Iguanura magna (Kiew) Henderson

Henderson, Andrew, 2025, A revision of Iguanura (Arecaceae, Arecoideae, Areceae), Phytotaxa 690 (2), pp. 135-188 : 165-166

16. Iguanura magna (Kiew) Henderson , comb. & stat. nov. Iguanura palmuncula var. magna Kiew (1976: 212) . Type:— MALAYSIA. Sarawak, Serian, Gunung Gaharu, 2,000 ft., 1 August 1962, J. Anderson S.15319 (holotype SARF n.v., isotypes K-000207981!, K-000207980!, SAR!).

Stems 0.7(0.4–1.0) m long, 0.9(0.7–1.4) cm diameter, clustered. Leaf sheaths 11.0(8.0–14.0) cm long, tubular, mostly closed opposite the petiole, cleanly falling, covered with a thin layer of indumentum; ocreas scarcely developed; petioles 23.2(14.5–42.0) cm long; rachises 37.8(29.0–51.5) cm long; leaf blades divided, not rounded at the apex, with a deep split; leaf veins parallel; adaxial leaf veins prominent, rectangular in cross-section; pinnae 5(3–6) per side of rachis; middle pinna 15.6(12.0–19.5) cm long, 3.7(2.5–5.0) cm wide. Inflorescences branched to 1or 2 orders; prophylls and peduncular bracts inserted some distance apart, more or less persistent; peduncles 19.0(9.7–33.5) cm long, densely reddish-brown, wooly tomentose; rachises 7.6(4.0–14.4) cm long; rachillae 13(8–18), 11.4(6.5–15.5) cm long, 0.8(0.6–1.0) mm diameter, widely diverging from the rachis, proximal part of rachillae not with distantly spaced triads, glabrous or sparsely to densely tomentose, filiform with superficial, distantly spaced triads; rachilla bracts not elongate; distal triad bracteoles well-developed; distal part of flower pits glabrous; staminate flowers 2.0– 2.5 mm long with blunt apices; anther margins undulate; fruits 12.3(11.2–14.3) mm long, 6.5(5.8–7.7) mm diameter, oblong, apiculate, ridged, the surfaces drying smooth, white, white to pink, or red; endocarp semicircular in cross-section; endosperm homogeneous.

Distribution and habitat:— Malaysia ( Sarawak) in mixed Dipterocarp forest or peat swamp forest, at 219(4– 610) m elevation (Fig. 11). One specimen ( Yii Puan Ching S. 41111) is recorded from an elevation of 1,450 m, although it is not clear if this refers to the elevation of the collecting locality or, more likely, to the summit of the Klingkang Range.

Taxonomic notes:— Iguanura magna is recognized as a phylogenetic species—see notes under Iguanura palmuncula . It is characterized by its scarcely developed ocreas, filiform rachillae, and oblong, apiculate fruits. Although the ocrea is scored as absent, some specimens have a row of brown, fused hairs along the upper sheath margins.

One specimen (Jamree S.75823) has staminate flowers that are 3.5 mm long, but is otherwise similar to I. magna . It lacks fruits and is here unidentified.