Satranala decussilvae Beentje & J.Dransf., Kew Bull. 50: 89 (1995)

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Content

Introduction

  • One of the most exciting discoveries made during this project. The first fan palm from the rain forests of the East Coast, looking quite like a Bismarckia, but with totally different fruit. The endocarp is flanged on the outside, with straight and sinuous wings. It is tempting to speculate on the adaptive significance of this extraordinary structure. We suggest the endocarp may be adapted to being swallowed by large birds (such as the now extinct Aepyornis) - a theory which, of course, cannot be tested. However, it is worth noting that very heavily sclerified and sculptured endocarps are found in Ptychococcus and Brassiophoenix (Uhl & Dransfield 1987) and in two species of Licuala (M. Forrero, pers. comm.) in New Guinea, where they appear to be adapted to dispersal by cassowaries, extant relatives of the extinct Madagascar elephant bird. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Madagascar present (World Checklist of Arecaceae)B
Mananara Biosphere Reserve, known from a single site. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Discussion

  • As the seed germinates the cotyledonary stalk pushes its way out of the endocarp which gapes slightly along the major crest, the endocarp thus appearing somewhat like a walnut with two valves; no other palm known to us germinates in this way. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Biology And Ecology

  • Wet forest on shallow soils overlying ultramafic rock, in steep-sided valley rich in pandans and palms, at 250 - 285 m above sea level. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Conservation

  • Endangered. Known from a single site, where we have seen 30 trunked trees, 40 young ones, and many seedlings. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Common Name

  • Satranabe (Betsimisaraka). (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Uses

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

Description

  • Solitary tree palm. TRUNK 8-15 m tall, 15-18 cm diam., hard, smooth, ± straight, obscurely ringed with scars, sometimes with aerial roots above the base of the trunk; internodes 8-10 cm, nodal scars 1.5 cm wide. LEAVES (9 in young plants) 20-24 in the crown, porrect, rather stiff, with up to 6 marcescent old leaves; sheath 46-60 cm long, 35 cm diam., at the very base 70 cm wide, split from 14-44 cm, abaxially chestnut-brown near the base, more distally pale brown with scattered scales, adaxially chestnut-brown, glabrous; petiole 1.4-1.5 m (to 2.7 m in young plants), proximally 7-10 x 5-6 cm, distally 5 x 1.5 cm, abaxially with thin white tomentum and wax, adaxially brown near the base, distally green with elongate scales, shallowly channelled, the margins proximally with spines to 3 mm, distally with minute spines; adaxial hastula forming a flange 3-8 mm high, with a central lobe to 15 mm long; blade costapalmate, 110-180 cm from hastula to apex, 240-260 cm wide, with 54-57 segments, costa to 33 cm, abaxially c. 2 cm wide at the base; segments almost flat, apically bifid for 1-10 cm, with three main veins and numerous close sinuous transverse veinlets, abaxially with conspicuous white wax, both surfaces with many large laciniate scales near the base, distally with few small brown scales, outer folds 88-102 x 1.3-3.2 cm, unsplit in the basal 8-9 (outermost) -20 cm, intermediate folds 104-130 x 4.4-5.5 cm, unsplit in basal 50-52 cm, central folds 114-181 x 4-6 cm, unsplit in basal 80-100 (-137 in young plants) cm. STAMINATE INFLORESCENCE interfoliar, arching, spreading, 230 cm long; peduncle to c. 45 cm long, 3-3.5 x 2-2.8 ; cm in section distally; prophyll and peduncular bracts not seen; rachis bracts rusty-brown tomentose, the proximal 42-50 cm long, c. 6 cm diam., the distal 31 cm long, c. 1.5 cm diam.; first order branches 13, the proximal 46-50 cm long, 3-3.5 x 0.6-0.8 cm diam., with 6-9 rachillae, the distal 40-45 cm long, 0.6-0.7 x 0.4-0.6 cm diam., with 1-3 rachillae; basal rachillae 29-31 cm long, 1.1-1.4 cm diam., distal rachillae to 22 cm long, 1.1 cm diam. PISTILLATE INFLORESCENCE similar to the staminate, rachillae 28-30 cm long, c. 1-1.2 cm diam. FRUIT globose to ovoid, to 5.6 x 5 cm, epicarp smooth, purple-black, shiny, mesocarp c. 1 cm thick, rather dry-fleshy, endocarp ± globose, 34-48 x 33-45 mm, the wall c. 1-2mm thick, outer surface with conspicuous, mostly vertical flanges, radiating from the base, one forming a crest along one entire vertical circumference, thus forming two faces, the flanges on the two faces c. 6 on each face, branching and anastomosing, tending to end blind- ly and not joined to the main crest, the flanges 3-6 mm high, the whole splitting along the main crest to allow the cotyledonary stalk to emerge; inner surface of endocarp smooth. SEED closely adherent to endocarp, to 30 x 32 mm, apparently considerably smaller in some individuals; endosperm solid, deeply ruminate; embryo apical, c. 6 x 2 mm. EOPHYLL palmate; germination remote-tubular. (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Materials Examined

  • Mananara Avaratra, Oct. 1991 (vegetative, fruit), Beentje 4474 (K, TAN); April 1992 (old staminate infl.), Beentje et al. 4628 (Holotype K; isotypes BH, MO, P, TAN, WAG); Oct. 1994 (fr.), Beentje & Dransfield 4810 (K, TAN), 4815 (K, TAN), 4807 (K, TAN). . (Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar)A

Bibliography

    A. Dransfield, J. & Beentje, H. 1995: The Palms of Madagascar
    B. World Checklist of Arecaceae