Calamus macrochlamys Becc., Ann. Roy. Bot. Gard. (Calcutta) 11(1): 259 (1908)

Primary tabs

no image available


Apparently widespread in lowland New Guinea. (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A


  • This widespread rattan is easily distinguished by its ecirrate leaves, strongly grouped, generally broad lanceolate leaflets, long flagella and distinctive rather leathery persistent swollen ocrea that does not usually tatter. One collection, Dransfield et al. JD7668, from a sago swamp near Timika in Papua is included here but is distinct in its slender pistillate rachillae a mere 1.5 mm diam., and the fruit with yellow scales lacking dark margins. The plant is altogether more slender than typical C. macrochlamys. (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A

Biology And Ecology

  • In lowland and upland forest, including swamp forest, at altitudes up to 1200 m above sea level. (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A


  • Least concern. (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A

Common Name

  • baea (Karimui), arompotto (Kati), kotowo (Goilala-Tapini) (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A


  • Local uses not recorded. (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A


  • Slender to medium-sized, clustering rattan climbing to 50 m. Stem with sheaths (9)14-26 mm diam., without sheaths to (5)8-16 mm diam., exudate not recorded; internodes (6)14 - 38 cm. Leaf ecirrate, to 95 cm long including petiole; sheath bright to dull green, drying pale to dark reddish brown, with sparse to abundant brown indument, rarely unarmed, sheath spines usually abundant, usually rather uniform, 5 - 10 x 2 - 3.5 mm, with conspicuously swollen bases, solitary or very rarely in horizontal groups, pale brown with black tips, horizontal, very rarely erect, very rarely much longer and more slender, acicular and fragile; knee 25 - 90 x 5 - 90 mm, drying pale to mid-brown, unarmed or very rarely sparsely armed as the rest of the sheath; ocrea conspicuous, to 15 - 48 x 2.5 - 4.5 cm, erect, swollen, congenitally split on the far side of the sheath to the petiole, papery or more usually coriaceous, persistent, pale straw-coloured to mid-brown, unarmed or armed with scattered spines as the sheath, or more rarely armed with combs of bristles to 25 x 1 mm or golden spines 24 x 3 mm; flagellum present, to 3.7 m long; petiole 8- 35 cm long, 3 - 8 mm wide and 2 - 5 mm thick at the base, flattened or slightly convex adaxially, abaxially rounded, with sparse indument, and with scattered rigid unarmed, rarely the whole petiole unarmed; rachis to 70 cm long, distally sparsely armed with recurved hooks; leaflets (2)5 - 15 on each side of rachis, arranged in distant groups of 2 - 4, rarely a few solitary leaflets, linear-lanceolate to (more usually) broad lanceolate, longest leaflet often near the base, 35 - 38 x 2.5 - 4.5 cm, mid-leaf leaflets 20 - 37 x 2 - 4 cm, apical leaflets usually in a group of 2 - 6 on each side, displayed in a fan, 9 - 25(38) x 0.7 - 4(6) cm, apical pair of leaflets united for 1/3 to 3/4 their length, surfaces glabrous, lacking bristles except for very short sparse bristles to 1 mm long along the margins, transverse veinlets conspicuous, numerous, sinuous. Staminate inflorescence branched to 3 orders, to 3 m long including the peduncle 23 - 30 cm long and the flagelliform tip 6 - 72 cm long; prophyll to 24 x 1.6 cm, closely sheathing, splitting neatly at its tip, with two triangular lobes to 1.8 x 0.6 cm, covered in very sparse grey indumentum, armed with scattered short triangular spines 2 - 3 mm long, with swollen bases or unarmed; peduncular bracts absent, rachis bracts similar to prophyll but shorter, similarly indumentose, very sparsely spiny or unarmed; primary branches 7 - 9, to at least 6 - 28 cm long, c. 6 - 23 cm apart, with numerous rachillae; rachillae 8 - 45 x 1 - 1.5 mm; rachilla bracts 1.5 - 2 x 1 - 1.5 mm, distichously arranged, explanate, bearing indumentum, particularly along margins, unarmed; floral bracteole 1 x 1 - 1.5 mm, cup-shaped, with sparse indumentum. Staminate flowers (immature) 1.8 x 1.7 mm; calyx 1.7 mm diam., tubular in basal 1 mm, with 3 lobes 0.3 x 1.1 mm, becoming glabrous; corolla 1.5 x 1 mm in bud, tubular in basal 0.1 mm; stamens 6, filaments 0.9 x 0.1 mm, anthers 0.7 x 0.15 mm; pistillode columnar, 0.91 x 0.1 mm. Pistillate inflorescence similar to staminate inflorescence, 0.6 - 1.6 m long including 25 - 35 x 1 cm peduncle and c. 19 cm flagelliform tip, branched to 2 orders; prophyll to 25 - 35 x 1.5 cm, tubular and closely sheathing, splitting apically to give a triangular lobe to 5 x 2 cm, bearing sparse dull brown indumentum and sparse reflexed spines to 2 x 1 mm with swollen bases; peduncular bract absent (always?), rachis bracts to 8 - 18 x 0.5 - 1.4 cm, closely tubular, splitting apically, armed and indumentose as the prophyll; primary branches to 10, to 30 cm long, to 10- 18 cm apart, with up to 18 rachillae; rachillae 30 - 200 x (1.5)2 - 3 mm; rachilla bracts 3 x 2.5 mm, distichously arranged, striate, with a low triangular tip, unarmed, somewhat explanate on drying, with sparse brown indumentum; proximal floral bracteoles 1 mm high, c. 4 mm diam., striate, distal floral bracteoles 2 x 2 mm, scar from sterile staminate c. 0.5 mm diam. Pistillate flowers + at anthesis 4 x 2.5 mm, borne in pairs, together with a single sterile staminate flower to give a triad; calyx tubular in basal 2.5 mm, with lobes 1.5 x 2 mm, striate, glabrous; petals 3 x 1 mm, joined in basal 1.5 mm, striate; perianths splitting and becoming explanate at fruit maturity, star-like; staminodal ring with 6 triangular teeth to 0.75 x 0.5 mm; ovary 1.5 x 1.5 mm, stigmas reflexed. Sterile staminate flower + at anthesis 2 x 1.5 mm; sepals 2 x 1 mm, joined in basal 1 mm; petals 1.5 x 1 mm, striate; sterile stamens c. 1 mm long. Fruit spherical, 10 - 11.5 x 10- 11.5 mm, including beak to 1.5 x 1.5 mm, with 14- 17 vertical rows of pale yellowish brown, channelled scales with dark margins. Seed to 6- 8 x 5 - 7 x 4- 5 mm (sarcotesta removed), irregularly ridged and with a deep pit on the chalazal side; endosperm homogeneous; embryo basal. (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A

Materials Examined

  • INDONESIA, PAPUA. Sorong: Klasaman, km 24, Intimpura Logging Concession, Feb. 1998, Maturbongs 283 (BO, K, MAN); Klasaman, Nov. 1994, Maturbongs 34 (BO, K, MAN). Manokwari: Warmare, Bt Tatbe, Aug. 1995, Dransfield et al. JD7599 (BO, K, MAN); Arfak Mts, Upper Mupi, near Mubri Old Village, April 1995, Maturbongs 43, (K, MAN); Mubri Village, April 1995, Maturbongs 48 (K, MAN); between Wariari and Waoi Rivers, April 1994, Mogea 6306 (BO, K, L, MAN, NY). Mimika: Timika, Mile 21, Freeport Concession, Feb. 1998, Dransfield et al. JD7668 (BO, BH, K, L, MAN); Timika, road from mile 38 to Kali Kopi, Feb. 1998, Baker et al. 817 (AAU, BO, BH, K, L, MAN, NY), Baker et al. 818 (AAU, BO, BH, K, L, MAN); Timika, July 1995, Maturbongs 114 (BO, K, MAN), Maturbongs 219 (BO, K, MAN); Mindiptanah, Dijkstra BW6634 (BO, K, MAN). PAPUA NEW GUINEA. Central: Mafulu, Brass 5423 (Type of C. macrospadix Burret, holotype Bt, isotypes BRI (photo seen)); Tapini, NW of Tapini, Lolaipa R., Dec. 1968, Zieck et al. NGF36186 (L); Karema to Marua, May 1989, Poudyal et al. 81 (K). Eastern Highlands: Kundiawa, Karimui, Dec. 1972, Zieck et al. NGF36513 (BH, K, L, LAE). Gulf: Malalua Subdistr., Merigem near Kakoro/Bulldog, Nov. 1972, Zieck et al. NGF 36543 (BH, CANB, K, L, LAE). Morobe: Sattelberg, Bamler 39 (holotype Bt, isotype fragment FI); Oct. 1935, Clemens 409 (L), Oct. 1935, Clemens 538 (L), March 1936, Clemens 1961 (L), July 1936, Clemens 192 (L); Lae - Mumeng Road, Jan. 1996, Baker et al. 595 (LAE, K); Pindiu, Foria R., Feb. 1996, Baker et al. 677 (LAE, K). Southern Highlands, Moro, Ulisili, Feb. 1996, Baker et al. 654 (LAE, K); Erave Distr., 89 km NW of Kikori, Nov. 2000, Baker et al. 1124 (AAU, K, L, NY). (Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit)A


    A. Dransfield, J. & Baker, W.J. 2003: An Account of the Papuasian Species of Calamus (Arecaceae) with Paired Fruit