Calamus katikii 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 : 72-74

6. Calamus katikii W.J.Baker & J.Dransf. , sp. nov. Type:— PAPUA NEW GUINEA. Morobe Province: Wau

Subprovince, Kodama Range, Mount Walker, Korpera River, 1829 m, 7°20’S, 146°40’E, 16 November 1981, Katik

LAE 74954 (holotype LAE!, isotypes NSW, USF).

Diagnosis:— Distinguished by the slender habit, ecirrate leaves with very few (ca. 4 pairs) grouped leaflets, the sparsely armed, flagellate leaf sheaths, the short inflorescence with flagelliform tip and large fruit relative to the size of the plant.

Very slender rattan climbing to 5 m. Stem with sheaths 3.5–5 mm diam., without sheaths ca. 3 mm diam.; internodes 9.5–12 cm. Leaf ecirrate, to 24 cm long including petiole; sheath orange-green, with indumentum of sparse, minute, dark hair-like scales, interspersed with translucent, crustaceous scales, sparsely armed with narrow, brown-black, needle-like spines 2–4 mm long; knee ca. 8 mm long, ca. 4 mm wide, with spines and indumentum as sheath, though scales denser; ocrea ca. 1.5 mm high, insignificant, tightly sheathing, armature as sheath; flagellum present, at least 35 cm long, only incomplete material seen; petiole 16–18 mm long, 1.5–2 mm wide and ca. 1.5 mm thick at base, shallowly channelled adaxially, rounded abaxially, indumentum as sheath, armed with few, recurved, hook-like spines; rachis 9–10 cm, armed with few, recurved grapnel spines; leaflets 4 each side of rachis, arranged in two widely spaced groups, narrowly elliptic, longest leaflets in lower group, ca. 13 × 1.2–1.5 cm, apical leaflets 11.5–13 × 1.2–1.4 cm, apical leaflet pair united to one fifth of their length, leaflets almost unarmed except for minute dark bristles on margins at apex, with scattered indumentum as sheath, transverse veinlets moderately conspicuous. Staminate inflorescence not seen. Staminate flowers not seen. Pistillate inflorescence arching, ca. 40 cm long including 11 cm peduncle and 19 cm flagelliform tip, branched to 2 orders; prophyll ca. 7 × 0.3 cm, strictly tubular, armature and indumentum as sheath; peduncular bracts absent, rachis bracts ca. 5 × 0.3 cm, similar to prophyll; primary branches 2, to 3.7 cm long, 10 cm apart, with up to ca. 6 rachillae; rachillae 5–12 mm × ca. 2 mm, sinuous; rachilla bracts 1–2 × 1.5 mm, widely spaced, funnel-shaped, indumentum as sheath; proximal floral bracteole ca 2.5 × 2.5 mm, distal floral bracteole ca. 2 × 2 mm, scar from sterile staminate 0.6–1 mm diam., round to elliptic, raised. Pistillate flowers not seen. Sterile staminate flowers not seen. Fruit globose, ca. 20 × 15 mm including beak 2 × 0.5 mm, with 16 longitudinal rows of cream-orange scales, channelled with minutely fimbriate margins. Seed (sarcotesta removed) ca. 12 × 6 × 9 mm, ellipsoid with broad, shallow pit; endosperm homogeneous; embryo basal.

Etymology:— This species is named for Paul Katik, renowned botanist, formerly of the Papua New Guinea Forest Research Institute, and collector of the type specimen.

Distribution:— Known only from a single collection from the Kodama Range, Morobe Province, Papua New Guinea.

Habitat:— Montane, mossy forest at ca. 1800 m.

Uses:— None recorded.

Vernacular names:— None recorded.

Specimens examined:— PAPUA NEW GUINEA. Morobe Province: Wau Subprovince, Kodama Range, Mount Walker, Korpera River, 1829 m, 7°20’S, 146°40’E, 16 November 1981, Katik LAE 74954 (holotype LAE!, isotypes NSW, USF).

Notes:— This new species most closely resembles C. cuthbertsonii Beccari (1888: 179) in its very slender habit, short inflorescences and narrow leaflets. The two species appear also to overlap in range. Calamus katikii is however readily distinguished by its small number of leaflets (4 pairs, rather than 5–13 pairs), which are arranged in two distant groups as opposed to being regularly to subregularly arranged, and its sparser armature. Its inflorescence is also distinct in having a short flagelliform tip, which is entirely lacking in C. cuthbertsonii . Calamus katikii also produces a disproportionately robust fruit, up to 20 mm long, which is not known in C. cuthbertsonii .

Calamus katikii also resembles closely some unusual specimens of C. johnsii Baker & Dransfield (2014: 193) from Sudest Island (Johns 12839 & Maru [BRIT, K!, L, LAE, UPNG], Brass 27857 [K!, L!, LAE!]) in slender habit, leaf structure and the rather large fruit. However, C. johnsii is known from 13 records, none of which occurs above 350 m, whereas C. katikii is known only from ca. 1800 m. The type locality of C. katikii is ca. 900 km from the locations of these two unusual specimens, and other records of C. johnsii that occur nearest to C. katikii are consistent with the robust typical form of the species. Calamus katikii can be distinguished from the two unusual C. johnsii specimens by being less heavily armed, somewhat smaller in stature with shorter primary branching that does not split the strictly tubular rachis bracts, unlike the rachis bracts of C. johnsii , which are often somewhat split at the apex by the emerging primary bracts.

Vegetatively, C. katikii could also be confused with C. anomalus or C. essigii from the nearby Owen Stanley Range, but these species are immediately distinguished by their characteristic inflorescence morphology.