Amomum meghalayense V.P.Thomas, M.Sabu & Sanoj, 2016

Thomas, V. P., Sabu, M. & Sanoj, E., 2016, Amomum meghalayense (Zingiberaceae): a new species from northeast India, Phytotaxa 245 (2), pp. 178-182 : 178-181

Amomum meghalayense V.P.Thomas, M.Sabu & Sanoj , sp. nov. ( Figs 1 , 2 )

Amomo hypoleuco similis in floribus majoribus centro macula lutea et rubra instructa, sed differt rhizomis non-stoloniferis, foliis lanceolatis infra dilute viridis, apice tenuiter circinali, inflorescentia solitaria a rhizoma sub caule orienti, bracteis 2 vel 3 floribus gaudentibus, et antherae basi appendice alato.

A species similar to A. hypoleucum in having large, white coloured flowers, but differs from this species in having non-stoloniferous rhizomes, linear lanceolate leaves with finely coiled apices, flowers in cincinii of two or three and the anther having basal wings.

Type:— INDIA. Meghalaya: West Garo Hills District, Tura Peak, 6 August 2007, E. Sanoj & T. Rajesh Kumar 95123 (holotype CALI!, isotype ASSAM!).

Rhizomes non-stoloniferous, 1.0– 1.2 cm thick, length/width ratio c. 2:1, creamy-white inside. Leafy shoots 50–100 cm, slanting, clump-forming; sheath c. 1 cm wide at base, green, margin membranous, puberulous externally. Leaves 5–9 per shoot, slender, clumping; laminae linear-lanceolate, 16–30 × 2.0– 3.2 cm, aromatic when crushed, dark green above, pale beneath, bases cuneate, margins glabrous, apices acuminate to 5 cm long, coiled, glabrous on both surfaces; midribs glabrous; veins slightly raised above; petioles absent or to 1.7 cm, green, glabrous. Ligules 0.3–0.4 cm, coriaceous, margins ciliate, apices truncate to emarginate, glabrous. Inflorescences c. 3 cm, arising from the rhizome just below the aerial stem, 3–5 flowered; peduncle 1–2 cm. Outer bracts linear lanceolate, c. 3.7 × 0.7 cm, coriaceous, not deciduous, green, margins ciliate, apices acute, pubescent externally, rarely puberulous internally; inner bracts oblong or linear, 4.5–4.7 × 1.0– 1.1 cm, chartaceous, red, margins glabrous, apices rounded, pubescent externally, each bract subtending 2–3 flowers. Bracteoles non-tubular, size reduced towards inner flower, c. 0.6 × 0.1 cm, white, membranous, margins ciliate, cuspidate at apex, pubescent externally, glabrous internally. Flowers 5.2–6.0 cm, white, in cincinii of 2 or 3. Calyx bilobed, 1.8–1.9 × 0.35–0.40 cm, pale pink, split or less equally, cleft c. 0.4 cm deep, two curled pubescent horns present behind apex back, pubescent externally, glabrous internally. Corolla tubes 1.8–1.9 × c. 0.5 cm at mouth, white, pubescent towards mouth and puberulous towards base externally, villous towards mouth, glabrous towards base within; dorsal corolla lobe oblanceolate, 2.3–2.4 × 0.9–1.0 cm, white, margin ciliate, apex hooded with a 0.1–0.2 cm pubescent cusp, glabrous on both surfaces; lateral corolla lobes lanceolate, c. 2.1 × 0.8 cm, margins ciliate, one side slightly folded at apex, glabrous on both surfaces. Labellum obovate, entire, 3.4–3.5 × 2.4–2.5 cm, white towards periphery, red and yellow patch at centre, margins crumbled, slightly crenulate, pubescent towards base internally. Lateral staminodes usually absent. Stamen 1.8–1.9 cm; filament 0.8–0.9 × 0.25–0.30 cm, white, a channel present that holds the filament in position, glabrous; connective winged at base of thecae, puberulous; crest trilobed, 0.60–0.65 × c. 0.3 cm, white, apex slightly lobed; anther thecae oblong, 0.6–0.7 cm, creamy-white, base rounded, apex rounded, glabrous; dehiscing throughout their length. Epigynous glands 2, oblong, 0.30–0.35 cm long, creamy-white, apex minutely lobed, rarely puberulous externally. Ovary barrel shaped, 0.4–0.5 × 0.3–0.4 cm, slightly angled, pubescent externally; locules 3; ovules many on axile placentae; style c. 3.6 cm long, glabrous; stigma cup-shaped, c. 0.1 cm, red spotted, mouth ciliate, opening terminal. Infructescence c. 3 cm long, 1–2 capsules per spike; peduncle c. 1.5 cm long. Capsule globose, 8–9 ribbed, 1.5–20 × 1.5 cm, dark maroon, pubescent externally, calyx not persistent. Seeds many, angular, c. 0.3–0.4 cm, black, aromatic, arillate; aril white. Flowering and fruiting from May to August.

Etymology:—Named for the Indian state of Meghalaya where the species occurs.

Ecology:—Growing in evergreen forests at high elevation.

Additional Specimen examined (paratype):— INDIA. Meghalaya: Rongal Ading Forest (Baiza), 4 May 1997, S. Tripathi 20819 (CDRI).

Figures

FIGURE 1. Amomum meghalayense. A. habit. B. ligule. C. inflorescence. D. bract. E. bracteole. F. flower. G. calyx. H. corolla lobes. I. stamen. J. labellum. K. ovary with epigynous glands and style. L. stigma. M. c.s. of ovary. N. fruit. O. seed.

FIGURE 2. Amomum meghalayense. A. habit. B. ligule. C. inflorescence. D. rhizome. E. bract. F. bracteole. G. & H. flowers. I. calyx. J. corolla lobes. K. labellum. L. stamen. M. anther crest. N. anther base with appendage. O. epigynous glands and style. P. stigma.