Calamus tetradactylus Hance, J. Bot. 13: 289 (1875)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Cambodiapresent (World Checklist of Arecaceae)B
China South-Centralpresent (World Checklist of Arecaceae)B
Hainanpresent (World Checklist of Arecaceae)B
Laospresent (World Checklist of Arecaceae)B
Thailandpresent (World Checklist of Arecaceae)B
Vietnampresent (World Checklist of Arecaceae)B
DISTRIBUTION. China (Yunnan, exact location unclear, and South-east China), Thailand (East and South-east), Laos (Central and South), Vietnam (all except North Annam) and Cambodia. (T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002)A

Discussion

  • When Conrard (in Gagnepain & Conrard 1937) cited only Bon 3549 in naming C. tetradactylus var. bonianus he implicitly made this the lectotype. Although Conrard attributed the variety to Beccari it is more correctly cited as shown, since Beccari published the name at another rank. Beccari (1910) diagnosed C. cambojensis on the basis of its 'slender and flaccid spadix with narrower, longer and more closely sheathing spathes' and C. bonianus by its 'denser partial inflorescences with more spikelets and these with more flowers' and also by the sessile involucrophore and possibly smaller fruit (although these latter he had only seen immature). He mentioned that C. bonianus may well be only a local form of C. tetradactylus. Extensive new material has allowed a reassessment of the various forms. Calamus bonianus is certainly synonymous with C. tetradactylus. Calamus cambojensis is perhaps more distinctive since material from Cambodia, Kontum Province (Vietnam) and southernmost Laos shows inflorescences where (with the slight exception of Evans, T 59) all primary branches are well exserted from their bracts and so all primary bracts, including the first, are tightly sheathing, whereas the material from elsewhere in Vietnam and China shows one or more of the more proximal primary bracts inflated (always including the most basal) because their corresponding primary branches are inserted within them. However, both types of inflorescence can be seen in the material from Sisaket Province (Thailand) and in view of the obvious variation in the expression of this character (perhaps related to environmental factors governing the exact rate of extension of the inflorescence), together with the great number of other details which are similar between plants from these two areas, we prefer to place all of them in a single, variable species. There may be an argument for recognising two subspecies. However, before doing so it is important to note that variation occurs in several other characteristics, especially around the Annamite mountain chain south of about 18'N. The following examples suggest that further taxa may need to be named in this economically important group once more material and field observations have been collected in this region: 1) plants from one locality in Bolikhamxay Province (Laos) have unusually small leaflets with smooth margins and a strangely 'pinched', acuminate tip, as well as pronounced orangey scale margins on the dry fruit (Oulathong 207, 208 and 209). 2) some plants from Champassak Province (Laos) are particularly robust with broad leaflets drying green and long partial inflorescences (up to 35 or even 40 cm) (e.g. Klackenberg, J. 1090 and 1327, Khamphone 410), whilst others (e.g. Evans, T 59) are more delicate and dry bright yellow. 3) the material from South Annam and Cochinchina (Vietnam) has a waxy coating on the abaxial surface of the leaflets that is thick, floccose (when viewed under 30x magnification) and whitish, almost sufficient to be described as whitish indumentum, and the involucrophore is noticeably pedicelliform (e.g. in Poilane 21614, 21718, 22271 and 23814). 4) some plants bear a curious comb of flexible spines at the sheath mouth, even though the rest of the sheath is sparsely armed (e.g. Averyanov, L. 1525). The involucre on the male plant varies from specimen to specimen between almost discoid and quite deeply cupular, and the rachilla axis of the male plant also varies in thickness. There is a wide range of leaflet sizes, even in Tonkin and south- east China. The longest leaflet on a leaf ranges from 11 to 31 cm in the specimens seen, with most values in the range 14 - 26 cm. Except for the Central Lao specimens all have bristly margins and most have the leaflet surfaces naked, but occasional bristles occur on the middle vein on plants throughout the species' range. The fact that some specimens dry yellow may not be significant - there are two fully fertile and apparently identical sheets of Clemens, J. & M. S. 3100 in BM and of these one has dried uniformly bright yellow, the other uniformly mid-green. (T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002)A

Biology And Ecology

  • Evergreen forest and scrub at 100 - 1000 m. (T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002)A

Conservation

  • This widespread, common and widely cultivated species is unlikely to be under serious threat. If smaller localised taxa are recognised some of these may be under greater threat. (T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002)A

Common Name

  • wai hangnou, wai hangnounyai, wai savang (Lao Loum), kaceck doikanair (Phong), re peu (Alak), wai krit (Thailand). (T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002)A

Uses

  • The cane is of high quality and is probably important in trade, especially in Vietnam. Vu Van Dung & Le Huy Guang (1996) report that a species to which they give this name has been cultivated by smallholders around Hanoi for over 100 years and the practice is now spreading. This appears to be one of the oldest rattan cultivation systems known. (T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002)A

Materials Examined

  • CHINA (YUNNAN), no locality, undated, (fr.), Forrest, G. 12172 (K). (SOUTH-EAST): Hong Kong, undated, (pist.), Hance 18979 (K, P, BM). THAILAND (EAST): Sisaket Province, Kantaralak Distr., Dongrak Range, Chong Bat Lak, 19 Aug. 1976, (stam.), Maxwell,J. E 76 - 576 (BK) and (pist.), Maxwell, J. E 76 -580 (BK). (SOUTH-EAST): Korat, Kao Kanap, 26 Dec. 1929, (fr.), Kerr A. 17824 (K, BM, BK). LAOS (CENTRAL): Bolikhamxay Province, Pakkading Distr., Ban Naphong, Phou Tat Thone, 7Jan. 1999, (stam.), Oulathong OL 208 and (fr.), Oulathong OL 207 (FRCL, K). (SOUTH): Champassak Province, Pathoomphone Distr., Ban Xeng, near the road, 21 May 1999, (fr.), Khamphone KP 413 (FRCL, K). VIETNAM (TONKIN): West Tonkin, 'in sepibus Tai Kenh', 16 Nov. 1887, (fr.), Bon 3549 (P). (CENTRAI, ANNAM): Danang and vicinity, 1927, (pist.), Clemens, J. & M. S. 3100 (K, P, BM). (SOUTH ANNAM): Haut Donnai Province, near Blao Agricultural Station, Col de Braian, Phnom Sapoum, 10 Jan. 1935, (fr.), Poilane 23814 (K, P). (COCHINCHINA): Bien Hoa Province, 4 km N of Dinh Quanh, 4 Jan. 1933, (fr.), Poilane 21718 (P). CAMBODIA: locality unknown, undated, (pist.), Gorgaud s.n. E138 (P). (T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002)A

Bibliography

    A. T. Evans & K. Sengdala & B. Thammavong & O.V. Viengkham & J. Dransfield, A Synopsis of the Rattans (Arecaceae: Calamoideae) of Laos and Neighbouring Parts of Indochina. 2002
    B. World Checklist of Arecaceae