Clustered slender palm climbing to 10-15 m. Stem, often branching, without sheaths up to 15 mm in diameter, with ca. 20 mm; internodes 10-20 cm long. Leaf sheath moderately to sparsely armed with black tipped, pale coloured bulbous-based, upward pointing or reflexed spines; sheaths near inflorescence occasionally very sparsely armed; black caducous indumentum present on mature sheaths; ocrea 12-30 cm long, gradually tapering at the apex, papyraceous and tattering, pale straw-coloured without, dark shiny brown within, armed with black-tipped spines with pale bulbous bases, particularly at apex. Leaves up to 1.2 m long; petiole to 12 cm long by 0.8 cm wide, abaxially rounded, adaxially flattened, armed along the edges with up to 1 cm long, inequidistant, black spines with pale bulbous bases, spreading or reflexed; rachis to 60 cm long, rounded or somewhat angular in cross section, armed as the petiole, the spines decreasing in size distally; cirrus to 50 cm long armed as the rachis, although spines becoming sparse distally; leaflets composed of 2-4s fold, 10-12 on each side of the rachis, inequidistant and unequal in size, usually sub-equidistant proximally and borne in pairs distally, sigmoid, 1-5-costulate, the largest 20-30 cm long by 2.5-10 cm broad at widest point, ± concolourous, with prominent transverse veinlets and numerous, rather distant, small spines on the margins; acanthophylls to 2.5 cm long. Inflorescences, numbering 4-8, produced simultaneously in distal 30-50 cm of stem; peduncle ca. 10 cm long; prophyll ca. 4 cm; lower bracts up to 2 cm long, gradually decreasing distally, with a short triangular acuminate lobe, closely adpressed to the next bract, finely striate; rachillae to 10 cm long, spreading, densely clothed with striate imbricate bracts 4 mm distant, each with a rather wide mouth and short apiculum to 1 mm; bracteoles minute. Flowers 8 mm long by 2 mm wide; calyx, tan-cream, 4 mm long, tubular in the basal 2 mm, with 3 triangular striate lobes 2 mm long by 2 mm wide; petals cream or white, 9 mm long by 2.5 mm wide, lanceolate with a blunt triangular tip; stamen-filaments to 3 mm long by 1 mm wide, minutely epipetalous and united into a very short (less than 1 mm) basal tube; anthers to 3 mm long 1 mm wide, ovary 1 mm in diameter, stigma to 5 mm long. Fruit rounded, somewhat depressed apically, ca. 1.2 cm in diameter, covered in 12-14 vertical rows of pale brown scales with slightly paler margins and each with a central furrow. Seed sub-globose, 6-8 mm in diameter, covered in polygonal rounded depressions, deeply scalloped on one side.
Tolerant of deep shade, L. opacum is commonly found in high forest in the lower to mid-canopy. This species prefers well-drained soil and is the only species of rattan found on basalt and other volcanic soil types.
Heimisch in, Cameroon, Central African Republic, Congo, Equatorial Guinea, Gabon, Ghana, Liberia, Nigeria, Uganda, Democratic Republic of the Congo
Laccosperma opacum ranges from Liberia and Ivory Coast to Cameroon, Gabon and the Congo Basin to eastern Democratic Republic of Congo. This taxon is the only species of rattan known to occur on the island of Bioko.