Iguanura brevipes Hooker (1892: 416)

Henderson, Andrew, 2025, A revision of Iguanura (Arecaceae, Arecoideae, Areceae), Phytotaxa 690 (2), pp. 135-188 : 151-152

5. Iguanura brevipes Hooker (1892: 416) . Type:— MALAYSIA. Perak, Larut, 3,000 –4,000 ft., July 1881, Dr. King’s collector 2029 (holotype K-000207991!, K-000207992!).

Iguanura polymorpha var. canina Beccari (1889: 190) . Type:— MALAYSIA. District of Perak in the Malay Peninsula, no date, B. Scortechini s.n. (holotype FI-014154!).

Iguanura ferruginea Ridley (1904a: 40) . Lectotype (designated by Saw 2023):— MALAYSIA. Perak, Box Hill, October 1899, W. Fox 10684 (lectotype SING-0151652!, isolectotypes SING-0151651!, SING-0151653!).

Stems 2.5(1.5–3.5) m long, 0.9(0.7–1.2) cm diameter, solitary. Leaf sheaths 11.9(9.5–14.5) cm long, tubular, mostly closed opposite the petiole, cleanly falling, covered with a thin layer of indumentum; ocreas scarcely developed; petioles 11.6(7.7–17.0) cm long; rachises 36.9(29.5–58.0) cm long; leaf blades divided, not rounded at the apex, with a deep split; leaf veins diverging; adaxial veins not prominent, triangular in cross-section; pinnae 5(3–7) per side of rachis; middle pinna 15.2(10.2–21.5) cm long, 5.3(3.7–7.0) cm wide. Inflorescences branched to 1 or 2 orders; prophylls and peduncular bracts inserted some distance apart, more or less persistent; peduncles 14.3(3.0–20.0) cm long, not wooly tomentose; rachises 7.5(3.2–15.5) cm long; rachillae 9(5–12), 10.8(4.8–15.7) cm long, 1.3(0.7–1.7) mm diameter, widely diverging from the rachis, proximal part of rachillae not with distantly spaced triads, glabrous or sparsely to densely tomentose, not filiform with triads sunken in shallow, more or less closely spaced pits; rachilla bracts not elongate; distal triad bracteoles scarcely developed or absent, less often well-developed; distal part of flower pits densely tomentose; staminate flowers 2.0– 2.5 mm long with blunt apices; anther margins not undulate; fruits 15.4(12.8–17.8) mm long, 5.4(5.0–5.6) mm diameter, narrowly ovoid and often curved, not ridged, the surfaces drying pebbled, black; endocarp circular in cross-section; endosperm homogeneous.

Distribution and habitat:— Northwestern Peninsular Malaysia in high forest, primary forest, lower montane forest, or montane forest at 1,038(600–1,294) m elevation ( Fig. 8 ).

Taxonomic notes:— Preliminary species Iguanura divergens was polymorphic for nine variables (stem branching, leaf sheaths, ocreas, orders of inflorescence branching, rachillae tomentum, rachillae thickness, distal triad bracteole, flower pit tomentum, fruit shape). Much of this polymorphism was based on several aberrant specimens which are here considered to be part of I. polymorpha (see notes under that species). With these excluded, eight variables were polymorphic (leaf sheaths, ocreas, orders of inflorescence branching, rachillae tomentum, rachillae thickness, distal triad bracteole, flower pit tomentum, fruit shape). Six of these were treated as traits, and the other two (leaf sheaths, rachillae thickness) were used to split preliminary species I. divergens into two phylogenetic species, I. brevipes and I. tenuis . The name I. brevipes is used here, rather than I. divergens . Saw (2023) included the type of I. brevipes in his I. polymorpha . However, this type, along with many other specimens from the type locality (included by Saw in I. divergens ), clearly belong together here. Iguanura brevipes is characterized by its scarcely developed ocreas and narrowly ovoid fruits. It also has a high elevation habitat. All specimens are from Gunung Bubu or Bukit Larut in Perak.

Iguanura brevipes is part of a group of morphologically similar and taxonomically difficult species. Saw (2022) considered that five of the species he recognized were part of an I. polymorpha species complex: I. bicornis , I. divergens (including I. belumensis , I. brevipes , I perdana , and I. tenuis ), I. mirabilis , I. parvula (including I. speciosa ), and I. polymorpha (including I. corniculata and I. thalangensis ). Saw considered this complex to be highly polymorphic and thus species delimitation difficult. Here, these are recognized as follows: I. bicornis , I. brevipes , I. mirabilis , I. parvula (including I. speciosa ), I. polymorpha (including I. corniculata , I. belumensis , I. divergens ), I. tenuis , and I. thalangensis .

Figures

FIGURE 8. Distribution of Iguanura brevipes, I. bruneiensis, I. chaiana, and I. curvata.