Prota 2: Vegetables/Légumes
Ann. Inst. Bot.-Géol. Colon. Marseille sér. 3, 1(1): 49, t. 27 (1913).
Origin and geographic distribution
Ravenea robustior is endemic to Madagascar.
The young terminal bud (palm heart) of Ravenea robustior is eaten as a vegetable, but some consider it too bitter. The palms are said to be large enough to feed a whole village. It is reported that the ‘pith’, the central soft part of the trunk, can be eaten as well. Young leaves are used for making brooms, and fully developed leaves are used for thatching. The outer wood is used for making floorboards, tables, house walls; it is said to be termite resistant. In former days salt was extracted from the ash of the trunk pith. Ravenea robustior is also a specialty ornamental.
There is no specific information on the composition of the palm heart of Ravenea robustior, but probably it is comparable to that of palm heart in general which contains per 100 g raw edible portion: water 69.5 g, energy 481 kJ (115 kcal), protein 2.7 g, fat 0.2 g, carbohydrate 25.6 g, fibre 1.5 g, Ca 18 mg, Mg 10 mg, P 140 mg, Fe 1.7 mg, vitamin A 68 IU, thiamin 0.05 mg, riboflavin 0.18 mg, niacin 0.9 mg, folate 24 mg, ascorbic acid 8 mg (USDA, 2002).
The wood is extremely hard on the outside, due to many black fibres. The heartwood is soft and white.
Large palm with trunk (6–)12–30 m tall, 20–60 cm in diameter at breast height, base bulbous, 50–100 cm across. Leaves 11–25 in crown, pinnately compound; sheath grading smoothly into the petiole; petiole up to 135 cm long, channelled with sharp edges, thickly grey -brown tomentose; rachis up to 4 m long; leaflets (40–)50–105 on each side of the rachis, stiff, dark green, median leaflets 60–125 cm × 5.5–7.5 cm at intervals of 2–5 cm, top pair often connate for up to 5 cm. Inflorescence unisexual, solitary; male inflorescence branching to 2 orders, peduncle 50–60 cm long, bracts 6, rachis 85–130 cm long, yellowish, with 60–140 branches up to 50 cm long, straw-yellow; female inflorescence spreading or pendulous in fruit, branched to 1 order, peduncle 45–100 cm long, bracts 6, rachis 55–80 cm long, with 45–100 branches up to 80 cm long, waxy green to orange when in fruit. Fruit an orange, obovoid to ovoid-globose drupe 1–2 cm × 1–1.5 cm, 1(–3)-seeded. Seed 9–16 mm × 6–13 mm, red-brown, hard.
In Madagascar the palm heart of three other Ravenea species is eaten. Ravenea dransfieldii Beentje has a bitter palm heart, but it is eaten although some believe it to be poisonous; the leaf fibres are used in hat making. Ravenea sambiranensis Jum. & H.Perrier has a slightly bitter palm heart, which is eaten cooked with manioc; the fruits are also consumed and the outer wood is suitable for making planks for floorboards. The palm heart of Ravenea albicans (Jum.) Beentje is also eaten.
Ravenea robustior grows in moist forest in valley bottoms, on medium or steep slopes, near water or near hill crests, from sea-level up to 1000(–2000) m altitude. It is locally common.
Ravenea robustior is reported as being cultivated in Madagascar but no further details are known. Seeds, collected from the wild, are offered on the international market for ornamental purposes. The seeds do not seem to be recalcitrant. There are about 1700 seeds per kg and germination takes 1–3 months.
Genetic resources and breeding
The continued cutting for palm heart and construction wood might endanger Ravenea robustior in the near future, although some protected populations exist in nature reserves. Ravenea albicans is ranked ‘endangered’ with only two known locations; Ravenea dransfieldii and Ravenea sambiranensis are both ranked ‘vulnerable’.
Ravenea robustior is an important source of food (with high nutritional value) and other useful plant parts for the local population. In view of the increasing scarcity of this palm and the long life cycle, it is important to extend planting activities. Seed should be collected from various provenances for safekeeping of the genetic diversity.
• Beentje, H.J., 1994. A monograph of Ravenea (Palmae: Ceroxyloideae). Kew Bulletin 49(4): 623–671.
• Beentje, H.J., 1995. Ravenea in Madagascar. Principes 38(4): 195–203.
• Dransfield, J. & Beentje, H.J., 1995. The palms of Madagascar. Royal Botanic Gardens, Kew and The International Palm Society, United Kingdom. 475 pp.
• Jumelle, H., 1927. Ravenea et Louvelia, palmiers de Madagascar. Annales de l’Institut Botanico-Géologique Colonial de Marseille 5(1): 21–51.
• Jumelle, H., 1945. Palmiers (Palmae). Flore de Madagascar et des Comores (plantes vasculaires), famille 30. Imprimerie Officielle, Tananarive, Madagascar. 180 pp.
• Ferguson, I.K., Dransfield, J. & Flawn, I., 1988. A review of the pollen morphology and systematics of the genera Ravenea and Louvelia (Ceroxyleae: Ceroxyloideae: Palmae). Journal of Palynology 23–24: 65–72.
• USDA, 2002. USDA nutrient database for standard reference, release 15. [Internet] U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Beltsville Md, United States. http://www.nal.usda.gov/fnic/foodcomp. Accessed June 2003.
Correct citation of this article:
van der Burg, W.J., 2004. Ravenea robustior Jum. & H.Perrier In: Grubben, G.J.H. & Denton, O.A. (Editors). PROTA 2: Vegetables/Légumes. [CD-Rom]. PROTA, Wageningen, Netherlands.