Dypsis brittiana Rakotoarin., Palms (1999+). 53(3): 138 (2009)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Madagascarnative (Palms (1999+). 53: 136 (2009))B
Northeast Madagascar, known from a single locality in the eastern central part of the Makira protected area. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Habitat

  • Primary rain forest, on ridge tops, ca. 900 m. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Discussion

  • Unfortunately, there is just one herbarium collection of this species. Nevertheless, it has been impossible to match it with any described species of Dypsis. In order to draw attention to it, we are describing it as new in the hope that more material will be collected. It is superficially similar to Dypsis procera and D. paludosa, but differs in its androecium. In D. brittiana, there are six didymous stamens whereas in D. procera and D. paludosa (Dypsis Group 13 of Dransfield and Beentje 1995) the androecium comprises three antesepalous stamens. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Diagnosis

  • Habitu et foliis D. procerae et D. Paludosae similis sed floribus staminatis 6 staminibus didymis vice 3 staminibus sagittatis differt. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Conservation

  • Critically endangered [CR (B1a)] (provisional assessment). This palm is known only from a single specimen collected at Tsaramainandro on the 2005 Makira expedition. This locality is just on the eastern boundary of the Makira protected area. It was not recorded again from any of the localities visited on the 2007 expedition. We infer from these limited data that D. brittiana is likely to be narrowly restricted in distribution and the provisional rating provided here is thus appropriate. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Common Name

  • Not recorded. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Etymology

  • Dypsis brittiana is named for Adam Britt, former colleague at Kew, who conducted the first palm exploration of Makira with Franck Rakotonasolo, during which this new species was discovered. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Description

  • Slender palm. Stem to 3 m tall, ca. 1.5 cm diam. Leaves 4-8 in the crown; sheath ca. 13-18 cm × 2.8 cm, forming a crownshaft, densely covered with red-brown stellate scales, open apically; petiole ca. 10 cm long, 4-5 mm wide, shallowly channeled to adaxially flat, abaxial surface covered of red brown scales; rachis ca. 14 cm, densely pubescent-scaly in the abaxial surface; blade entire-bifid, 54-60 × ca. 13 cm, lobe ca. 45 cm long, ca. 12 cm wide, main veins prominent, 10-12 in each side of the rachis, abaxial surface glabrous except for scattered ramenta 2.5-3 mm long, apex toothed. Inflorescence infrafoliar, erect to pendulous, branched to 2 orders; peduncle ca. 10 × 0.4 cm, densely puberulous; prophyll ca. 8.5 × 0.8 cm, keeled, borne at 0.8 cm above the base of peduncle, minutely scaly, opened in the ca. 2.3 cm of the distal; peduncular bract not seen, deciduous, borne at ca. 2 cm above the base of peduncle; rachis ca. 7.5 cm long, puberulous, with ca. 6 branched and 4 unbranched first order branches, the proximal with a rachis to 5.5 cm, slightly flattened, with 3-7 rachillae; rachillae 20-22 cm long, ca. 1 mm diam., red-brown, covered with trichomes, triads 0.8-1.2 mm apart. Staminate flowers sepals 1.1-1.2 × 1.1-1.4 mm, imbricate, asymmetric, keeled, minutely puberulous; petals 1.5-1.6 × 1-1.2 mm, valvate, striate, elliptic, coriaceous; stamens 6, didymous, filaments ca. 0.2 mm, anthers 0.3-0.5 × 0.5-0.6 mm, locules divergent, pistillode minute. Pistillate flowers measures from young bud: sepals 1.4 × 1.1-1.4 mm, imbricate, asymmetric, petals ca. 1.3 × 0.7, valvate, fleshy; staminodes 6, ca. 0.5 mm high; pistil ca. 0.7 mm high. Fruits not seen. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Materials Examined

  • Madagascar, Toamasina, Maroantsetra, Makira protected area, Ambinanitelo: Tsaramainandro, March 2005, Britt & Rakotonasolo 211 (holotype K, isotype TAN). (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Bibliography

A. M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009
B. Palms (1999+). 53: 136 (2009)