Volume 16 > Part 2 > Year 2023 > Page 364 > Zingiberaceae > Amomum

9. Amomum maximum Roxb.wfo-0000339124

Asiat. Res. 11: 344. 1810.— Cardamomum maximum (Roxb.) Kuntze, Revis. Gen. Pl. 2: 687. 1891. Plate XLIII: D.

Accepted Name : This is currently accepted.

Description : Clump-forming herb. Leafy shoot stout, 1.8–3 m tall. Leaf sheath light yellowish green; ligule bilobed, 1.2–4.5 cm long, sparsely white pubescent; blades ovate or oblong, 30–111 by 10–20 cm, glabrous above, tomentose below, margin undulate, base decurrent, unequal, apex acute; petiole sessile to 10 cm long. Inflorescences grouped around bases of leafy shoots, ca 7 cm long; peduncle 8–9 cm long; flowering heads ellipsoid, ca 10–11 flowers open at once in a circle, 10–13 cm diam.; peduncular bracts deltoid to ovate, 2–2.5 by 3–6 cm, reddish brown, outer surface glabrous, apex mucronate, subleathery; fertile bracts oblong or lanceolate, ca 2 by 5 cm, outer surface glabrous, apex round, mucronate, pale brown; bracteoles tubular, ca 1.5 cm long including ovary, cream-white, apex bidentate, outer surface glabrous or slightly pubescent. Flower white; ovary cylindrical, ca 1 cm long, with 10–11 longitudinal lines, smooth; style glabrous; stigma cup-shaped, ostiole narrowly transverse, margin hairy; epigynous glands blunt, linear, ca 5 mm long, yellow; calyx tubular, to 1.5 cm long, cream-white or pink, apex tridentate; corolla cream-white, glabrous, floral tube 2.5–3.5 cm long including ovary, dorsal corolla lobe hooded, oblong, ca 3.5 by 0.9 cm, apex apiculate, lateral corolla lobes narrower, apex blunt to apiculate, hooded; lateral staminodes subulate, ca 3 mm long, white; labellum ovate, spreading, 3.5–4 by 2.5–3 cm, base attenuate, apex round, margin crenulate, with golden yellow to brownish red patch below anther and radial translucent lines towards margin; stamen: filament 1–2 mm long, glabrous; anther 1–1.4 cm by 5 mm, dehiscing lengthwise, yellowish white, glabrous; anther crest fan-shaped, spreading, apex truncate or slightly trilobed, slightly revolute, membranous, ca 1.2 by 0.5 cm, cream-white. Fruit ovoid, 9–11-winged, 2.5–3 by 1.8–2.4 cm, glabrescent, light green or purplish green turning brown, with stigmatic remains at apex; seeds white turning reddish brown, aril white.

Thailand : NORTHERN: Lampang (Ngao); SOUTH-WESTERN: Kanchanaburi (Thong Pha Phum, Nong Prue, Thung Yai Naresuan); PENINSULAR: Yala (Betong, Wang Sai). Cultivated plants at Hala-Bala.

Distribution : India, Sri Lanka, China, Myanmar, Peninsular Malaysia, Vietnam?, Laos?.

Ecology : Tropical rain forests, on sandy and acidic soil, 400–800 m alt.

Vernacular : Reo yai (เร่วใหญ่).

Notes: In the protologue, Roxburgh stated that Amomum maximum was a native of the Malay Archipelago. This species appears to be widely cultivated in SE Asia, being known as far east as New Guinea. Further study is required to clarify the natural range and to typify the name.