Dypsis beentjei J.Dransf., Palms Madagascar : 401 (1995)

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Content

Introduction

  • This beautiful species is immediately recognizable by its stemless habit and dark green bifid leaves, each with a central pale yellow line. So far it is known only from an area of forest developed on supposed ultramafic rock in the Biosphere Reserve south of Mananara Avaratra. Here it grows in a valley bottom, in damp hollows and along small streams. It would make a handsome ornamental. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Distribution

East Coast. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Discussion

  • This unusual species is immediately recognisable by its acaulescent habit and relatively large entire bifid dark green leaves, each with a central pale yellow band. The inflorescence is sparsely and divaricately branched and is partially hidden among leaf litter on the ground. Apart from being obviously allied to other species with three antepetalous stamens, its relationships are not clear. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Diagnosis

  • Acaulescens folio bifido atroviride, linea media albo-lutea, inflorescentia sparse divaricate ramosa floribus staminatis triandris, staminibus antepetalis staminodiis antesepalis alternantibus. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Biology And Ecology

  • Rain forest, waterlogged alluvial flat beside river, ultramafic bedrock; c. 250 m. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Conservation

  • Endangered. Although known from a single population, this does occur within the Biosphere Reserve. However, we have seen no more than about thirty plants. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Common Name

  • Not recorded. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Uses

  • Not recorded. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Description

  • Clustering acaulescent palm with stems subterranean and procumbent, forming tufts in the forest undergrowth. STEM c. 4 x 1.4 cm, dull brown, bearing robust roots c. 2 mm diam. Leaves c. 9 in crown, ± erect; sheath 7-9 cm long, 2.5-3 cm wide at the base when opened out, pale creamy brown, tinged reddish when fresh, drying reddish brown, with a conspicuous central pale yellow line, the sheath striate on drying, densely covered with caducous dark brown scales; petiole to 55 cm long or more, c. 4 mm wide, ± triangular in cross section, pale creamy brown, covered in caducous dark brown scales; lamina narrow-triangular, entire-bifid, to 60 cm long, c. 10 cm wide across the two tips, apically cleft to 19 cm, the lobes to 3.5 cm wide at the base, tapering to the shallowly lobed tip, 0.5 cm wide, the lamina base long decurrent on the petiole, lamina leathery in texture, adaxially dark shining green when fresh, with scattered minute punctiform dark brown scales, the mid-line pale creamcoloured, abaxially matt, bearing rather dense apparently caducous dark brown scales of varying size with laciniate margins, particularly along the ribs. INFLORESCENCE interfoliar, erect at first, becoming curved, branching to two orders, ± rectangular in outline; peduncle to 25 cm long, 3 mm diam., rounded in cross-section, densely covered in dark brown laciniate-margined scales; prophyll to 8 x 0.5 cm, membranous, soon tattering, bearing scattered dark brown scales; peduncular bract long exceeding the prophyll, to 18 x 0.5 cm, membranous, soon tattering, scaly as the prophyll; rachis to 9 cm long, scaly as the peduncle; lowermost 3-4 branches branched with one branch of the second order; rachillae 15-20, 3-5 cm long, c. 6 mm diam., somewhat zigzag, the triads 2-6 mm distant, each sub-tended by a lacinate rachilla bract to 1.5 x 0.5 mm, the rachilla surface partially obscured by dark brown laciniate scales. STAMINATE FLOWERS at anthesis pale green, depressed spherical, 2 x 2.5 mm; sepals rounded and gibbous at first, to c. 1 x 1 mm, then becoming explanate and splitting irregularly into 3 sections; corolla spherical, tubular at the base, lobes gaping at anthesis; stamens 3 free, antepetalous, alternating with 3 antesepalous staminodes; staminodes wedge-shaped, succulent, 0.9 x 0.8 mm; fertile stamens with succulent filaments 1.0 x 0.5 mm, connective dark, 0.3 x 0.3 mm, anthers didymous, 0.5 x 0.3 mm; pistillode pyramidal c. 0.4 mm high. PISTILLATE FLOWER buds very immature, c. 1 mm diam. Mature FRUIT scarlet, irregularly ovoid to ellipsoid, to 17 x 10 mm; epicarp glabrous; mesocarp soft, fleshy; endocarp ellipsoid, 12 x 6 mm, c. 0.2 mm thick, withlongitudinal brown fibres, irregularly anastomosing. SEED irregularly ellipsoid, 9-10 x 5 mm, shallowly longitudinally grooved; endosperm homogeneous, embryo lateral. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Materials Examined

  • Mananara Avaratra: 10 km west of Antanambe, Oct. 1991 (fl.), Beentje 4475 (K, TAN); idem, April 1992 (fl.,fr.), Beentje & Dransfield 4626 (Holotype K; isotypes BH, MO, P, TAN ). (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Bibliography

    A. Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar