Dypsis ankirindro W.J.Baker, Rakotoarin. & M.S.Trudgen, Palms (1999+). 53(3): 136 (2009)

Primary tabs

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Madagascarnative (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A
Northeast Madagascar, known from two mountains 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

  • Mountain summit vegetation, elfin forest and mountain thicket on quartzite, 650-950 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

  • This new taxon falls into Dypsis Group 3 (Dransfield & Beentje 1995). Other species from this group that occur in the same area include D. baronii, D. Oreophila and D. aff. serpentina. Of these, D. ankirindro is most similar to D. serpentina, but it more closely resembles D. andrianatonga, which is not yet recorded from Makira. However, both of these species have somewhat floppy, snaking stems that branch aerially, in contrast to the erect, unbranched habit of D. ankirindro. The new species also has somewhat broader elliptic leaflets, compared to the rather narrowly elliptic or linear leaflets of the other two species, as well as inflorescences that appear somewhat more robust. In addition, Dypsis serpentina has irregular or grouped leaflets, while D. ankirindro has regular leaflets, and D. andrianatonga has interfoliar inflorescences compared to the infrafoliar inflorescences of D. ankirindro. We have observed a degree of variability in D. Ankirindro in leaf morphology that may correspond with altitude. We acknowledge that distinguishing species in this group can be problematic and it is possible that species limits may be reconsidered when further new material becomes available. As a practical solution, however, we formally recognize this entity here to account for the new morphological dimensions that we have observed in the field. (M. Rakotoarinivo, M.S.Trudgen & W.J.Baker, The Palms of the Makira Protected Area, Madagascar in Palms (1999+) 53(3). 2009)A

Diagnosis

  • A D. andrianatonga caule non ramificanti inflorescentiis infrafoliaribus 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

  • Vulnerable [VU (D2)] (provisional assessment). Populations restricted to the summit of mountains in the central eastern part of Makira (Ankirindro and Beanivona), numbers of individuals are low and the area of occupancy is small. Nevertheless, isolation, difficult access and protection of its habitat decrease the risk of extinction of this species currently. (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

Description

  • Clustering palm. Stem to ca. 5 m high, erect, ca. 2-3 cm diam., internodes 2-3.6 cm, green with corky warts. Leaves 5-7 in the crown, spiral, erect, crown shuttlecock-like; sheath 25-32 cm, ca. 3.5 cm diam., closed, forming well-defined crownshaft to 50 cm long, green with scattered dark scales and black indumentum towards apex and grey bloom when young; petiole ca. 30 cm long, 6-7 mm wide, sparsely to densely black/brown scaly, sometimes with thin grey indumentum, adaxially channeled; leaf rachis ca. 60 cm long, 4-6 mm wide at mid point, triangular in section, indumentum/scales as rachis; leaflets narrowly to broadly lanceolate, leathery, single-fold, sometimes narrowly tapering, 10-20 on each side of the rachis, regularly arranged, ascending slightly then tips drooping, inserted 8-14 cm apart, proximal leaflets 35-72 × 0.5-2.5 cm, median leaflets 37-56 × 2.6-3.5 cm, distal leaflets 6-18 × 0.6-1.5 cm, sparsely to quite densely dark scaly on both surfaces, scales more abundant towards base and on abaxial surface, few medifixed ramenta on abaxial surface of midrib. Inflorescence infrafoliar, branched to 1 order; peduncle 9-12 cm long, ca. 0.8 cm wide, glabrous or with scattered scales; prophyll 9.5-10.5 cm long, 2-2.5 cm wide, borne 1-2 cm above the base of peduncle, 2- keeled, opening apically, persistent; peduncular bract 20-26 cm × ca. 4 cm, cucullate, opening longitudinally, persistent, inserted at ca. 4 cm from the base of the peduncle; rachis 3.5-7.5 cm long, with scattered scales, with ca. 9 rachillae; rachillae 10-17 cm long, up to 8 mm diam. at widest point, indumentum as rachis, rachilla bracts conspicuous, triads quite closely spaced. Staminate flowers 8-9 × 11-13 mm at anthesis, sepals 3, 4 × 4-4.5 mm, imbricate, cucullate, thick, with angular abaxial ridge, petals 3, 3.5-4.5 × 4-4.5 mm, valvate, triangular, stamens 6, erect, recurving, filament 6-7 × ca. 1.5 mm, flattened, briefly united basally, anthers medifixed ca. 3 × 1.5 mm; pistillode 2-3 × 1-1.5 mm, pyramidal; Pistillate flowers immature, bud ca. 4 × 6 mm, ovoid, perianth imbricate, staminodes 6, to 2 mm long, gynoecium 5 × 3 mm, ellipsoid. Fruits not seen. Seeds 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: just below summit of Ankirindro, May 2007, Baker et al. 1329 (holotype K, isotype TAN); summit of Beanivona, May 2007, Rakotoarinivo et al. 340 (K, TAN, MO). (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