Dypsis betsimisarakae Rakotoarin. & J.Dransf., Kew Bull. 65(2): 293 (2010)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Madagascar present (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A
East of Madagascar, between Soanierana Ivongo and Anosibe an'Ala. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Habitat

  • Lowland and middle altitude forest, steep slopes under more or less open canopy; 300-750 m. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Discussion

  • This species would key to Dypsis nodifera, because of its size, the ruminate endosperm and irregularly arranged leaflets. However, the habit is almost always clustering rather than solitary and the leaflets are linear rather than usually lanceolate, and usually lack the strong swelling at the leaflet bases. Furthermore, the leaflets are not twisted at their bases to be displayed in several planes, and the palm thus has an altogether different appearance. The species epithet is based on the name of the ethnic group of people who live in the general area of the palm?s distribution. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Diagnosis

  • Endospermio ruminato D. nodiferae affinis sed habitu caespitoso foliolis linearibus basin vix nodosis differt. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Conservation

  • Vulnerable [VU (B1a+b(i,ii, iii, v); C2a)]. Large distribution range (EOO: 9880 km2) but known only from five locations where almost all of the habitat is subject to human pressure. The species is losing its habitat (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Description

  • Clustering palm with 2-5 stems or rarely solitary.Stems 2 -6 m tall, 1.5- 3 cm diam., leaning, internodes 1.6-7 cm long, pale green to grey. Leaves 6- 9 in the crown, porrect; sheath 19- 30 cm long,1.8- 3.2 cm wide, closed, forming a well defined, often bulbous crownshaft, pale green or grey, covered with red scales, auricles triangular 2.6- 5.5x 0.3- 1.2 cm; petiole absent or up to 21 (47) cm long, proximally 4-7 x 3- 5 mm across, distally 5-7x 2.3-3 mm across, densely scaly, adaxially flat or shallowly channelled; rachis 50- 107 cm long, in mid-leaf 2- 4 mm wide, abaxially with scattered scales, adaxially keeled; leaflets 16 -26 on each side of the rachis, grouped or irregular, linear, mostly arranged in the same plane, in groups of 3-6, groups at intervals of 6- 13 cm, leaflets within the group at intervals of 0.4 . 1.5 cm, rarely swollen at the base, proximal leaflets 12- 24x 0.2- 0.6 cm, median leaflets 21- 30 x 1.7- 2.8 cm, distal leaflets 10.5- 12.5 ?x 1.2-2 cm, glabrous, apices to 12 cm long, main veins 1- 5. Inflorescence infrafoliar, branched to 2 (. 3) orders; peduncle 10- 18 cm long, 0.4-1 cm wide, scaly; prophyll 6.5-16 cm long, 1.3-1.8 cm wide, keeled, borne at 1.2- 4 cm above the base of peduncle, split in the distal 2.6- 5 cm, scaly; peduncular bract inserted at 4-10.5 cm from the base of peduncle, 21-32 cm long, split in the distal 14- 25 cm, minutely scaly, beak 1- 1.5 cm long; rachis 15- 20 cm long, scaly or rarely glabrous, with 6-8 branched and 7-9 unbranched first order branches; rachillae 11-29 cm long, c. 1.5 mm diam., glabrous, pendulous, triads distant. Staminate flowers with imbricate sepals, 1.8- 2.2x 1.8- 2.5 mm, irregular clefts in the margins; petals obovate, valvate, not striate, fleshy, 1.6-1.9x 1.4-1.6 mm; stamens 6, biseriate, antesepalous lower than antepetalous, filaments 0.4-0.7x 0.2-0.3 mm, anthers 0.5- 0.7 mm long, dorsifixed, locules divergent, versatile; pistillode minute, c. 1.5 mm high. Pistillate flowers with sepals 1.3-1.5x 1.8-2 mm, keeled ,± irregular, petals 2.2-2.4 x 1.7-1.8 mm, obovate, fleshy; gynoecium c. 2.2 ?x 1.6 mm. Fruits ellipsoid, red, 0.7-1.1x 0.4-0.5 cm, mesocarp fibrous. Seed ellipsoid, 7--8x 3-4 mm, endosperm deeply ruminate. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Materials Examined

  • SPECIMENS EXAMINED. MADAGASCAR. Toamasina: Soanierana Ivongo, Ambatovaky reserve, 16º48'04"S, 49º10'21"E, 11 Dec. 2003, A. Britt et al. AB45 (K!, TAN!); idem 16º49'06"S, 49 º11'12"E, 15 Dec. 2003, A. Britt et al. AB53 (holotype K!; isotype TAN!); idem 16º48'23"S, 49º10'33"E, 10 Dec. 2003, H. Beentje 4913 (K!, TAN!), idem 16º50?43?S, 49º10?54?E, 14 Dec. 2003, H. Beentje 4940 (K!, TAN!), idem 16º47'06"S, 49º10'48"E, 15 Dec. 2003, J. L. Razafitsalama 561 (K!, TAN!). Soanierana Ivongo, Befanjana, 16º40'11"S, 49º36'12"E, 14 Sept. 2006, M. Rakotoarinivo et al. 243 (K!, P!, TAN!) & M. Rakotoarinivo et al. 245 (K!, TAN!). Brickaville, Reserve speciale Mangerivola, Andramangarana, 18º12'22"S, 48º55'29"E, 21 July 2006, M. Rakotoarinivo et al. 223 (K!, P!, TAN!). Anosibean'ala, Andonabe, 19º19'39"S, 48º06'30"E, 16 June 2006, M. Rakotoarinivo et al. 199 (K!, P!, TAN!). (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Bibliography

    A. M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303