Dypsis culminis Rakotoarin. & J.Dransf., Kew Bull. 65(2): 288 (2010)

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Distribution

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

Habitat

  • Lowland humid forest, only on higher slopes and ridge crests; 600 m. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Diagnosis

  • inflorescentia et floribis staminatis D. procumbenti (Jum. & H. Perrier) J. Dransf., Beentje & Govaerts verosimiliter affinis sed foliis bifidis vice pinnatis differt. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Conservation

  • Critically Endangered [CR (B2a+b(ii,iii); D)]. Rare species, only two mature individuals have been seen on a single mountain ridge where the forest on the lower slopes is being cleared. NOTES. This new species has an inflorescence and staminate flowers comparable with those of Dypsis procumbens but it differs from this latter in its entire bifid leaves. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Description

  • Clustering undergrowth palm with 4-8 stems. Stems to 3 m tall, 1.4- 2 cm diam., internodes 12- 30 mm, brown, covered in scattered reddish-brown pubescence in the distal part. Leaves 9-12 in the crown; sheaths 11- 13 x 1.3- 1.5 cm, longitudinally striate, covered in sparse to dense red-brown scales, crownshaft well defined, leaf sheath split to 4 . 6 cm distally, auricles triangular, 2.6- 3.3 ?x 0.2- 0.6 cm; petiole 3.2- 10 cm long, sparsely scaly, deeply channelled on the adaxial surface; rachis 49- 54 cm long, brown to pale yellow, minutely scaly; leaf blade entire bifid, 59 - 64 × 8.8 - 9.5 cm with an apical notch 7 - 9.5 cm, apex toothed, lamina leathery, abaxially covered in thin grey scales and very few small ramenta, main veins numerous. Inflorescence interfoliar, erect, branched to 1 order; peduncle 28 - 33 cm long, 3 - 5 mm wide, glabrous; prophyll c. 10 × 0.7 cm, brown, sparsely scaly, keeled, inserted at c. 2 cm from the base of the peduncle, open at 1.7 - 3 cm distally; peduncular bract persistent, c. 24 × 0.6 cm, minutely to densely scaly in the proximal part, inserted at c. 6 cm from the base of the peduncle, split to 3 - 4 cm in the distal part; rachis 7 - 16 cm long, pale green to yellowish, minutely puberulous; rachillae 6 - 9, yellowish, 7 - 13 cm long, c. 1 mm wide, with rather distant triads. Staminate flowers with imbricate sepals, 1 - 1.1 × 0.8 - 1.1 mm, keeled, margins erose; petals 1 - 1.2 × 0.7 - 0.8 mm, valvate, elliptic, striate; stamens 6, equal, filaments c. 0.2 mm, anthers medifixed, not versatile, c. 0.4 mm long, pistillode trilobed, c. 0.5 mm high. Pistillate flowers with imbricate sepals, 0.8 - 1.2 × 0.8 - 1.2 mm, slightly asymmetrical, keeled, margins minutely erose; petals 1-1.1 × 0.7 - 0.8 mm, valvate, striate, elliptic; gynoecium c. 0.5 × 0.4 mm, hexagonal. Fruits not seen. (M. Rakotoarinivo & Dransfield, J. 2010: New species of Dypsis and Ravenea (Arecaceae) from Madagascar. – Kew Bulletin 65: 279-303)A

Materials Examined

  • MADAGASCAR. Fianarantsoa,Vondrozo, Madiorano, 22°48 '15 "S, 47°16 '29"E, 28 Oct. 2006, M. Rakotoarinivo 335 (holotype K!; isotype 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