Iguanura thalangensis Lim (1998b: 114)

Henderson, Andrew, 2025, A revision of Iguanura (Arecaceae, Arecoideae, Areceae), Phytotaxa 690 (2), pp. 135-188 : 179-180

29. Iguanura thalangensis Lim (1998b: 114) . Type:— THAILAND. Phuket, Khao Pra Taew, 1997, Lim Chong Keat H 1995 (holotype BFK n.v., isotype KEP n.v.). According to Saw (2023) the specimens were not distributed to these herbaria. Plate 9.

Stems 1.3 m long, 0.7(0.6–0.9) cm diameter, solitary. Leaf sheaths 6.4(5.5–7.5) cm long, swollen, mostly open opposite the petiole, cleanly falling, covered with a thin layer of indumentum; ocreas well-developed, separating early into fibers and disintegrating; petioles 4.5(1.0–7.5) cm long; rachises 43.9(22.5–80.0) cm long; leaf blades divided, not rounded at the apex, with a deep split; leaf veins diverging; adaxial leaf veins not prominent, triangular in cross-section; pinnae 5(4–8) per side of rachis; middle pinna 18.8(12.5–25.0) cm long, 4.2(1.2–7.7) cm wide. Inflorescences spicate or branched to 1 order; prophylls and peduncular bracts inserted some distance apart, more or less persistent; peduncles 16.0(12.0–22.0) cm long, not wooly tomentose; rachises 0.6(0.0–2.5) cm long; rachillae 2(1–4), 22.1(15.5–29.0) cm long, 2.4(1.8–2.9) mm diameter, widely diverging from the rachis, proximal part of rachillae not with distantly spaced triads, glabrous or sparsely tomentose, not filiform with triads sunken in shallow, more or less closely spaced pits; 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 not undulate; fruits 13.6(12.2–13.9) mm long, 7.1(6.2–8.3) mm diameter, ellipsoid, not ridged, the surfaces drying pebbled, purplish; endocarp circular in cross-section; endosperm homogeneous.

Distribution and habitat:— Western Peninsular Thailand in hill Dipterocarp forest or evergreen forest at 584(37– 1,200) m elevation (Fig. 14).

Taxonomic notes:— Iguanura thalangensis is recognized as a phylogenetic species—see notes under I. polymorpha . It is characterized by its swollen leaf sheaths and non-filiform rachillae. Iguanura thalangensis was included by Saw (2023) as a synonym of I. polymorpha .