Ravenea delicatula
Ravenea (rah-vehn-EH-ah) delicatula (deh-lih-kah-TOO-lah) | |||||||
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montane forest of Andilamena. Madagascar. Photo by Dr. Mijoro Rakotoarinivo. | |||||||
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Contents
Habitat and Distribution
Endemic to Central Madagascar, known from a single site: Madagascar, Toamasina,Andilamena, Ambatobe, Behorefo. 16°59’ S ×48°50’ E. Ravenea delicatula is an understory palm of montane forest occurring between; alt. 800–1000 m at Behorefo. This forest has a low rather open canopy of 6 or 7 m tall. Trees are small, few in number and some are deciduous; the undergrowth is scrubby and full of bamboos and pandans. The humus is fine, and in certain places mosses may form a continuous lawn on the ground.Description
Solitary or clustering, dioecious, pleonanthic palm. Stem 4–5 m tall, occasionally branching, procumbent, 1.2–1.7 cm in diam. (near crown 0.7–0.8 cm), internodes 0.4–6 cm, scars 0.2–0.4 cm, surface smooth, sheath remnants occasionally persistent. Leaves 6–9 in the crown, spiral, arching; sheath 6–15 × 1.6–4.4 cm, densely covered with red-brown to grey tomentum, marginal parts disintegrating, the tomentum persistent; petiole 4.3– 8.6 cm long, proximally 0.2 × 0.1 cm, distally 0.1 × 0.1 cm, channelled, slightly convex abaxially, sparsely tomentose, the tomentum deciduous; rachis 21.6–33 cm, in mid-leaf 0.1 × 0.1 cm, medially sharply keeled, triangular, abaxially with red brown indument but soon glabrescent; leaflets 17–25 on each side of the rachis, 3 or 4 in each group, lanceolate, held in different planes, proximal 8.7–10.8 × 0.2–0.3 cm, median 11.8–14 × 0.3–0.4 cm, distal 9.6–10.6 × 0.2– 0.4 cm, top pair with 2 or 3 main veins. Staminate inflorescence interfoliar, multiple in 3s or 4s, the central ones maturing first, individual inflorescence branching to 1 order, peduncle very slender, 4.5–11.8 cm long, with red brown tomentum; common prophyll 1.1–1.4 × 0.8–1 cm, prophyll 3.2–9.6 × 0.4–06 cm, keeled, with dense red brown tomentum; peduncular bracts 2, ± the same size, densely pubescent with red brown tomentum, 15.4–17.2 × 1.1–1.3 cm, thickness less than 1 mm, opened at 5.8–7.6 cm from the base of peduncle; rachis 2.7–4.3 cm, ± glabrous, with about 6–9 rachillae, rachis bract 0.7–0.1 cm; rachillae 4.2–6.4 cm long, slightly zigzag, flowers 0.4–0.7 cm distant, pedicel about 0.5mm. Staminate flowers, sepals connate at the base for 0.4–0.6 mm, free parts 0.6–0.8 × 0.8–1 mm, acute; petals 6.2–8 × 1.8–2.6 mm, imbricate; stamens 6, uniseriate, filament 0.8–1.2 mm (3 epipetalous, adnate for 0.6–0.8 mmm), cylindrical; anthers basifixed introrse, 2.4–3 × 0.9–1.2 mm; pistillode 0.4 × 0.6 mm. Pistillate inflorescence interfoliar, solitary, branched to 1 order, 10.2–28.8 cm long, with red brown tomentum; prophylls 2, first 2.4–2.7 × 0.3–0.4 cm, second 5.1–21.2 × 1.2–1.8 cm, densely tomentose; peduncular bracts 2, 19.2–22.3 × 1.1–1.6 cm, thickness less than 1 mm, with dense red brown tomentum; rachis 2.9–4.7 cm, ± glabrous, with about 5–9 rachillae, 0.9 × 0.1 cm; rachillae 3.9–4.8 cm long, slightly zigzag, flowers 0.4–1.1 cm distant, pedicel about 0.5mm. Pistillate flowers, sepals connate at the base for 0.8–1 mm, free parts 1.4–2 × 1.1–1.4 mm, acute; petals triangular, acute, 6.8–8.5 × 2.2–3.1 mm; staminodes 6, triangular, ca. 1.4 × 0.3 mm; ovary ovoid, 3.5–4 × 1.4–1.6 mm, stigmas 3. Fruits not seen. Madagascar, Toamasina, Andilamena, Ambatobe, Behorefo, April 2006, M. Rakotoarinivo/Palmweb. Editing by edric.
Culture
Cold Hardiness Zone: 10a
Comments and Curiosities
This is a dioecious genus.
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
- Glossary of Palm Terms
- MODERN BOTANICAL LATIN
- "Just To Be Clear"
- A Must See, Photos Too
- THE SAXOPHONE STYLE ROOT GROWTH (HEEL)
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).
Rakotoarinivo, M. & Dransfield, J. 2010. New species of Dypsis and Ravenea (Arecaceae) from Madagascar.
Many Special Thanks to Ed Vaile for his long hours of tireless editing and numerous contributions.