Calamus womersleyi J.Dransf. & W.J.Baker, 2014

Baker, William J. & Dransfield, John, 2014, New rattans from New Guinea (Calamus, Arecaceae), Phytotaxa 163 (4), pp. 181-215 : 211-214

14. Calamus womersleyi J.Dransf. & W.J.Baker , sp. nov. Type:— PAPUA NEW GUINEA. Morobe Province: McAdam Memorial Park , 5 miles S of Wau, 1200 m, 7°24’S, 146°43’E, 12 March 1964, Moore & Womersley 9285 (holotype LAE!, isotype BH!) .

Diagnosis:— Distinguished by its slender stem, rather sparse pale spines, the short, truncate membranous ocrea, the ecirrate leaves with irregularly arranged in groups, usually regularly arranged within groups, narrow lanceolate leaflets and the thin, dark indumentum scattered on leaf sheath and rachis, and inflorescence bracts.

Slender clustering rattan, total length not recorded. Stem with sheaths 13–15 mm diam., without sheaths to 6.5 mm diam.; internodes to 16–19 cm. Leaf ecirrate, 45–69 cm long; sheath drying pale brown, with thick caducous dark brown scales and thin grey indumentum, sheath spines almost absent to abundant, slender, easily detached, rather uniform, 5–19 × 1–1.5 mm, scattered, pale straw coloured with conspicuously swollen bases, horizontal, very narrow triangular, laminar, spines around the leaf sheath mouth absent; knee conspicuous, to 15 × 4.5 mm, drying same colour as sheath, ± unarmed or with a few short spines to 2 mm along the mid-line; ocrea conspicuous, strictly tubular, to 14 mm, truncate, unarmed, membranous, drying dark brown; flagellum present, 1.3 m long; petiole 2–7 cm long, 0.6 cm wide, adaxially flattened, abaxially rounded, bearing caducous dark brown scales and pale indumentum, unarmed or with a few short spines to 3 mm abaxially; rachis to 35–71cm long, basally armed abaxially with scattered short spines as on the leaf sheath and abundant dark brown caducous indumentum, distally armed with recurved hooks, adaxially densely covered with caducous dark brown indument; leaflets 16–24 on each side of rachis, irregularly arranged in 2–4 groups, regularly arranged within the groups, narrowly lanceolate, abruptly constricted at the base, longest leaflet near the base, basalmost leaflets 20–21 × 1.4–2 cm, mid-leaf leaflets 16.5–29 × 1.6–2.2 cm, apical leaflets 10–11 × 1.5cm, apical leaflets joined for ca. 2 cm, leaflets armed with black bristles to 4 mm long along margins near the tip and adaxially along 2 or 4 lateral veins and sometimes also along midrib, abaxially unarmed, leaflets lacking indumentum, transverse veinlets moderately conspicuous. Staminate inflorescence branched to 3 orders, total length unknown; prophyll 32 cm long, closely tubular with a triangular membranous tip, and armed along margins with very sparse short spines, caducous brown indumentum abundant; peduncular bracts absent; rachis bracts not seen; primary branches, total number not known, to at least 22 cm long, the branching system ± triangular in outline, with numerous rachillae; rachillae to 50 × 2.5 mm; rachilla bracts 3 × 2 mm, distichously arranged, overlapping, striate, with apiculate tips and scattered brown indumentum, unarmed; floral bracteole 2 × 0.5 mm, unarmed. Staminate flowers 3 × 2 mm; calyx 2.5 × 1 mm, with triangular lobes to 0.5 × 0.5 mm; petals 2 × 0.7 mm, narrow pointed; stamens not preserved. Pistillate inflorescence to 1 m long, including peduncle 18–43 cm, branched to 2 orders; prophyll 13–23 × 0.7 cm, tubular and closely sheathing, with a triangular lobe, bearing dense caducous brown indumentum and sparse short black spines, mostly to ca. 1 mm; peduncular bracts absent; rachis bracts similar to prophyll, bearing reflexed hooks; primary branches 3–6, 6– 28 cm long, with up to 19 rachillae; rachillae ± arcuate, the middle ones the longest, to 5 × 0.3 cm; rachilla bracts triangular, 4 × 2 mm, distichous, overlapping, unarmed, bearing scattered brown indumentum and fringed with hairs; proximal floral bracteoles to 3 × 1.5 mm, distal floral bracteoles strongly bilobed, 1 × 0.5 mm, scar from sterile staminate minute, 0.1 mm diam. Sterile staminate flower 4 × 1.5 mm; calyx 3.5 × 1.5; petals 3 × 1 mm, other parts not preserved. Pistillate flowers 4.5 × 2.5 mm; calyx 4 × 2.5 mm with lobes 1.5 × 1.5 mm; petals 4 × 1 mm, with gradually narrowing triangular tips; staminodes triangular 0.5 × 0.5 mm; ovary 2 × 1.5 mm with recurved stigmas to 1.5 × 0.4 mm. Fruit globose, 6 mm diam., with ca. 20 vertical rows of pale brown scales with darker margins. Seed 7 × 6.5 × 5.5 mm, with a deep pit on one side, seed surface smooth, endosperm homogeneous, embryo basal. ( Fig. 14 )

Distribution:— Known only from montane forest near Wau and Bulolo, Morobe Province in Papua New Guinea.

Habitat:— Montane forest at ca. 1100–1500 m above sea level.

Uses:— None recorded.

Vernacular Names:— Ren (Biaru).

Specimens examined:— PAPUA NEW GUINEA. Morobe Province: Bulolo, Manki divide range, 1200 m, 7°10’S, 146°40’E, 1 January 1960, Womersley & Thorne NGF 12753 ( LAE!) , Womersley & Thorne NGF 12758 ( LAE!) ; McAdam Memorial Park , 5 miles S of Wau, 1200 m, 7°24’S, 146°43’E, 12 March 1964, Moore & Womersley 9285 (holotype LAE!, isotype BH!) ; Wau Subdistrict, Bulolo, Nauwata Banda , Compound 10, 1463 m, 7°13’S, 146°40’E, 12 June 1969, Zieck NGF 36222 (L!, LAE!) ; Wau Subdistrict, Potmor, Bairu , 1524 m, 7°43’S, 146°46’E, 28 June 1969, Zieck NGF 36224 ( LAE!) ; Wau Subdistrict, Wau , along forestry road no 6, 1370 m, 7°20’S, 146°43’E, 4 July 1969, Zieck NGF 36227 ( LAE!) ; Wau Subdistrict, foothills of Mt. Missim , 1100 m, 7°15’S, 146°42’E, 5 January 1984, Henty & Kini LAE 72548 (L!, LAE)

Notes:— This rattan ( Fig. 14 ), which has been collected several times, but only from montane areas near Wau and Bulolo, is distinguished by its relatively slender stem armed with rather sparse, pale spines, by the short, tightly sheathing, truncate, membranous ocrea, and by the ecirrate leaves with narrow lanceolate leaflets that are arranged in irregular groups, but usually regularly arranged within the groups. Dark caducous indumentum is present in patches on leaf sheath, rachis and inflorescence bracts in the material available to us, lending the specimens a dirty appearance.

Calamus womersleyi appears to be most closely related to C. nanduensis and C. pseudozebrinus (see notes under C. nanduensis ).

This species is named for John Womersley , former Assistant Director of the Division of Botany, Department of Forests, Papua New Guinea, who made several specimens of this species and collected the type specimen with American palm authority, Harold E. Moore, Jr .

Figures

FIGURE 14. Calamus womersleyi. A. Leaf sheath with ocrea and flagellum. B. Leaf diagram. C. Mid-leaf portion. D. Leaf apex. E. Details of leaf rachis with indumentum. F. Portion of pistillate inflorescence. G. Portion of staminate inflorescence. H. Portion of pistillate rachilla. I. Fruit. J, K. Seed in two views. L. Seed in longitudinal section. Scale bar: A = 2.5 cm; B = 24 cm; C, D = 6 cm; E = 1.5 cm; F, G = 8 cm; H, J–L = 7 mm; I = 7 mm. A, C–E, G from Moore & Womersley 9285; B, F, H from Womersley & Thorne NGF 12753; I–L from Womersley & Thorne NGF 12758. Drawn by Lucy T. Smith.