Ravenea sambiranensis Jum. & H.Perrier, Ann. Inst. Bot.-Géol. Colon. Marseille , III, 1: 50 (1913)

Primary tabs

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Introduction

  • An elegant palm, rather like R. madagascariensis but with curved (rather than straight) leaves. The trees stay small on white sand on the East Coast and in populations on high mountains, but grow to canopy size in high forest on Nosy Be. The name sambiranensis comes from the Sambirano River in NW Madagascar, in which region the species was first found. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Madagascarpresent (World Checklist of Arecaceae)B
NW, W and E Madagascar, Manongarivo to Marojejy and down the East coast to Vangaindrano; outlier in Bemaraha area. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Discussion

  • There were several problems to be solved around this taxon. The types of R. sambiranensis and R. amara are quite distinct, but with material HB found in the Manongarivo Mountains the distinctions blurred; only the length of the leaf rachis and the number of leaflets is less in the plants from higher altitudes, but all other characters fall within the normal range of variation. Tree size may vary from 6 m (diam. 10 cm) in montane populations, to 25 m (diam. 30 cm) in moist lowland forest. Populations from riverine forest in the dry western Bongolava and the Bemaraha Tsingy, more than 700 km from the main population, show no differences from typical R. sambiranensis. Montane populations from Marojejy differ slightly in a longer petiole, a higher number of leaflets, a longer rachis of the staminate inflorescence; but not enough to warrant distinction even at varietal level. Eastern populations from coastal white sand forest (remnants), as well as from poor soils more inland, differ slightly in the more arching leaves and the slightly longer anthers; all differences are at one end of a range rather than absolute, and therefore we are treating this species as a variable one, rather than distinguishing geographically based subspecies with very minor morphological differences. Beentje et al. 4625 has a hastula-like structure on the leaf rachis. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Biology And Ecology

  • Littoral forest on white sand, dense moist forest or dry montane forests, steep slopes, hill crests or on almost level ground; in the West in remnant riverine forest; 1-2000 m. POLLINATION AND DISPERSAL. Flowers visited by bees and small flying beetles (pers. obs.); fruit eaten by Madagascar Blue Pigeon, and defecated seeds germinating well (as did seed from fallen fruit) (C. Birkinshaw, pers. comm.). (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Conservation

  • Vulnerable. Though widespread, the species occurs in fairly low numbers throughout habitats which are under threat. Littoral forests on white sand are disappearing fast. The western populations occur in high-risk areas. The sub-montane populations are depleted by cutting the trees for palm heart. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Common Name

Uses

Description

  • Slender small palm to majestic tree palm. TRUNK 2-30 m, 5-29 cm diam. (near crown 5-10 cm); basal boss 25-40 cm high, 32-50 cm across, with surface roots; internodes 2-13 (-18) cm (near crown 1-4 cm), nodal scars faint or clear, 2-4 cm; rarely with; sheath remnants present below the living crown; bark soft, pale grey or brown; outer wood with very hard black fibres; heartwood soft, white. Base of crown bulbous, 18-40 cm across. LEAVES 10-28 in the crown, porrect, arching to strongly arching; sheath 12-70 x 10-20 cm, whitish or brown-tomentose externally, in young leaves entire and fibrous, rupturing opposite the petiole when ageing and then the margins with hard fibres; petiole 13.5-76 cm, proximally 1.3-7 x 0.6-4 cm across, convex and white- or brown-grey-pubescent abaxially, slightly convex, flat or concave with sharp edges adaxially, distally 0.9-3 x 0.5-1.6 cm, glabrescent, dull green; rachis 0.6-2.5 m long, in mid-leaf 1.2-3.4 x 1-1.7 cm across, convex and white- to red- or grey-brown-tomentose to puberulous abaxially, glabrescent, adaxially in the proximal part with a channelled keel, more distally with a flattened keel 4-5.5 mm wide, more distal becoming angular and sharp; leaflets rigid, lanceolate, oblique, straight, acute, sometimes pendulous in their distal 1/3 (rarely in one plane), dark green, arcuate, the tips somewhat bent over, 35-67 on each side of the rachis, the proximal 20-78 x 0.2-3.3 cm, median 40-100 x 1.3-4 cm (interval 3.5-5 cm), distal 6-63 x 0.3-2.7 cm, the top pair sometimes connate for up to 2 cm, abaxially on the midrib (and sometimes on the veins) with rather many small ramenta in young leaves-none, or only basal ones in older leaves, main veins 2-7. STAMINATE INFLORESCENCE interfoliar, multiple in 5s-9s, the central ones maturing before the outer ones, erect; individual inflorescences 30-117 cm, branched to 1 or 2 orders; common prophyll membranous, 2.5-23 x 5-12 cm, rounded, tattering, densely tomentose abaxially, glabrous adaxially; peduncle 25-74 cm, 5-9 mm across proximally, distally 3-7 mm across, green, grey-brown tomentose to glabrescent; peduncular bracts respectively 7-35 x 3.2 cm (inserted at 0-0.4 cm from the base of the peduncle), 20-60 x 2-2.2 cm (inserted at 1-2 cm), 56-125 (inserted at c. 3 cm), 68-125 x 5.3 cm (inserted at c. 7 cm), all white- to grey-brown-tomentose abaxially, adaxially cream, smooth and glabrous; non-tubular peduncular bract 1.5-3.7 x 0.4-0.6 cm, but in Beentje 4501 a non-tubular peduncular bract inserted at 53 cm, 25 x 1.7 cm, membranous, adnate to the peduncle for 21 cm; rachis 20-54 cm, cream, densely pubescent proximally but glabrescent or with flaking patches, with 12-65 branched and 7-38 non-branched first order branches; proximal rachis bract 1.3-20 x 0.6 cm; first order branches at base 3-4 x 2 mm, with 3-6 rachillae; rachillae porrect, 3-23 cm, 1-1.5 mm across, sinuous, cream, with dense flowers above a 2 cm bare base; pedicels 0-1 mm; bracteole 0.7-1.8 x 0.5-0.8 mm, narrowly triangular, acute. STAMINATE FLOWERS custard-yellow, scarcely to sweetly scented; calyx with connate part 0.5-1.5 x 1.3-1.8 mm, free sepals 0.9-2.5 x 0.7-1.6 mm, ovate, acute; petals free, 1.8-5 (-6.1) x 2-3 mm, broadly ovate, acute, cream to bright custard yellow; anthers equal, 1-3.7 x 0.8-1.6 mm, filaments equal, 0.3-1.5 mm; ovary rudiment 0.4-2 x 0.3-1 mm. PISTILLATE INFLORESCENCE interfoliar, solitary, erect, 70-175 x c. 30 cm, branched to 1 order, with green axes turning orange in fruit; peduncle 29-93 cm, proximally 1.2-5 x 0.6-3 cm across, distally 0.9-2.3 x 0.5-1.5 cm, white- to brown-pubescent, glabrescent; prophyll 5-22 x 9 cm, rounded, tattering, white-pubescent; peduncular bracts 7-34 cm (inserted at 1-4 cm from the base of the peduncle), 23-90 x 4.5 cm (inserted at 2-10 cm), 53-153 cm (inserted at 7-18 cm), 55-155 cm (inserted at 12-43 cm), glabrous and chestnut-brown adaxially, silvery-white pubescent abaxially; non-tubular peduncular bract inserted at 10 cm below rachis, 6-28 x 0.6-0.7 cm; rachis bracts 10-16 x 1.5-2 mm; rachis 14-60 cm, with 28-77 porrect rachillae; rachillae green to pale yellow, 5-50 cm, 1.5-2.5 mm across, with bulbous base 3.5-13 x 3-4 mm and 2 cm bare part, the distal part sinuous; bracteole 1.5-2.8 x 0.6-2 mm, narrowly triangular, acuminate; pedicels 0.3-6 x 1.3 mm (maximum dimensions in fruit only) long. PISTILLATE FLOWERS quite dense, very fragrant, sticky; calyx connate for 0.6-2 mm, 1.3-2.5 mm across, the lobes 0.6-2.6 x 1-2.4 mm, ovate to triangular and acute to acuminate; petals 2.2-5 (-10, Du Puy 807) 1.5-2.3 mm long, (broadly) ovate and acuminate, pale or bright yellow; staminodes c. 1.3 x 0.3 mm; ovary 2.2-3.2 mm high, 1.3-1.8 mm across. FRUIT orange to coral-red, ovoid to oblong, rounded at the apex, 10-12 x 9-10 mm, one-seeded, with lateral stigmatic remains; in Birkinshaw 136 sometimes 2- or 3-lobed (but all fruits in this collection are without seed - though they are orange in colour); fruit often with a high percentage of abortive seed. SEED brown, 7-8 x 5-7.5 mm. EOPHYLL bifid. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A

Materials Examined

  • : Nosy Be: Lokobe forest, near Ampasindava, Oct. 1963 (fr.), Moore & Abdallah 9024 (BH, TAN); idem, July 1992 (fr.), Birkinshaw 136 (K); idem, July 1992 (pist.), Beentje & Andriampaniry 4699 (K, MO, P, TAN). Ambanja: 2-4 km SW of Ambalafary, Jan. 1992 (fr.), Beentje 4558 (K, TAN); idem, (old stam.), Beentje 4560 (K, MO, P, TAN); idem, Feb. 1992 (fr.), Beentje 4582 (BH, K, MO, P, TAN); "Sambirano forests", without precise locality, 500 m alt., Oct. 1919 (y.fr.), Perrier 12041 (Holotype P); Manongarivo, Bekolosi, Feb. 1992 (old stam.), Beentje et al. 4570 (BH, K, MO, P, TAN); idem, Feb. 1992 (old fr.), Beentje et al. 4572 (BH, K, MO, P, TAN); idem, Antsatrotro, Sept. 1991 (yfr.), Malcomber & Razafimandimbison 883 (K, MO, P, TAN); idem, April 1992 (stam.), Malcomber et al. 1401 (K, MO, TAN); Tsaratanana massif, c. 2000 m, April 1924 (stam., pist.), Perrier 16070 (type of R. amara, holotype P). Analalava: 18 km NNE of Maromandia, July 1992 (stam.buds), Beentje & Andriampaniry 4705 (BH, K, MO, P, TAN). Andapa: Marojejy, Nov. 1989 (stam.), Dransfield et al. JD6757 (K, TAN); idem, Nov. 1989 (pist.), Dransfield et al. JD6758 (K, TAN); Mt. Beondraka, Oct. 1989 (stam.), Miller & Randrianasolo 4391 (K, MO, TAN). Miandrivazo: Ambohitsaratelo-Bebao, Jan. 1985 (fr.), Dorr & Barnett 3619 (K, P); idem, Nov. 1986 (pist.), Dransfield et al. JD6448 (K, P, TAN) and (stam.) Dransfield et al. JD6445 (K, P, TAN); idem, June 1974 (stam.), Morat 4591 (K, P, TAN); Manambolo R. in Bemaraha massif, 28 March 1990 (yfr.), B. Du Puy et al. MB 807 (K, MO, P, TAN). Maroantsetra: Maroantsetra, Oct. 1963 (stam.), Moore 9010 (BH, TAN); idem, Oct. 1963 (pist.), Moore 9019 (BH, TAN); 15 km S of Maroantsetra, Oct. 1986 (pist.), Dransfield et al. JD6409 (K, P, TAN); Manambia, Oct. 1986 (stam.), Dransfield et al. JD6408 (K, P, TAN). Mananara Avaratra: Antanambe, Oct. 1991 (stam.), Beentje 4456 (BH, K, MO, P, TAN); idem, April 1992 (fr.), Beentje et al. 4625 (BH, K, MO, P, TAN). Toamasina: Betampona, Dec. 1925 (y.fr.), Perrier 17473 (P); idem, Oct. 1991 (stam.), Beentje 4491 (K, MO, P, TAN); idem, Oct. 1991 (pist., old fr.), Beentje 4502 (BH, K, MO, P, TAN); Ambodiriana, Dec. 1944 (fr.), Cours 1945 (K, P, TAN); Andrambolahy Kely to Andranampony, April 1951 (y.fr.), Cours 4512 (K, P, TAN). Ampasimanolotra: Ambila, Feb. 1924 (y.fr.), Perrier 15991 (P). Vatomandry: Ilaka Atsipanana, Oct. 1991 (stam.), Beentje 4503 (BH, K, MO, P, TAN); idem, (pist.), Beentje 4504 (BH, K, MO, P, TAN). Ifanadiana: Ranomafana, Maharira, April 1993 (stam.), Malcomber et al. 2448 (K,P). Farafangana: S of Farafangana, May 1992 (old stam.), Beentje & Andriampaniry 4675 (BH, K, MO, P, TAN). Vangaindrano: near Ranomena, May 1992 (old stam.), Beentje & Andriampaniry 4674 (K).
    Sight record. Île Sainte Marie (Dransfield, 1994).
    Similar specimens. Toamasina: Betampona, Beentje 4501 (BH, K, MO, P, TAN); differs from typical sambiranensis in many sheaths remaining on trunk, full of humus and debris; sheath 28 cm; median leaflets 56-68 x 2.8-3.9 cm; staminate inflorescence multiple, non-tubular peduncular bract cylindrical, porrect from proximal first order branch, thin, green, 25 x 1.7 cm porrect part, apex fringed; 22 first order branches (branched) + 7 solitary; and Tolanaro, Ste Luce, March 1989 (part of infrutescence only), Dumetz 632 (K, MO, P, TAN). In Jumelle (1927) the following specimen is cited: dry forest in the Ankaizina, on sandstone, c. 800 m alt, (pist.), Perrier 11954. This collection is not at Paris or Antananarivo. (J. Dransfield & H. Beentje, The Palms of Madagascar. 1995)A