Calamus oresbius 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 : 200-203

publication ID 10.11646/phytotaxa.163.4.1

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scientific name

Calamus oresbius W.J.Baker & J.Dransf.


9. Calamus oresbius W.J.Baker & J.Dransf. , sp. nov. Type:— PAPUA NEW GUINEA. Southern Highlands Province: Erave District, side of road to Gobe oil rigs, 91 km NW of Kikori, 1000 m, 6°46'46"S, 143°43'59"E, 27 November 2000, Baker et al. 1122 (holotype K!, isotypes AAU!, BRI!, L!, LAE!, NY!) GoogleMaps .

Diagnosis:— Distinguished by its slender, flagellate stems, the short leaves with 3–6 pairs of broad, elliptic or oblanceolate, leathery leaflets, which are usually arranged in two widely spaced groups, and by the narrow, flagelliform inflorescence with fine rachillae.

Slender, clustering rattan climbing to 25 m, though more frequently to ca. 10 m. Stem with sheaths 4–18 mm diam., without sheaths to 3–8 mm diam.; internodes 8–22 cm. Leaf ecirrate, 16–54 cm long including petiole; sheath dull green to yellow-green, with sparse to moderately abundant, thin, grey-brown indumentum comprising brown linear scales and, in some specimens, translucent, amorphous scales, sparsely to densely armed with fine, needle-like, grey to brown spines 0.5–15 mm long (spines minute and erect in Southern Highlands and Western Province forms), sometimes with concentration of longer spines near sheath mouth to 48 mm; knee ca. 7–20 mm long, ca. 4–9 mm wide, unarmed or armed as sheath; ocrea 2–5 mm high, forming a persistent, closely sheathing, dry crest, brown, unarmed or armed as sheath; flagellum 0.3–2 m long (vestigial flagellum ca. 10 cm in very slender forms), armed with recurved grapnel spines; petiole 0.5–12 cm long, 1.5–3.5 × 1.5–3.5 mm at base, flat or shallowly channelled adaxially, rounded abaxially, indumentum and armature as sheath; rachis 5–22 cm, straight, indumentum and armature as sheath; 3–5 (rarely 6) leaflets each side of rachis, typically clustered at leaf apex with 1–2 pairs at base, sometimes with additional leaflets at mid-leaf postion or more rarely clustered in a single group at the leaf apex, elliptic to oblanceolate, sometimes cucullate, leathery, basal leaflets 9–32 × 1–4.5 cm, spreading or somewhat recurved across stem, longest leaflets at leaf apex 11–36 × 2.5–4.5 cm, apical leaflet pair united from one fifth to half their length, leaflet with scattered bristles on margin, especially near tip, otherwise glabrous except for indumentum as rachis at base, transverse veinlets conspicuous and closely spaced. Staminate inflorescence flagelliform, pendulous or trailing, 1–2 m long including ca. 20–100 cm peduncle and ca. 5–20 cm flagelliform tip (much smaller in Hartley 13102, an atypical diminutive form), inflorescence to 40 cm with 7.5 cm peduncle), branched to 2 or sometimes 3 orders, third order of branching occurring only in the lowermost branches of the basal primary branching system; prophyll 19–26 × 0.2–0.4 cm, strictly tubular and tightly sheathing, indumentum as sheath, armed as flagellum; peduncular bracts 0–3, peduncular and rachis bracts similar to prophyll; primary branches 2–8, to 54 cm long, 9–38 cm apart, pendulous, with up to ca. 40 rachillae; rachillae 5.5–45 mm × 1 mm, slender, straight to sinuous; rachilla bracts 1.5 × 1.8–2 mm, distichous, funnel-shaped, glabrous; floral bracteole 0.5 × 0.5 mm, cup-shaped, glabrous. Staminate flowers 2.5–4 × 1.2–1.5 mm in bud prior to anthesis; calyx 1.2–1.5 mm diam., tubular in basal 0.7–1.3 mm, with 3 lobes 0.7–1 × ca. 1 mm, glabrous or with scattered, brown, linear scales; corolla 2.2–3.5 × 1.2–1.3 mm in bud, tubular in basal 0.6–0.7 mm, indumentum as calyx; stamens 6, filaments 1–1.3 × 0.2–0.3 mm, anthers 1.2–1.5 × 0.3–0.4 mm; pistillode 0.3 × 0.3 mm, trifid. Pistillate inflorescence similar to staminate inflorescence, but branched to 2 orders; primary branches 1–3, to 6–40 cm long, 14–21 cm apart, pendulous, with up to 12 rachillae; rachillae 10–48 mm × 1–1.5 mm, straight to sinuous; rachilla bracts 0.8–1 × 2–2.5 mm, subdistichous, funnel-shaped, glabrous or with scattered, brown scales; proximal floral bracteole 1.4–1.5 × ca. 2.2 mm, distal floral bracteole ca. 1 × 1.3–1.7 mm, scar from sterile staminate round, minute, with scattered, brown scales. Pistillate flowers ca. 4 × 2.5 mm at anthesis; calyx ca. 2.5 mm diam., tubular in basal ca. 1.8 mm, with 3 lobes to ca. 1.3 × 1.6 mm, with scattered, brown, linear scales; corolla ca. 3.5 × 2 mm, tubular in basal ca. 2.5 mm, with 3 lobes to 2 × 1.6 mm, indumentum as calyx; staminodes 6, ca. 0.5 mm long, staminodal ring ca. 1.7 mm high; ovary ca. 1.5 × 1.5 mm, globose, style ca. 1 mm long, stigmas 1.5 mm long, strongly recurved. Sterile staminate flowers 2.3 × 1.5 mm in bud, similar to staminate flower, but with empty anthers. Fruit globose, ca. 10–18 × 8–14 mm including beak ca. 2 × 1 mm, with 17–21 longitudinal rows of yellow to orange scales with brown margins. Seed (sarcotesta removed) 6–12 × 6–11 × 4.5–8 mm, globose, seed surface smooth, with a deep, lateral depression; endosperm homogeneous; embryo sub-basal. ( Fig. 9 View FIGURE 9 )

Distribution:— Widespread in the central highlands of Papua New Guinea, though not yet recorded from the easternmost mountains of Oro or Central Province.

Habitat:— Montane rain forest from 700 to 2200 m, including secondary forest. Also cultivated in some areas.

Vernacular names:— Ep (Mendi), Karrikaribu (Koijari), Kral (Bolin), Kurnin (Biaru), Waiang (Bolin, Ganja, Narak, Nondugl, Noltubi), Waiangl (Kuman), Waiink (Bolin), Wajam (Yoowi; Wajamumum for fruits), Wi-kiral (Sinasina).

Uses:— Weaving baskets, armbands, waistbands and finer rattan work. Used as a long-lasting binding in fence- and house-building.

Specimens examined:— PAPUA NEW GUINEA. Simbu Province: Gandigl , Simbu Valley , 2200 m, 5°53’S, 145°4’E, 16 May 1975, Sterly 75-122 (L!) GoogleMaps ; Kundiawa, Bolin Village ( Simasina ), 1675 m, 6°1’S, 144°58’E, 04 December 1972, Zieck NGF 36520 View Materials (BH, K!, LAE!) GoogleMaps ; Near Kerowagi, Kundiawa Sub-district , 1525 m, 5°50’S, 144°50’E, 4 December 1972, Zieck NGF 36522 View Materials ( LAE, L!, BH) GoogleMaps . Eastern Highlands Province: About five miles NE of Okapa, 1524 m, 6°28’S, 145°40’E, 24 September 1964, Hartley 13102 (A, L!, CANB!) GoogleMaps ; Keglsugl, Kundiawa Sub-district , 2135 m, 5°50’S, 145°6’E, 3 December 1972, Zieck NGF 36521 View Materials (BH, LAE!) GoogleMaps ; Sinasina, Kundiawa subdist., 1840 m, 6°7’S, 145°0’E, 06 June 1972, Hide. 108 ( LAE!) GoogleMaps . Morobe Province: 10 km NE of Wau , 1550 m, 7°18’S, 146°47’E, 2 November 1977, Pratt 77-1003 ( LAE!) GoogleMaps ; Kaigan, West of Biaru Valley, Wau subdist., 2195 m, 7°39’S, 146°45’E, 23 June 1969, Zieck NGF 36223 View Materials (L!, LAE) GoogleMaps ; Mt. Missim, Wau area , 1800 m, 7°13’S, 146°49’E, 25 February 1986, van Valkenburg 459 (L!) GoogleMaps ; Road halfway to Yamap, Wau Sub-district, 1500 m, 7°8’S, 146°47’E, August 1969, Kairo NGF 44077 View Materials (BH, BRI, CANB, L, LAE!) GoogleMaps ; Wau, Mt. Missim, Kuper Range , 1250 m, 7°13'0"S, 146°49'0"E, 12 August 1985, Wada et al. 60 ( BRI, KYO, LAE!, U) GoogleMaps ; Wau-Salamau Track 13 km NE of Wau, 1700 m, 7°19’S, 146°48’E, 31 October 1982, Streimann 8670 ( LAE!) GoogleMaps . Southern Highlands Province: Between the Kagua and Wiru roads, ca. 2 miles S of Ialibu patrol post, 2042 m, 6°17’S, 143°59’E, 15 July 1961, Pullen 2745 ( CANB!) GoogleMaps ; Ca. 6 miles W of Kagua patrol post near Wasuma , 1524 m, 6°26’S, 143°48’E, 26 July 1961, Pullen 2804 ( CANB!, LAE) GoogleMaps ; Mt Bosavi, Wasaso, near Bona village , WWF Integrated Conservation and Development Project Area , 700 m, 6°26’S, 142°47’E, 2 February 1996, Baker et al. 609 (K!, LAE!) GoogleMaps ; Mt Bosavi, near Bona Village, WWF Integrated Conservation and Development Project Area , 750 m, 6°26’S, 142°47’E, 3 February 1996, Baker et al. 624 (K!, L, LAE!) GoogleMaps , Baker 627 (K!, L, LAE!) ; Mt Bosavi , northern side, 1250 m, 6°26’S, 142°50’E, 25 September 1973, Jacobs 8782 (L!) GoogleMaps ; Mt Bosavi , northern side, near the mission station, 700 m, 6°26’S, 142°50’E, 04 October 1973, Jacobs 8982 (L!) GoogleMaps ; Erave District, side of road to Gobe oil rigs, 91 km NW of Kikori, 1000 m, 6°46'46"S, 143°43'59"E, 27 November 2000, Baker et al. 1120 ( AAU!, BRI!, LAE!, K!, NY!), Baker et al. 1122 (holotype K!, isotypes AAU!, BRI!, L!, LAE!, NY!) GoogleMaps ; Erave , 1067 m, 6°35’S, 143°55’E, 27 July 1971, Zieck NGF 36259 View Materials (BH, CANB!, BRI!, L, LAE) GoogleMaps . Near Ebenda, Anga Village , 1920 m, 6°13’S, 143°42’E, 25 July 1961, Schodde 1600 (A, CANB! L, LAE) GoogleMaps . Western Highlands Province: 2 miles E of Tabibuga Airstrip, Mt Hagen Sub-district , 1219 m, 5°36’S, 144°42’E, 25 January 1969, Hainsworth 90 ( LAE!) GoogleMaps ; Kubor Range, Nona-Minj Divide, Uinba , 1950 m, 5°54’S, 144°41’E, 7 September 1963, Vink 16507 (A, K!, L!) GoogleMaps ; Mt slope named Andem, Nondugl , Banz Subdistrict , 1829 m, 5°50’S, 144°45’E, 30 July 1971, Zieck NGF 36254 View Materials (BH, L!, LAE) GoogleMaps ; Noltubi , NE of Melip Village, Minj District, 1900 m, 5°54’S, 144°41’E, 23 February 1981, Vinas 3946 (L, LAE!, UPNG) GoogleMaps ; Nondugl, Kaming Village, Banz Sub-District , 1829 m, 5°50’S, 144°45’E, 30 July 1971, Zieck NGF 36253 View Materials (BH, BRI!, CANB, L!, LAE) GoogleMaps ; Nondugl, Minj subdist, 1981 m, 5°50’S, 144°45’E, 16 February 1965, Millar NGF 23852 View Materials (BH, L!, LAE) GoogleMaps . Western Province: North Fly District, road from Tabubil to Ok Tedi copper mine, 8.5 km N of Tabubil, ca. 2 km NW of Finalbin , 1000 m, 5°12'31"S, 141°10'42"E, 12 December 2000, Baker et al. 1131 ( AAU!, K!, LAE!, NY!) GoogleMaps .

Notes:— It is remarkable that this widespread and apparently rather useful rattan has not been described previously. Calamus oresbius ( Fig. 9 View FIGURE 9 ) is a variable, yet distinctive, slender, flagellate species that is characterised by its short leaves (up to ca. 54 cm long) with 3-6 pairs of leaflets, which, in most forms, are arranged in two widely spaced groups, one clustered at the apex and one or two pairs grouped at the base. The leaflets are broadly elliptic to oblanceolate and leathery, the apical pair being fused for one fifth to half their length. Its inflorescence is narrow and flagelliform, with fine rachillae, and is branched to two orders (or scarcely to three orders in some staminate material). There is some variation in leaflet arrangement, leaf sheath armature and overall stature, with some apparent differentiation into regional forms, though these are not recognised taxonomically here.

Calamus oresbius might be confused with Calamus johnsii , which occurs at much lower elevation and is easily distinguished by its relatively robust inflorescence, or Calamus anomalus , which is similar in stature and leaflet arrangement, but has unique inflorescence morphology. “ Oresbius ” is an infrequently used epithet meaning “mountain-dwelling” ( Stearn 1992).


Addis Ababa University, Department of Biology


Queensland Herbarium


Papua New Guinea Forest Research Institute


Australian National Botanic Gardens


Kyoto University


University of Papua New Guinea