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

Baker, William J. & Dransfield, John, 2014, New rattans from New Guinea (Calamus, Arecaceae), Phytotaxa 163 (4), pp. 181-215 : 193-194

6. Calamus johnsii W.J.Baker & J.Dransf. , sp. nov. Type:— Type: PAPUA NEW GUINEA. Milne Bay Province: Normanby Island , East Sewa Bay , 10°0'10"S, 150°59'25"E, 07 April 2008, Johns 11279 (holotype K!, isotypes BRIT!, L, LAE, SING, UPNG) .

Diagnosis:— Distinguished by its slender stem, the sheaths with fine, scattered black spines with somewhat swollen bases, the ecirrate leaves with petiole very short or absent and few, irregularly arranged, broadly elliptic leaflets with very conspicuous cross veins, by the inflorescences with few, small first order branches and relatively robust primary bracts and by the relatively large fruit.

Slender, clustering rattan climbing to 20 m. Stem with sheaths 4.5–20 mm diam., without sheaths 3.5–7 mm diam.; internodes to 23cm. Leaf ecirrate, to ca. 75 cm long; sheath drying pale green, with thin sparse pale grey indumentum, sheath spines sparse to abundant (rarely absent), slender, persistent, rather uniform, 2–25 × 1–2 mm, scattered or sometimes in horizontal groups of 2–3, shiny black with conspicuously swollen pale green bases, horizontal or slightly reflexed, very narrow triangular, laminar, spines sometimes crowded around the leaf sheath mouth, very slender, some bristle-like; knee conspicuous, to 36 × 13 mm, drying same colour as sheath, ± unarmed or sparsely armed as the rest of the sheath; ocrea scarcely developed; flagellum present, up to at least 1.1m long; petiole very short or absent (rarely up to 4.2 cm long), 2–3.5 mm wide and 2.5–5 mm thick at base, flat adaxially, rounded abaxially; rachis to 50 cm long, variously armed with spines similar to leaf sheath, abaxially armed with recurved hooks; leaflets 5–7 on each side of rachis, irregularly arranged, but scarcely in well defined groups, or rarely arranged in two widely spaced groups (in Sudest Island form), the basalmost pair swept back across the stem, broadly elliptic (or more narrowly so in Sudest Island form), longest leaflet in mid-leaf, basalmost leaflets 10–34 × 0.7–7 cm, mid-leaf leaflets 15–41 × 1.5–8 cm, apical leaflets 11–38 × 1–6.5cm, apical leaflets joined for one fifth to half their length, leaflets unarmed apart from very short sparse black bristles to 2 mm long along margins near the leaflet tips, leaflets lacking indumentum, longitudinal veins 5–7, very conspicuous, transverse veinlets close, sinuous, very conspicuous. Staminate inflorescence branched to 3 orders, up to ca. 1.6 m, including peduncle to ca. 16 cm, with a terminal flagellum to 45 cm; prophyll 14–16 × 0.4–0.6 cm; peduncular bracts absent; rachis bracts to 39 × 0.8 cm with entire triangular tip and bearing scattered reflexed spines to 3 mm with swollen bases; primary branches up to 5, rather distant, to 21 cm long, the branching system ± triangular in outline, with numerous rachillae; rachillae straight to somewhat recurving, longest towards base, to 20 × 1 mm, distalmost to 3 × 1 mm; rachilla bracts 0.5 × 0.6 mm, distichously arranged, striate, with apiculate tips and scattered brown indumentum, unarmed; floral bracteole cuplike, 0.6 × 1 mm, unarmed. Staminate flowers 3 × 1 mm; calyx 2.5 × 1mm, with triangular lobes to 0.5 × 0.5 mm; petals 2 × 0.7 mm, narrow pointed; stamens to 1.5 mm, anthers ca. 0.8 × 0.2 mm. Pistillate inflorescence to 1.7 m long, including peduncle to 88 cm, similar to staminate inflorescence, branched to 2 orders; prophyll to 44 × 0.7 cm, tubular and closely sheathing, similar to staminate inflorescence,with a triangular lobe, sometimes bearing sparse pale brown indumentum and rather densely armed with short black spines, mostly to ca. 1 mm, but occasionally to 8 mm, with conspicuous swollen bases; peduncular bracts absent; rachis bracts similar to staminate inflorescence; primary branches 2–3, 10– 18 cm long, with up to 22 rachillae; rachillae arcuate, the basal the longest, to 5 × 0.2 cm, decreasing towards the tip of the first order branch; rachilla bracts triangular, 2 × 2 mm, distichous, unarmed, bearing scattered brown indument; proximal floral bracteoles explanate, ca. 1.5 mm diam., distal floral bracteoles cup-shaped, 0.5 × 1 mm, scar from sterile staminate ca. 0.3 × 0.1 mm diam. Sterile staminate flower not seen. Pistillate flowers not seen. Fruit broadly ellipsoid, 12– 20 × 10–14 mm, with a beak to 1 × 1.5 mm and covered with ca. 17 vertical rows of matt pale brown scales with darker margins. Seed 10–12 × 7.5–9.5 × 6–7 mm, with a longitudinal groove on one side, seed surface mostly smooth, endosperm homogeneous, embryo basal. ( Fig. 6 )

Distribution:— Known from scattered coastal locations in Morobe Province from Lae southwards and in Milne Bay province from Sudest and Normanby Islands, and adjacent areas of mainland.

Habitat:— Lowland primary and secondary forest from sea level to 350 m.

Uses:— None recorded.

Vernacular names:— Jeje (Dzjedrje).

Specimens examined:— PAPUA NEW GUINEA. Milne Bay Province: Alotau Subdistrict, near Yane Yanene Village , 30 m, 10°17’S, 150°19’E, 14 August 1974, Zieck NGF 36567 (BH, BRI!, CANB, L!, LAE, L!) ; Alotau Subdistrict , 2 km NE of Kaporika village, 200 m, 10°20’S, 150°25’E, 11 May 1978, Essig & Young LAE 74089 (BH!, LAE!) ; Tagula Subdistrict, Lysalys Village , 6 m, 11°30’S, 153°30’E, 08 April 1978, Zieck NGF 36590 (BH, BRI!, L!, LAE) ; Normanby Island, Waikaiuna , 20 m, 10°4’S, 150°58’E, 13 April 1956, Brass 25397 (K!, L!, LAE!) ; Normanby Island, Waikaiuna, Inland half mile from coast, 10°4’S, 150°58’E, 18 April 1956, Womersley & Brass NGF 8604 ( LAE!, BRI!) ; Normanby Island, Sewa Bay , 3 m, 10°0’S, 151°0’E, 21 October 1971, Essig LAE 55061 (BH, CANB, K!, L!, LAE!) ; Normanby Island, E Sewa Bay , 10°0'10"S, 150°59'25"E, 07 April 2008, Johns 11279 (holotype K!, isotypes BRIT!, L, LAE, SING, UPNG) . Sudest Island, Mt. Riu , west slopes, 350 m, 11°31’S, 153°25’E, 25 August 1956, Brass 27857 (K!, L!, LAE!) ; Sudest Island, Yawata River, Rambuso , 5 m, 11°29’S, 153°33’E, 31 January 2009, Johns & Maru 12839 ( BRIT, K!, L, LAE, UPNG) . Morobe Province: Buso River, Lae Subdistrict, 2 m, 7°25’S, 147°10’E, 28 April 1972, Streimann NGF 24479 (BH, LAE!) ; SE of Lae, opposite Lasanga Island , 0 m, 7°25’S, 147°10’E, 24 November 1973, Jacobs 9698 (L!, LAE) ; Morobe, 7°45’S, 147°37’E, 21 January1948, Womersley NGF 3153 ( BRI!, K!, CANB!) ; Lae, Speedway , 6°42'52"S, 147°01'40"E, 24 April 2008, Simaga 9743 ( BRIT, K!, L, LAE, UPNG) .

Notes:— This relatively widespread rattan ( Fig. 6 ) is distinguished by its slender stem, sheaths with fine, scattered black spines with somewhat swollen bases, by its ecirrate leaves with the petiole very short or absent and few, irregularly arranged, broadly elliptic leaflets with very conspicuous cross veins, and by the inflorescences with few, small first order branches and relatively robust primary bracts. The fruits are also distinctive in being among the largest in New Guinea Calamus species and being covered in scales that are usually pale with darker margins. Although the species is morphologically coherent, we note some regional differentiation. The specimens from Morobe are more robust, especially in leaf and inflorescence size, whereas the Sudest Island form is the most slender and bears narrower leaflets in two widely spaced groups. Nevertheless, intermediates exist among the specimens seen by us and taxonomic recognition of these variants cannot be supported.

Calamus johnsii displays superficial vegetative similarities to C. anomalus , C. lucysmithiae , C. nannostachys and C. oresbius . Calamus anomalus and C. nannostachys differ in their unique inflorescence morphology in which the primary bracts are split at or to the base by the emerging primary branches. Calamus lucysmithiae is distinct in several ways, including its well developed, divergent ocrea and its pistillate flowers and fruit being sometimes borne on pedicelliform stalks. Calamus oresbius is a palm of much higher elevations (700–2200 m) and is easily distinguished by its very fine flagelliform inflorescence.

This species is named for our friend and colleague Prof. Robert (Bob) Johns, collector of the type specimen, in recognition of his many contributions to botanical knowledge of New Guinea during his long career in Papua New Guinea and at the Royal Botanic Gardens, Kew .

Figures

FIGURE 6. Calamus johnsii. A. Leaf sheath with basal leaflets and staminate inflorescence. B. Leaf diagram. C. Leaf apex. D. Staminate rachilla. E. Portion of infructescence. F. Fruit. G, H. Seed in two views. I. Seed in longitudinal section. Scale bar: A = 3 cm; B = 25 cm; C = 6 cm; D = 3.3 cm; E = 4 cm; F = 1 cm; G–I = 7 mm. A–D from Essig LAE 55061; E–I from Brass 25397. Drawn by Lucy T. Smith.