A clump-forming, smallish, water-loving, fast growing, dioecious, forest understorey, climbing palm. Not known in cultivation, rare in the wild. It has spiny, green stems, 3 m. (10 ft.) tall, 1 cm. (0.4 inch) diameter with no obvious leaf scars, and large segmented, pinnate (feather) leaves, 0.9 m. (3 ft.) long, 0.6 m. (2 ft.) wide, light green above and, greyish white beneath. Flagella absent Cirri absent.
Calamus minor naturally occurs in wet and humid tropical rainforest. In this type of natural environment temperature fluctuations are slight, and this palm prefers a constantly hot and humid climate with little temperature difference between day & night, and Summer & Winter. This palm will not tolerate cool for very long.
Stems clustered, 2.5-3 m long and 0.7-1 cm diameter (with leaf sheaths). Leaf sheaths greenish-yellow, sparsely covered with brown, black-tipped, flattened, horizontally or upward spreading spines to 1.4 cm long, those at sheath apex sometimes to 2.5 cm long; knees present; ocreas present, to 0.3 cm long, fibrous, disintegrating; flagella absent; petioles 3-10 cm long, sparsely covered laterally and abaxially with recurved spines to 0.5 cm long; rachis 40-70 cm long, abaxially with few, recurved, solitary spines; pinnae 5-6 per side of rachis, lanceolate, regularly but distantly arranged, 15-30 cm long, 1.7-4 cm wide, gray abaxially, without marginal spines except near apices, the apical pair of pinnae only briefly joined at their bases; cirri absent. Inflorescences 0.2-0.4 m long, briefly or not flagellate; partial inflorescences inserted at the base of the partial inflorescence bract; partial inflorescence bracts open and not sheathing the main axis, not spiny; staminate inflorescences branched to three orders, with 4-6 partial inflorescences; rachillae to 0.5 cm long; rachillae bracts distichously arranged, to 1 mm long, glabrous; floral bracteoles 0.5 mm long, glabrous; staminate flowers to 3.5 mm long, to 10 per rachilla, arranged alternately and distichously along the rachillae; calyx 2 mm long, tubular except for the 3-lobed apex; corolla 3 mm long, with 3 valvate petals free to the base; pistillode absent; pistillate inflorescences branched to two orders, with up to six partial inflorescences; rachillae to 1.5 cm long; rachillae bracts distichously arranged; pistillate flowers not seen; fruits not seen.
Notes: The Lao specimens cited here were included by Evans et al. (2002) in Calamus hypoleucus, a species known only from Myanmar. However, as noted by Evans et al., the Lao specimens have longer leaves and narrower pinnae, these with spiny margins near the apex, and longer inflorescences.
Native to, Laos
Bolikhamsay: Thaphabat Province, close to Ban Hatkhai, 140 m.