Calamus croftii W.J.Baker & J.Dransf., Phytotaxa 163(4): 191 (2014)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Papua New Guineapresent (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A
Known from lowland forest in Morobe and Oro Provinces, Papua New Guinea. (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Habitat

  • Lowland forest up to about 150 m above sea level. (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Diagnosis

  • Distinguished by the slender stems, sheaths lacking a well-developed ocrea and rather densely covered with horizontal spines, the leaves with irregularly arranged lanceolate leaflets and the large pointed fruit borne on short, rather lax, zigzag rachillae. (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Common Name

  • None recorded. (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Etymology

  • This rattan is named for Jim Croft, currently of the Australian National Herbarium and prolific collector of many plants during his 15 years stationed at the Papua New Guinea National Herbarium. (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Uses

  • None recorded. (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Description

  • Slender rattan, climbing to 30 m or more, whether solitary or clustering not recorded. Stem with sheaths 10-15 mm diam., without sheaths to 6-8 mm diam.; internodes 15-31cm. Leaf ecirrate, 60-75 cm long; sheath drying dull greenish brown, with abundant, caducous, woolly, pale grey indumentum, sheath spines abundant, persistent, uniformly distributed, of varying length, 3-27 × 1-2 mm, horizontal, shiny straw-coloured with black tips, often edged with woolly indumentum, spines around the leaf sheath mouth crowded, similar in form to those on the sheath; knee conspicuous, to 40 × 4 mm, drying same colour as sheath, armed as the sheath; ocrea to 10 mm long, armed as the sheath; flagellum present, 1.25 m long; petiole 10-15 cm long, 5-7 mm wide at the base, adaxially flattened, unarmed, abaxially rounded, bearing caducous white indumentum and armed as the sheath; rachis to 65 cm long, adaxially unarmed, abaxially armed with recurved hooks; leaflets 4-8 on each side of rachis, irregularly arranged, usually in 2-4 groups, but sometimes groups scarcely evident, broadly lanceolate with acute tips, longest leaflet in mid-leaf, basalmost leaflets 17-28 × 3-4.5 cm, mid-leaf leaflets 23-30 × 4.5-5.5 cm, apical leaflets 9-14 × 2-2.5 cm, apical leaflets joined for one third of their length, leaflets armed with sinuous black bristles to 3 mm long along margins near the tip, otherwise unarmed, leaflets lacking indumentum, transverse veinlets conspicuous. Staminate inflorescence to at least 70 cm, apparently lacking a terminal flagellum, branched to 3 orders; prophyll to 25 cm long, coriaceous, basally closely tubular, distally with an expanded triangular limb to 2.5 cm long, very sparsely armed; peduncular bracts absent; rachis bracts similar to prophyll, very sparsely armed, somewhat inflated; primary branches at least 3, to 12 cm long, with numerous rachillae; rachillae to 10-30 × 0.8 mm diam.; rachilla bracts rather distant, 2 × 1 mm, distichously arranged, not overlapping, striate, with apiculate recurved tips and scattered brown indumentum, unarmed; floral bracteole explanate, 1.2 mm wide, unarmed. Staminate flowers 4.5 × 2.5 mm; calyx 3 × 2.5mm, with short triangular lobes to 1 mm high; petals 4 × 1.5 mm; stamens 3 mm long, anthers 2 × 0.3 mm. Pistillate inflorescence to 1 m long, including peduncle 27 cm, branched to 2 orders, apparently lacking a terminal flagellum; prophyll to 27 × 1.2 cm, sparsely armed with spines to 4 mm; peduncular bracts absent; rachis bracts similar to prophyll, to at least 21 × 0.6 cm, sparsely armed; primary branches 4, to at least 15 cm long, with up to 10 rather distant rachillae; rachillae more or less zigzag and recurved, the basal ones the longest, to 30 × 1.5 mm, rather lax, bearing up to 5 female flowers; rachilla bracts triangular, 1.5 × 2 mm, distichous, not overlapping, with short triangular tips, unarmed, bearing scattered brown indument; proximal floral bracteoles explanate, ca. 2 mm diam, distal floral bracteoles explanate, ca. 1.5 mm high, scar from sterile staminate minute, 0.1 mm diam. Sterile staminate flower not known. Pistillate flowers not known. Fruit pyriform, pointed, 23 × 13 mm, with a beak to 1.5 × 1.5 mm, and with ca. 16 vertical rows of mid-brown scales with darker margins. Seed 13 × 8 × 7 mm, with a very deep groove on one side, seed surface smooth, endosperm homogeneous, embryo basal. (Fig. 5) (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Materials Examined

  • PAPUA NEW GUINEA. Morobe Province: Natter Bay logging area, 93 miles SE of Lae, 150 m, 7°31'S, 147°21'E, 26 July 1976, Croft & Lelean LAE 68504 (LAE!). Oro Province: Popondetta Subdistrict, Ehu, (New Kikinota), Kumusi Timber Permit Area, 50 m, 8°27'S, 148°14'E, 31 January 1973, Zieck NGF 36542 (holotype L!, isotypes BH, CANB, K!, LAE). (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Notes

  • This poorly known rattan (Fig. 5), recorded from only two localities, is recognised by its slender stems, leaf sheaths that are rather densely covered with horizontal, triangular spines, ecirrate leaves with irregularly arranged lanceolate leaflets and, most conspicuously, by the large pointed fruit widely spaced on short, zigzag rachillae. It most closely resembles C. lucysmithiae, but this species bears a well-developed, divergent ocrea and much smaller fruit that are densely crowded on strongly recurving rachillae. (W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014)A

Bibliography

    A. W.J. Baker & J. Dransfield - New rattans from New Guinea (Calamus, Arecaceae) in Phytotaxa. 2014