Calamus novae-georgii 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 : 76-78

8. Calamus novae-georgii W.J.Baker & J.Dransf. , sp. nov. Type:— SOLOMON ISLANDS. New Georgia: MundaNoro Road, 8°15’S 157°19’E, 12 September 1991, Qusa 124 (BSIP 22101) (holotype K!).

Diagnosis:— Distinguished by the sheaths with dense chocolate-brown indumentum and abundant straw-coloured spines, the long, slender, flagelliform inflorescence, the fine, zig-zag rachillae and the stalk-like first bracteole in the dyad of the pistillate inflorescence.

Moderately robust, solitary rattan climbing to 8–10 m tall. Stem with sheaths 13–25 mm diam., without sheaths to 12– 16 mm diam.; internodes ca. 18 cm (only one complete sample available). Leaf ecirrate or slightly subcirrate, to 95 cm long including petiole; sheath dull brown, densely covered with chocolate-brown indument, spines dense, varying in size and orientation, 1–30 × 1 mm, slender, needle-like or flattened, with slightly swollen bases, straw-coloured, more or less glabrous, scattered or partially grouped horizontally; knee 30–60 mm long, 5–7 mm wide, similar in colour to rest of sheath, armed as the sheath or very sparsely armed, spines around the leaf sheath mouth generally larger and upward pointing; ocrea to 0.5 cm, on either side of petiole, membranous, dark brown, unarmed or with a few sparse, short spines, disintegrating; flagellum ca. 2 m long; petiole 13–24 cm long, 8 mm wide, 5 mm thick at base, adaxially slightly channelled or flattened, rounded abaxially, glabrous or with scattered, caducous, chocolate-brown scales, armed with a few long spines to 30 mm long on margins near base, scattered or dense short triangular spines distally; rachis to 70 cm long, armed with scattered bulbous-based reflexed spines abaxially, with short scattered or grouped spines adaxially; leaflets 35 on each side of rachis, regularly arranged, linear to narrowly lanceolate, longest leaflet at mid-leaf position 26 1.7 cm, apical leaflets 10 × 0.4 cm, apical leaflet pair free, leaflets bearing abundant bristles 2–3 mm long on margins and 3 veins adaxially and abaxially, glabrous, transverse veinlets conspicuous, close; cirrus absent. Staminate inflorescence flagelliform, to at least 1.9 m long, peduncle not seen, flagelliform tip to at least 90 cm long, branched to 3 orders; prophyll (only base seen), ca. 10 mm wide, armed with long golden spines to 22 mm long along the margins, and abundant mid brown caducous indument; peduncular bracts not seen; rachis bracts to 32 0.7 cm, strictly tubular and not splitting, distally armed with very sparse spines and sparse caducous brown indument; primary branches at least 3, to 25 cm long, ca. 40 cm apart, with up to 80 rachillae, bracts on first order branches inconspicuous; rachillae 5–30 mm × 1 mm, zigzag; rachilla bracts 0.7 mm, distichous, explanate with an attenuate triangular tip, with quite dense brown scaly indument; floral bracteole minute. Staminate flowers 3 1 mm prior to anthesis; calyx 1.5 mm diam., tubular in basal 1.2 mm, with 3 triangular lobes 0.3 0.3 mm, glabrous; corolla 2.5 × 1.5 mm in bud, tubular in basal 0.1 mm, glabrous; stamens 6, filaments 1.5 0.2 mm, anthers 1.5 × 0.5 mm; pistillode 0.7 0.1 mm, trifid. Pistillate inflorescence similar to staminate inflorescence, flagelliform, ca. 2 m long including at least 0.8 m peduncle and 0.9 m flagelliform tip, branched to 2 orders; prophyll 30 × 0.7 cm, strictly tubular, not splitting, indument brown, sparse, caducous, armed along margins with scattered short triangular spines; peduncular bracts 1 (?always), peduncular and rachis bracts 20–25 × 0.2–0.5 cm, strictly tubular, not splitting, with sparse brown indument, sparse short black-tipped reflexed spines to 1 mm; primary branches to at least 3, to 21 cm long, to 28 cm apart, rather distant, tending to be more or less triangular in outline, with up to 25 rachillae; rachillae 5–70 mm × 1 mm, somewhat reflexed and somewhat zigzag; rachilla bracts 1.1 mm, triangular, reflexed, striate with abundant chocolatecoloured scales; proximal floral bracteole pedicelliform, 1.0 0.7 mm, distal floral bracteole very inconspicuous, ca. 0.1 mm, scar from sterile staminate flower 0.5 0.3 mm, oval. Pistillate flowers not seen. Sterile staminate flowers not seen. Fruit at maturity rounded, 7 7 mm including beak 0.5 × 0.5 mm, with 15 longitudinal rows of straw-coloured, slightly channelled scales with dark margins and tips. Seed (sarcotesta removed) 5 × 4.5 × 4 mm, slightly flattened on one side; endosperm homogeneous with a rounded lateral intrusion; embryo sub-basal.

Etymology:— The species epithet reflects the type locality on New Georgia Island.

Distribution:— Known only from New Georgia Island in the Solomon Islands.

Habitat:— Primary, lowland forest on hills, ridges and flat plains.

Uses:— None recorded.

Vernacular names:— Hezi (New Georgia)

Specimens examined:— SOLOMON ISLANDS. New Georgia : 17 May 1929, Waterhouse 22 ( K!) ; Munda-Noro Road , 8°15’S 157°19’E, 12 September 1991, Qusa 123 ( BSIP 22100 ) ( K!), Qusa 124 ( BSIP 22101 ) (holotype K!), 13 September 1991, Qusa 127 ( BSIP 22104 ) ( K!), Qusa 128 ( BSIP 22105 ) ( K!) .

Notes:— Calamus novae-georgii is unusual among Papuasian and West Pacific Calamus species in the stalk-like first bract in the dyad of the pistillate inflorescence. The rachillae appear zigzag and with peg-like protrusions on which are borne the flowers and fruit. Such ‘pedicelliform involucrophores’ are a feature of C. heteracanthus Zippelius ex Blume (1847: 56) and the species previously included in Daemonorops Blume in Schultes & Schultes (1830: 1333). However, this new species with its flagelliform inflorescence is quite unrelated to Daemonorops and furthermore in vegetative details C. novae-georgii is completely different from C. heteracanthus , in having much more slender stems, armed very differently, with narrow ciliate-hairy leaflets. Based on the available morphological evidence, the relatives of this very distinctive species are not at all obvious.