Dypsis anjae Rakotoarin. & J.Dransf., Kew Bull. 65(2): 290 (2010)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Madagascarpresent (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A
East of Madagascar, known only from buffer zone of Zahamena Natural Reserve in the area of Vavatenina. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Habitat

  • Humid lowland forest with closed canopy, on gentle slopes; 580 - 600 m. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Discussion

  • Belonging to informal Group 8, superficially Dypsis anjae seems similar to D. delicatula and D. pulchella; the former has extremely slender short and numerous rachillae, very different from the rather far fewer and more robust rachillae of D. anjae while D. pulchella has a more deeply cleft leaf and more numerous, more robust and longer rachillae. It is one of the smallest palms in Madagascar. The species is named for the first collector of this palm, Anja Byg. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Diagnosis

  • Dypsis delicatulae Britt & J. Dransf. et D. pulchellae J. Dransf. verosimiliter affinis; a D. delicatula inflorescentia rachillis paucioribus robustioribus et a D. pulchella folio minus profunde fissa et rachillis pauciorbus et robustioribus differt. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Conservation

  • Critically Endangered [CR, B1a+b(iii)]. Known only from the buffer zone of Zahamena Natural Reserve, in an area calculated as 17.8 km2. Although this species occurs in a protected area, its habitat may be disturbed sporadically by the incursion of local villagers looking for wood and other forest products. (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Common Name

  • Sinkaramboalavo (Betsimisaraka). (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Description

  • Slender clustering or occasionally solitary palm. Stems to 3 m high, c. 5 - 10 mm diam., internodes 0.8 - 4 cm long, dark green with caducous black scales. Leaves entire bifid, 6 - 15 in the crown, spreading; sheaths 6 - 7 cm long, open for 1 - 1.6 cm in the distal part,forming a short crownshaft, pale green, with reddish scattered scales, auricles narrow, c. 0.8 × 0.6 mm; petiole 0.9 - 4.5 cm long, c. 2 mm diam., sparsely to densely scaly; blade leathery, obtriangular, 15 - 27 cm long, 3 - 4.8 cm wide, dark green; midrib 11 - 21 cm long, lobes 4.2 - 10 × 2 - 2.8 cm, main veins 5 - 10, apices minutely dentate. Inflorescence interfoliar, branched to 1 order; peduncle c. 9.5 cm long, c. 2 mm diam., glabrescent; prophyll 6.5 cm long, 0.6 cm wide, split in the distal 2 cm, glabrescent; peduncular bract persistent, 9.4 cm long, glabrous, purplish to brown, inserted at 4.3 cm from the base of peduncle, split for 3.6 cm in the distal part; rachis 2.4 cm, puberulous at anthesis but glabrous in fruit; rachillae c. 5 2.5 - 4 cm long, 0.8 - 1.2 mm thick, triads distant, flowers yellow. Staminate flowers with sepals 1.5 - 1.9 × 2 - 3 mm, imbricate, keeled, asymmetric; petals 4.5 - 7.2 × 2.3 - 3.8 mm, elliptic, imbricate; stamens 6, uniseriate, filaments c. 0.3 mm; anthers medifixed, versatile, elongate, 2.4 - 2.8 × 0.7 - 1 mm; pistillode c. 1.1 × 0.7 mm. Pistillate flowers with sepals imbricate, 2.1 - 2.7 × 3 - 3.2 mm; petals elliptic, beaked, imbricate, minutely puberulous, 4.2 - 4.8 × 2.7 - 3 mm; gynoecium 4.2 - 4.8 × 2.7 - 3 mm. Fruits reddish, ellipsoid, curved at the apex, 5.2 - 5.5 × 2.1 - 2.2 mm, mesocarp fibrous, stigmatic remains sub-basal. Seeds ellipsoid, curved, c. 4.3 × 1.7 mm, embryo lateral, endosperm homogenous (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Materials Examined

  • MADAGASCAR. Toamasina, Vavatenina, RNI Zahamena, 17°40'S, 49°00'E, 16 Oct. 1998, A. Byg 16 (fl.) (AAU, K); idem 17°39'10"S, 48°58'07"E, 24 Oct. 2002, L. J. Razafitsalama et al. 146 (fr.) (holotype K!; isotypes CNARP!, MO!, P!, TEF!). (M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010)A

Bibliography

A. M. Rakotoarinivo & J. Dransfield, New species of Dypsis and Ravenea (Arecaceae) from Madagascar in Kew Bulletin 65. 2010