Zingiber pherimaense Biseshwori & Bipin 2014, sp. nov.

Abstract

Zingiber pherimaense Biseshwori & Bipin, sp. nov. (Fig. 1) Zingiberi meghalayensi similis, planta breviore ca. 1.5—2 m, laminis brevioribus ca. 33–36 cm longis, 6.8–7.2 cm latis, pedunculis longioribus ad 10−13 cm longis, labelli ordinatione magentea apice lato rotundato differt. Type:— INDIA. Bipin K. IBSD /Z- 105, cultivated at IBSD, Imphal, Manipur, India (Holotype ASSAM, isotype IBSD). Originally from India, Nagaland, Pherima, ca. 870 masl, 25º45.426’N 93º57.223’E, 4 August 2012, cultivated as IBSD /Z-105. (Fig. 1) Terrestrial herb up to 2.0 m tall; rhizome subsurface, multiple, compact, vertical sections each ca. 2 cm diam., externally tan-white, internally with two-concentric rings, inner ca. 15 mm diam., outer 3 mm wide, both light yellow, numerous adventitious roots on the vertical sections, rhizome underside with fleshy, tuberous roots without a terminal swelling. Leafy shoots or pseudostems erect, thick, ca. 2−2.5 cm diam., leafless sheaths greenish-red, pubescent. Leaves 20−22, distichous; petiole sessile, pubescent; ligule ca. 5 mm long, bilobed, apices rounded, light green with some red, pubescent; lamina oblong-lanceolate, 33−36 × 6.8−7.2 cm, base cuneate, apex acuminate, glabrous above, pubescent beneath. Inflorescence radical, decumbent, peduncle ca. 10−13 cm long, 0.9 cm diam., sheaths five, obovate, reddish, glabrous; spike capitate, flat topped, 2−3 x 5−7 cm. Bracts cymbiform, loosely imbricate, numerous, 4 × 0.4 cm, apices rounded, red, sparsely pubescent; bracteoles linear-lanceolate, 3 × 0.4 cm, reddish, pubescent. Flowers 6−6.5 cm long; calyx tubular, 1 × 0.4 cm, partially split one side, tri-dentate, transparent white, apices sparsely pubescent. Corolla tube slender, 3 cm long, white, sparsely pubescent externally; corolla lobes subequal, white at the base, pink towards the apex, dorsal lobe lanceolate, 3−3.5 × 0.5 cm, apex acute, arching over the anther; lateral lobes lanceolate, 2−2.6 × 0.5 cm, apex acute, extending beyond the labellum. Labellum 3-lobed, ca. 3.8 x 0.5 cm, rectangular, slightly concave above the throat, flattening toward the apex, broadening upward to the sidelobes, midlobe ca. 1.5 × 1 cm, rectangular, white with magenta (RHS 72 B) longitudinal lines and markings, apex rounded to emarginate, margins slightly undulate, irregular, sidelobes ca. 5 × 5 mm, white with magenta markings, apices slightly acute, reflexed. Stamen ca. 1.4 cm long, white with magenta stripes on the upper surface, filament ca. 2 × 2 mm, white, thecae parallel, ca. 6 mm long, ca. 1.5 mm wide (each), creamy-white, anther crest elongate, beaked, ca. 6 mm long, 1.5 mm wide at the base, pollen creamy-white. Ovary globose, trilocular, 3 x 5 mm, villous with soft, brown hairs, style filiform, white, stigma white, ostiole circular with stiff hairs on the perimeter; epigynous glands 2, linear, 7 mm long, apices acute, creamy-white. Fruit unknown. (Measurements based on living, cultivated material of Bipin K. IBSD /Z-105). Distribution: —Known only from the type locality. Ecology: —This species was found growing in a dense and tall bamboo thicket at ca. 870 m. along the margin of mixed evergreen forest on loose, grey-brown clay soils covered with humus and leaf litter. Rainfall in this area is 1800−2500 mm /year. The plant is dormant (without stems or leaves) from December to March during the cool, dry season. Etymology: —Named for Pherima village, Nagaland where it was first found in the nearby forest. Phenology: —Flowers occur from July through August, opening in the evening and senescing within 24 hours. Conservation status: —Unknown at this time. Notes: —Although its vegetative morphology has some similarity to Z. meghalayense, Z. rubens, Z. roseum and others, the very long peduncle, labellum shape and colour, and tightly clumping rhizomatous growth make it distinct. Labellum colour in each Zingiber species genetically follows a narrow colour palette with few known exceptions, e.g., Z. pseudopungens R.M. Sm. (1989: 413). Even populations in different geographic regions are only slightly variable in colour (tint, shade, tone, intensity) and/or pattern, but not to the extent of having a totally different colour scheme from the type. For instance, different populations of Z. rubens observed in India and Burma always have a labellum with a creamy-white and yellow background and a distinct, overlaid, swirled pattern of dark red or orange-red (Kumar et al. 2013). When labellum shape is considered, the sidelobes are of key diagnostic importance based on their shape, size and relative position to the midlobe. Species such as Z. ligulatum Roxburgh (1810:348), Z. roseum and Z. rubens have very small sidelobes situated at the base of the midlobe. Often these are difficult to see without flattening the labellum. In contrast, species such as Z. capitatum Roxburgh (1810:348), Z. intermedium, Z. meghalayense (2013:61), Z. nimmonii (J. Graham) Dalzell (1852:341) and the new species, have larger, distinct sidelobes originating at the midlobe base, but extending much further up the labellum. Another character which helps to distinguish this species is the width and shape of the midlobe apex. The two common shapes are acute, as in Z. meghalayense and Z. rubens, or rounded to truncate with an emarginate apex as in Z. intermedium, Z. roseum and the new species. The subterranean morphology, Z. pherimaense can be considered a tight clumper due to the very short, lateral rhizomatous growth. Here the rhizomes are more vertically developed with each successive growth element formed at the base of the previous growth, resulting in only a few stems in a very small perimeter. This growth is distinct from Z. rubens which has a semi-running rhizome, resulting in more widely spaced stems.Published as part of Thongam, Biseshwori & Konsam, Bipin, 2014, A new species of Zingiber (Zingiberaceae) from Nagaland, India, pp. 221-224 in Phytotaxa 178 (3) on pages 221-223, DOI: 10.11646/phytotaxa.178.3.9, http://zenodo.org/record/514549