Calamus bousigonii subsp. smitinandii J.Dransf., Kew Bull. 55: 713 (2000)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Thailand present (World Checklist of Arecaceae)A

Discussion

  • Calamus bousigoniii subsp. smitinandii differs from typical C. bousigonii in the inflorescence rachis bracts and fruit shape. In C. bousigonii subsp. bousigonii the rachis bracts are strictly tubular and for the most part intact, not splitting, and the first order branches are inserted at the mouth of the bracts. In C. bousigonii subsp. smitinandii, the rachis bracts are elongate and they split for at least half their length, opening out and becoming flattened and tattering, and the first order branches are inserted about half way along the length of the bracts. These differences give the inflorescence a distinctive appearance, somewhat reminiscent of inflorescences of species in Furtado's section Platyspathus, rather than section Rhombocalamus. The fruit of subsp. smitinandii is uniformly rather narrow ellipsoid rather than broadly ovoid as in subsp. bousigonii. Fruit scales in the former are arranged in 20 vertical rows and are approximately 1.5 x 1.5 mm whereas those of the only fruiting specimen of subsp. bousigonii are arranged in 18 vertical rows and are approximately 2 x 1.5 mm. However, these last fruit scale differences may not be significant. Calamus bousigonii subsp. smitinandii is one of the most attractive of all Thai rattans. Its glossy undulate diamond-shaped leaflets and its neat low habit give it considerable horticultural potential. Among Thai species it is very distinctive. The only other taxon with diamond-shaped leaflets in Peninsular Thailand is C. blumei. This is altogether different, being a high-climbing taxon that is rarely found fertile, distinctive in its leaf sheaths densely covered in a thick indument of silvery or golden hairs and chocolate brown scales, with generally scattered very short black spines that are often upward pointing and often borne on rounded bulbous swellings. The inflorescences of the precociously flowering C. bousigonii subsp. smitinandii, almost always found flowering at a mere 2 - 3 m tall, is immediately distinguishable based on the elongate expanded and tattering peduncular and rachis bracts. This new subspecies was figured erroneously as C. blumei in Hodel et al. (1998) while his figures of C. tomentosus almost certainly refer to C. blumei. The subspecies is named for Tem Smitinand, 1920 - 1995, Thai botanist extraordinary, who often gave me much encouragement in my studies of Thai palms. (J. Dransfield, Calamus bousigonii. 2000)B

Diagnosis

  • A varietate typica bracteis primariis inflorescentiae longis fissis laminam conspicuam facientibus vice valde tubulosis integris, ramis primariis inflorescentiae aliquantum infra orem bracteae insertis vice ad orem insertis, fructibus ellipsoideis vice ovoideis distincta. (J. Dransfield, Calamus bousigonii. 2000)B

Description

  • Slender clustering rattan climbing to 10 m (rarely to 20 m), often flowering and fruiting at 2 - 3 m tall. Stem without sheaths 4- 8 mm diam., with sheaths 5 - 16 mm diam.; internodes 6 - 10 cm long. Leaves ecirrate; leaf sheath rather densely covered in solitary narrow triangular spines 1 - 13 mm long, with slightly to strongly swollen bases, the spines generally drying the same colour or slightly paler than the sheath surface, thin scattered caducous pale brown tomentum present between the spines; knee well developed to c. 4 mm high, tending to be unarmed or more sparsely armed than the rest of the sheath; flagellum to 1.5 mm long; petiole 10 - 45 cm long, sparsely to densely armed with short black-tipped triangular spines with swollen bases adaxially, abaxially and along margins; rachis to 95 cm long, usually shorter, armed with scattered reflexed spines; leaflets rhomboid, 6- 8 on each side of the rachis, arranged regularly but rather distant, the apical pair divergent, shiny, dark green except at the insertion on rachis where pale, basal leaflets 10 - 20 x 3 - 7.5 cm, mid-leaf leaflets 14 - 23 x 4.5 x 8.5 cm, apical leaflets 11 - 14.5 x 2.5 - 6.5 cm, all leaflets with numerous veins radiating from the base, transverse veinlets conspicuous, margins slightly undulate bearing rather regularly arranged black spines. Inflorescences to 100 cm long including the terminal flagellum to 40 cm long, the staminate branching to 3 orders, the pistillate to 2 orders, with 2- 7 partial inflorescences; prophyll tubular at the base, splitting for about one half its length, becoming expanded and blade-like, tattering, sometimes empty, sometimes subtending a partial inflorescence, with scattered triangular spines and abundant mid brown tomentum; rachis bracts very conspicuous, similar to the prophyll but generally shorter, sometimes splitting almost to the base, unarmed, to c. 11 x 1 - 1.5 cm, often shorter; partial inflorescences inserted on the rachis about one third to one half way along the length of the subtending bract, with relatively few (2 - 7 in pistillate, up to 20 in staminate) distichous rachillae, the whole ? triangular in outline; rachillae ? straight or slightly curved, appearing zig-zag from the flower insertions, the staminate c. 10- 15 mm long, 1 mm diam., the pistillate to 30 mm long, c. 2 mm diam.; rachilla bracts c. 1 mm long, with a triangular limb to 1.5 mm long, with sparse tomentum and scales; involucre and involucrophore forming a flattened cup c. 2 mm diam.; involucropohore striate, ± rounded with two low triangular lobes. Staminate flower c. 5 x 1.75 mm; calyx striate, tubular in basal 2 mm, with triangular lobes to 1 x 1 mm; petals 4.5 x 1.5 mm, connate in basal 1 mm, smooth, as if almost polished, tipped and edged with dark brown; anthers 2.3 x 0.5 mm. Sterile staminate flower as the fertile but with empty anthers. Pistillate flower with calyx striate, tubular in basal 2 mm, c. 2 mm wide, lobes triangular acute, to I mm long; corolla exceeding the calyx, petals 3 x 1.8 mm, very thick, smooth and appearing almost polished; staminodal ring to 1 mm high, sterile anthers elongate 1.2 x 0.2 mm; ovary 3 x 1.8 mm, stigmas 1.1 x 0.3 mm, recurved. Fruit ellipsoid, 15 - 18 x 10- 11 mm, including beak 2 - 3 x 1 - 1.5 mm; scales arranged in 20 vertical rows, c. 1.5 x 1.5 mm, channelled, dull yellow-brown and sometimes with the distal half dark brown, narrowly bordered with dark brown, the tips obtuse. Seed 13 x 5 mm, ellipsoid, surface sparsely pitted; endosperm sparsely ruminate; embryo basal. (J. Dransfield, Calamus bousigonii. 2000)B

Materials Examined

  • THAILAND. Peninsular. Surat Thani, Khao Luang, c. 1100 m, 10 Aug. 1927, Kerr 13266 (K); Nakhon Si Thammarat: Khao Luang, alt. c. 900 m, 29 April 1928, Kerr 15465 (K); alt. 750 - 950 m, 22 May 1968, van Beusekom and Phengkhlai 930 (BKF, K, L); alt. 800 m, 25 Feb. 1991, Chawalit Niyomdham 2346 (BKF, K). Phatthalung, Kao Soi Dao, c. 700 m, 18 April 1930, Kerr 19444 (K). Trang: Khao Chong National Park, alt. 100 m, 18 April 1979, Dransfield and Bhoonab, JD5427 (BKF, K); 1970, Charoenphol et al. 3721 (AAU, BKF, K); alt. 50 - 400 m, 1982 - 85, Vongkaluang 120 (BK, K); rattan study plot above Peninsular Botanic Garden, 99048' E 07033', mixed evergreen forest, alt. 200 m, 3 Dec. 1993, Bogh 45177 (AAU, BKF, K, PSU). Satun: Talae Ban, Nature Trail leading away from the border with Malaysia, 100010' E 06042', alt. 100 - 150 m, 29 Sept. 1996, Barfod et al. 43817 (AAU, BKF, K); Talae Ban, 20 km NE of Satun, 100007' E 06045', alt. 100 - 150 m, 4 Nov. 1990, Barfod and Ueacharakan 41103 (AAU, BKF, K). (J. Dransfield, Calamus bousigonii. 2000)B

Bibliography

    A. World Checklist of Arecaceae
    B. J. Dransfield, Calamus bousigonii. 2000