Ravenea beentjei Rakotoarin. & J.Dransf.

This species is accepted, and its native range is Madagascar.

[KBu]

Rakotoarinivo, M. & Dransfield, J. 2010. New species of Dypsis and Ravenea (Arecaceae) from Madagascar. Kew Bulletin 65: 279. DOI: https://doi.org/10.1007/s12225-010-9210-7

Conservation
Critically Endangered [CR(B2a + b(iii); D)]. Known only from one population in Vondrozo, where it is restricted to frequently flooded areas. In an Extent of Ocurrence estimated to be less than 7 km2, only about 40 mature individuals have been recorded in the field. The forest of Vondrozo is managed by the local community but logging operations still occur.
Distribution
Known only from Vondrozo forest, in southeast Madagascar.
Ecology
Common in lowland humid forest, in valleys and swampy areas; 600 – 650 m.
Morphology General Habit
Medium-sized, solitary, dioecious palm
Morphology Leaves
Leaves 8 – 15 in the crown, porrect to pendulous, arching, marcescent, occasionally trapping litter; sheath 50 – 90 × 10 – 15 cm, yellowish but covered with brown blackish indumentum, margins disintegrating and fibrous; petiole 30 – 150 cm long, 3.5 – 3.8 × 1.5 – 2 cm in cross section, slightly channelled, margins sharp, abaxial surface covered in caducous white to greyish tomentum; rachis 2 – 3.50 m long, 1.2 – 2 × 2.2 – 2.6 cm in cross section in mid-leaf, keeled, pale green, with irregular grey to brown tomentum, becoming glabrescent; leaflets stiff, regularly arranged, arranged in one plane, dark green, 46 – 55 on each side of the rachis, the proximal leaflets 52 – 123 × 0.8 – 2 cm, the median leaflets 116 – 124 × 4.8 – 6 cm, the distal leaflets 21 – 42 × 0.8 – 2.9 cm, leaflets spaced 4 – 6 cm apart, abaxial surface with scattered brown scales and ramenta
Morphology Reproductive morphology Flowers
Pistillate flowers yellow, sepals connate for c.1.6 mm, lobes c.0.8 × 0.7 mm; petals unequal, spathulate, coriaceous, 1.3 – 6.5 × 4.5 – 5.4 mm; staminodes 12, minute; gynoecium c.7.4 × 8 mm, gibbous, triloculate, stigmas recurved Staminate flowers yellow, calyx connate for c.0.4 mm, lobes 1.6 – 2 × 0.8 – 1 mm; petals free, 6.2 – 6.5 × 4.5 – 4.7 mm, with scattered minute red dots near the apex; stamens (6) 12, 2 opposite each petal, and 2 opposite each sepal, filaments 0.4 – 0.8 mm, anthers c.3.5 × 1.4 mm., pistillode minute
Morphology Reproductive morphology Fruits
Fruits blackish, subglobose, perianth persistent, stigmatic remains apical, 1.4 – 1.6 × 1.5 – 1.6 cm, epicarp c.0.8 mm thick, mesocarp 1.8 mm thick, spongy, endocarp spongy
Morphology Reproductive morphology Inflorescences
Pistillate inflorescence erect, branched to 1 order, peduncle 19 – 25 cm long, c.1.6 cm across, yellowish, covered with red brown tomentum; prophyll c.30 × 8 cm, pinkish, covered with red brown tomentum; peduncular bracts c.85 × 6 cm, ± equal in size, purplish-pink, abaxial surface densely covered in red brown tomentum in the upper part; rachis 30 – 35 × 1.5 – 1.7 cm, yellow but sparsely to densely covered with red brown tomentum, with 6 – 18 rachillae; rachillae 35 – 48 cm long, glabrescent, sinuous, pedicels 3.7 – 5.2 mm long Inflorescences interfoliar, solitary Staminate inflorescence pendulous, branched to 2 orders, peduncle 24 – 38 cm long, 0.8 – 1 cm wide, prophyll not seen, peduncular bracts several but only 2 preserved, c.77 and 82 cm long, c.9 cm wide, purplish, covered in red brown tomentum, rachis c.48 cm long; rachillae 9 – 15 cm long, c.0.5 mm wide; pedicel 0.6 – 1.2 mm
Morphology Reproductive morphology Seeds
Seeds 3; 1.3 – 1.4 × 0.7 – 0.8 mm, seedcoat black, 0.1 mm thick; endosperm homogeneous
Morphology Trunk
Trunk 3.5 – 10 m tall, 8 – 15 cm diam., internodes 4 – 11 cm, bark brown, wood soft, base of the crown bulbous, c.11 cm across
Note
Similar toRavenearobustior and R. krociana in having solitary inflorescences whether in male or female plants but differing from these in the lack of a ventricose trunk, a more delicate inflorescence, with pendulous rachillae, and having staminate flowers with usually 12 stamens rather than six. The presence of three seeds in the fruit is also rather unusual. The specific epithet honours Henk Beentje, monographer of Ravenea and co-author of Palms of Madagascar.

Native to:

Madagascar

Ravenea beentjei Rakotoarin. & J.Dransf. appears in other Kew resources:

Date Reference Identified As Barcode Type Status Has image?
Jan 1, 2010 Rakotoarinivo, M. [321], Madagascar 77767.000 No
Nov 4, 2009 Rakotoarinivo, M. [321], Madagascar 65256.000 No
Nov 4, 2009 Rakotoarinivo, M. [321], Madagascar 76572.000 No
Nov 1, 2009 Rakotoarinivo, M. [317], Madagascar 65257.000 holotype No
Nov 1, 2009 Rakotoarinivo, M. [RMJ317], Madagascar K000525800 holotype Yes
Nov 1, 2009 Rakotoarinivo, M. [317], Madagascar 65265.000 holotype No

First published in Kew Bull. 65: 298 (2010)

Accepted by

  • Govaerts, R.H.A. (2011). World checklist of selected plant families published update Facilitated by the Trustees of the Royal Botanic Gardens, Kew.

  • Herbarium Catalogue Specimens

    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • Kew Backbone Distributions

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

  • Kew Bulletin

    Kew Bulletin
    http://creativecommons.org/licenses/by-nc-sa/3.0

  • Kew Names and Taxonomic Backbone

    The International Plant Names Index and World Checklist of Selected Plant Families 2022. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0