Ravenea nana

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Ravenea (rah-vehn-EH-ah)
nana (nah'-nah)
Nana01.jpg
Photo by Michael Gray.
Scientific Classification
Genus: Ravenea (rah-vehn-EH-ah)
Species:
nana (nah'-nah)
Synonyms
None set.
Native Continent
Africa
Africa.gif
Morphology
Habit: Solitary
Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Endemic to E Madagascar, between Marojejy and Andohahela.
Madagascar. Photo by Utopia Palms & Cycads.
Ericoid bush, or low forest on rocky sites, gneiss & quartzite; alt. (?400-) 1100-1900 m; the altitude information on the printed label of the type might be wrong; we believe this is a high-altitude species.

Description

Small palm. TRUNK 3-4 m tall. LEAF sheath 12.9-16 x 1.5 cm, with thin downward-pointing marginal fibres, densely brown-tomentose; petiole 18-67 cm, proximally 0.5-1.6 x 0.4-1 cm, distally 0.7-1.2 x 0.5-0.8 cm, densely pubescent/tomentose on both surfaces, slightly to deeply channelled adaxially, convex abaxially, with sharp edges; rachis (25-) 33-40 cm, in mid-leaf 6-7 mm wide, with dense grey-brown tomentum on both surfaces; leaflets on opposite sides of the rachis at an angle of 90° with each other, 18-29 on each side of the rachis, the proximal 12-26 x 0.1-1.3 cm (interval 0.8-2 cm), median 16-35 x 0.9-2 cm, without visible ramenta or with dense minute ramenta, acuminate, main vein 1, with scales on margins only, distal 7.5-23 x 0.3-1.5 cm. STAMINATE INFLORESCENCE branched to 1 order; peduncle 28 (or more) x 0.4 x 0.25 cm, densely brown-pubescent; prophyll unknown; peduncular bracts about 10 cm, 18-25 cm, 29-40 (or more) cm, 30-41 cm; rachis bract about 11 x 2 mm; rachis 9-13 cm, with 25-40 branches, scaly proximally, glabrous distally; rachillae 2-5 cm, 0.5 mm across, straight; pedicel 0.5-1 mm. STAMINATE FLOWERS with the calyx with very short connate part and lobes 0.8-1.1 mm long; petals 4-4.4 x 1.8 mm, connate for 0.3-0.4 mm by the filament callus of the antesepalous stamens; filaments in 2 series, the antesepalous 0.4-0.5 mm, the antepetalous adnate to the petals for 0.8-1.3 mm, free for 0.2-0.3 mm; anthers 1.5-2 x 0.3-0.4 mm; pistillode 0.6-0.9 mm. PISTILLATE INFLORESCENCE 59-92 cm, branched to 1 order; peduncle 35 (or more?) -77 cm, proximally 3-6 mm across, distally 2-3.5 mm across, with dense red-brown scales, glabrescent; prophyll 6-15 cm, tattering; peduncular bracts 10-13 cm, 19-38 cm, 57-82 cm, 44-92 cm, abaxially densely scaly, adaxially glabrous, chestnut brown; non-tubular peduncular bract 4-18 x 0.3-0.5 cm; rachis 6.3-13 cm, scaly, glabrescent; rachillae 14-27 in number, 1-7.5 cm, 1.2-2 mm across, sinuous; pedicel 0.5-1.5 mm, bracteole 1-2 mm. PISTILLATE FLOWERS with the sepals 1-1.5 mm; petals (fibres only) 2.5-?5 x 1.5-1.6 mm. FRUIT 1.3-2.1 x 1.1-1.7 cm, one-seeded, stigmatic remains lateral to subbasal. Editing by edric. (J. Dransfield and H. Beentje. 1995) Editing by edric.

Culture

Growing Climate: -Temperatures from 6.C to 35.C.

Comments and Curiosities

This is a dioecious genus.

A mystery. Until more is known about its habit and inflorescences (multiple? solitary?), we are unable to include this in the key or discuss its affinities, though it resembles R. hildebrandtii from the Comoros. It differs from this species in the much denser tomentum on the leaf-sheath, the smaller leaf rachis, and the larger fruit. It is curious that the intensive collecting on Marojejy during the late 1980s did not result in a recollecting of this species. (J. Dransfield and H. Beentje. 1995)

Conservation: Endangered. Only known from three areas, and not collected in the last thirty years. (J. Dransfield and H. Beentje. 1995)

This is a tillering palm, it exhibits saxophone style root growth (it has a heel), keep top third of heel above soil elevation!


External Links

References

Phonetic spelling of Latin names by edric.

Special thanks to Geoff Stein, (Palmbob) for his hundreds of photos.

Special thanks to Palmweb.org, Dr. John Dransfield, Dr. Bill Baker & team, for their volumes of information and photos.

Glossary of Palm Terms; Based on the glossary in Dransfield, J., N.W. Uhl, C.B. Asmussen-Lange, W.J. Baker, M.M. Harley & C.E. Lewis. 2008. Genera Palmarum - Evolution and Classification of the Palms. Royal Botanic Gardens, Kew. All images copyright of the artists and photographers (see images for credits).

Dransfield, J. & Beentje, H. 1995. The Palms of Madagascar. Royal Botanic Gardens, Kew and The International Palm Society.


Many Special Thanks to Ed Vaile for his long hours of tireless editing and numerous contributions.

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