Calamus superciliatus W.J.Baker & J.Dransf., 2017

Baker, William J. & Dransfield, John, 2017, More new rattans from New Guinea and the Solomon Islands (Calamus, Arecaceae), Phytotaxa 305 (2), pp. 61-86 : 82-84

11. Calamus superciliatus W.J.Baker & J.Dransf. , sp. nov. Type:— INDONESIA. West Papua Province: Tambrouw

Regency, Fef District, forest above Fef, 730 m, 0°49’35”S, 132°27’41”E, 24 January 2013, Baker et al. 1370 (holotype

K!, isotypes BO!, MAN!, L!).

Diagnosis:— Distinguished by the leaf sheaths densely armed with fine, planar spines that form a tuft of longer spines at the sheath mouth, the relatively few leaflets (9–12 pairs) arranged in few, divaricate groups, and the lax, flagelliform inflorescence with few primary branches (1–3).

Slender, clustering rattan climbing to 8 m. Stem with sheaths 8–13 mm diam., without sheaths to 7–8 mm diam.; internodes 17–22 cm; juvenile stems to ca. 1.5 m with sheaths ca. 4–4.5 cm, bearing reduced leaves as short as ca. 9.5 cm in length. Leaf ecirrate to 74–80 cm long including petiole; sheath dark green, with scattered minute, purple-brown scales, densely and evenly armed with fine, planar, rusty-brown spines, spines to ca. 32 × 0.5–0.9 mm, sometimes with scattered colourless or brown fibrous scales, spines very dense, paler, longer (to 58 mm) and erect around sheath mouth, spines falling in older sheaths; knee 28–33 mm long, colour and armature as sheath; ocrea ca. 2–3 mm high, forming an inconspicuous, dry, papery crest extending into the petiole base, persistent, obscured by dense spines; flagellum present, to ca. 1.5 m long; petiole 11–15 cm long, 4.5–6 mm wide and 2.5–4 mm thick at base, shallowly channelled adaxially, rounded abaxially, glabrous or with sparse indumentum as sheath, armed with short spines similar to sheath and grapnel spines abaxially; rachis 46–52 cm, slightly arching, armed abaxially with grapnel spines; leaflets 9–12 each side of rachis, arranged in 3–5 widely spaced, divaricate groups, linear lanceolate, longest leaflet near base 27–29 × 2.3–2.5 cm, mid-leaf leaflets 24–27 × 2.1–3 cm, apical leaflets 18–19 × 1.7–2.8 cm, apical leaflet pair not or scarcely united at the base, leaflets very sparsely armed with few marginal bristles and very few bristles on adaxial surface of mid-rib, leaflet lacking indumentum, transverse veinlets moderately conspicuous. Staminate inflorescence not seen. Staminate flowers not seen. Pistillate inflorescence flagelliform, to ca. 2.2 m long including ca. 1.4 m peduncle and ca. 35 cm flagelliform tip, branched to 2 orders; prophyll 25–28 × 0.3–0.4 cm, strictly tubular, splitting slightly at apex, indumentum and armature similar to sheath, though spines shorter; peduncular bracts at least 2, peduncular and rachis bracts similar to prophyll; primary branches 1–3, to 55 cm long, ca. 30 cm apart, pendulous, lax, with up to ca. 18 rachillae, bracts 25–30 × ca. 2 mm, elongate, narrowly funnel-shaped; rachillae 20–70 mm × ca. 1.5 mm, recurved; rachilla bracts 1.5–2 × ca. 1.5 mm, distichous or somewhat subdistichous, cup-shaped, with indumentum of scattered brown scales; proximal floral bracteole ca. 1.8 × 1.5 mm, distal floral bracteole ca. 1.5 × 1.5 mm, saucer-shaped, scar from sterile staminate inconspicuous. Pistillate flowers 2.6–3 × ca. 1.5 mm in early bud, immature. Sterile staminate flowers ca. 1.8 × 1 mm in early bud, immature. Fruit globose, ca. 13 × 8 mm including beak 1 × 1 mm, with ca. 18 longitudinal rows of cream-white, shallowly channelled scales, sarcotesta ca. 0.6 mm thick. Seed (sarcotesta removed) 8.5 × 7.8 × 5.7 mm, globose with deep lateral intrusion, shallowly channeled; endosperm homogeneous; embryo basal.

Etymology:— The specific epithet refers to the fine, prolonged, erect spines that emerge around the mouth of the leaf sheath.

Distribution:— Known from two localities near Fef in the Tamrau mountains.

Habitat:— Lower montane forest at 700– 900 m.

Uses:— None recorded.

Vernacular names:— None recorded.

Specimens examined:— INDONESIA. West Papua Province: Tambrouw Regency, Fef District, forest above Fef , 730 m, 0°49’35”S, 132°27’41”E, 24 January 2013, Baker et al. 1370 (holotype K!, isotypes BO!, MAN!, L!), 700 m, 0°49’50”S, 132°27’42”E, 25 January 2013, Baker et al. 1373 ( AAU!, BO!, MAN!, K!, L!) ; Tambrouw Regency, Bamusbama District, forest along road to Fef east of Bamusbama , 900 m, 0°46’14”S, 132°18’49”E, 29 January 2013, Baker et al. 1385 ( BO!, MAN!, K!, L!) .

Notes:— Calamus superciliatus is differentiated from other flagellate species lacking conspicuous ocreas in the dense, fine, planar leaf sheath spines that are particularly numerous and longer at the sheath mouth, forming a tuft. The leaves bear only 9–12 pairs of leaflets, which are clustered in few, divaricate groups, the longer leaflets being located near the base, and are very sparsely armed with bristles. The inflorescence is long, fine and flagellum-like and, in the material seen by us, bears few primary branches. Reduced, very slender juvenile stems were also observed at the type locality, which might be confused with C. depauperatus Ridley (1916: 234) . In adult form, however, C. superciliatus is likely to be confused only with C. retroflexus J.Dransf. & W.J.Baker in Baker & Dransfield (2014: 203) on account of leaflet shape and arrangement, and spine shape, but the latter species differs in being more robust (e.g. stems with sheaths 18–21 mm diameter), in the more numerous leaflets (23–30 pairs), and in the absence of both a petiole and the conspicuous tuft of spines at the leaf sheath mouth.