan-Ba-Gon area, Htamanthi Wildlife Sanctuary , 120 m alt., 25°121’ N, 95°25’ E, 24 October 2014, Mu Mu Aung et al. 073 ( RAF, TNS-sterile) ; along the Nankhawedaing stream, Nankhawedaing area, Htamanthi Wildlife Sanctuary , 180 m alt., 25°19’N, 95°28’E, 24 October 2014, Mu Mu Aung et al. 079 ( RAF, TNSsterile) GoogleMaps .