Ravenea robustior

Ravenea (rah-vehn-EH-ah) robustior (roh-boos-TEE-or)
Mt. Warning Caldera, Nth. NSW, Australia. Photo by Pete.
Scientific Classification
Genus: Ravenea (rah-vehn-EH-ah) Species: robustior (roh-boos-TEE-or)
Synonyms
None set.
Native Continent
Africa
Morphology
Habit: Solitary Leaf type: Pinnate
Culture
Survivability index
Common names
Hovotravavy (Tsimihety); Manara, Tanave, Retanana (Betsimisaraka); Monimony, Loharanga at Analamazaotra, Anivona at Andasibe (fide Dransfield, Moore); Laafa at Ranomafana; Anivo, Lakabolavo at Amby; Bobokaomby at Manombo; Vakabe, Vakaky, Vakaboloka, ?Bokombio at Andohahela.

Habitat and Distribution

North West, East and South East Madagascar, from Manongarivo to Marojejy, and south to Andohahela.

Atsimo-Atsinana, MG-FI, Madagascar. by Dr. Franck Rakotonasolo.

Moist forest in valley bottoms, on medium or steep slopes, near water or near hill crests; in open or closed forest; often locally common; 1-1000 (-2000) m. (J. Dransfield and H. Beentje. 1995)/Palmweb.

Widespread in the forests of the central and eastern escarpment of Madagascar occurring from Taolagnaro to Daraina (eol.org)

Description

A majestic palm. TRUNK 12-30 m high, columnar or slightly ventricose, 20-60 cm. in diam. at breast height, increasing to 75 cm, decreasing to 16-40 cm near crown; base bulbous, 15-50 cm high, 47-100 cm across, with surface roots to 30 cm long, 6-12 mm across, with minute adventituous side roots; outer wood hard, heartwood white and soft; leaf scars obscure, 3-7 cm; internodes 7-25 cm (near crown 4-5 cm); bark pale brown, pale reddish or grey, closely fissured to smooth. Distal part of trunk usually with remnants of sheaths. Wood extremely hard on the outside, due to many black fibres; heartwood soft, white. LEAVES 11-25 in the crown, spiral, porrect, held in shuttlecock, straight or nearly so, often held on edge in the distal part of the leaf; leaflets stiff or curved downwards in the proximal part of the leaf; sheath grading smoothly into the petiole, ligules present or absent, about (38-) 50-112 cm, 16-45 cm wide, bulbous or not, abaxially densely white- to grey-brown tomentose, later glabrescent, adaxially pale orange, with some stiff reflexed marginal fibres 1.5-2.5 mm across; petiole 17-134 cm, proximally 8-17 x 2-4 cm, distally 3.8-8 x 1.3-4.5 cm, channelled with sharp edges or slightly convex adaxially, convex abaxially, thickly grey-brown tomentose, glabrescent; rachis 2.2-4 m, in mid-leaf 1-4.7 cm high, 1.7-3.3 cm wide, medially sharply keeled or flat (on same tree!), abaxially with grey indument but quickly glabrescent; leaflets regular, in one plane or those at opposite sides of the rachis at a slight (up to 120°) upwards angle, dark green, (40-) 50-105 on each side of the rachis, the proximal (19-) 45-120 x 1-4 cm, median 60-126 x 2.5-7.5 cm (interval 2-5 cm), distal 13-46 x 0.3-3.5 cm, top pair often connate for up to 5 cm, ramenta large, many in young leaves, a few proximal ones in older leaves, deciduous, 1-6 main veins. STAMINATE INFLORESCENCE solitary, erect, interfoliar or infrafoliar among dead leaf bases, branching to 2 (-3 in Humbert 6232) orders; peduncle 50-60 cm, proximally 2.8-3.3 x 2.5 cm, distally 2.2-2.8 x 1.3-2 cm, densely pubescent; prophyll 13-47 cm; 1st peduncular bract 18-77 R AVENEA x 8 cm (inserted at 3-11 cm from the base of the peduncle), 2nd (39-) 109-160 x 10 cm (inserted at 5 cm), 3rd 166-209 x 15.5 cm (inserted at 13 cm), 4th 175-209 cm (inserted at ?), all bracts abaxially with thick pale or red-brown tomentum; non-tubular peduncular bract about 19 x 1 cm; rachis 84-131 cm long, proximally pubescent, distally glabrous, yellowish; proximal rachis bract 4-19 x 0.8-2.4 cm; rachillae many (in the lowland population with 60-140 branched and 39 unbranched first order branches), distally densely packed, porrect, straw-yellow, straight or distally sinuous, (5-) 10-47 cm, 1.5-2 mm across; pedicels quite closely set, 0.2-3 mm long; bracteoles 0.7-1 mm long; calyx with connate part 0.8-1.8 mm long and 1.4-2.2 mm across, and free sepals 0.9-1.5 mm long and 1.2-1.8 mm wide, triangular, acute; petals ovate, acute, 1.4-5 x 1.2-2.2 mm, not connate or very briefly connate by the filaments; filaments of all 6 stamens equal, 0.5-1 mm, not or only slightly attached to the petals; anthers 1.5-2.8 x 0.7-1.3 mm; pistillode 0.6-0.8 mm. PISTILLATE INFLORESCENCE interfoliar, solitary, erect, spreading or pendulous in fruit, all axes orange in fruit, branched to 1 order (to 2 orders in Beentje 4600); peduncle 45-100 cm, proximally 3-4.5 x 2.3-2.5 cm, distally 1.2-3.5 x 0.9-2.8 cm, pale green, proximally densely grey-white pubescent, distally glabrescent; prophyll 16-22 x 9-10 cm; peduncular bracts 21-40 x 9 cm (inserted at 5-20 cm from the base of the peduncle), 50-70 x 5-6 cm (inserted at 10-24 cm), 90-120 x 5-6 cm (inserted at about 27 cm), 70-150 x 5-6 cm (inserted at 30-70 cm), all grey-brown tomentose abaxially; rachis 55-80 cm, with 45-100 spreading or reflexed rachillae; proximal rachis bract about 32 x 2.2 cm; rachillae pale waxy green to orange (in fruit), 9-81 cm, 3-4 mm across, distally sinuous, proximally with bulbous bases, 1.2-2.4 x 1.2-1.8 cm, glabrous; pedicels 1-28 mm; bracteole 0.7-1.2 x 0.5-0.6 mm, connate for 0.8-6 mm; calyx connate for 0.8-2.2 mm, 2-3.5 mm across, free lobes 1.5-2.2 x 1.4-2.5 mm; petals (1.6) 4-4.2 x 1.8-2.4 mm; staminodes 0.8 mm; ovary about 3.5 mm. FRUIT orange, obovoid to ovoid-globose, 10-18 x 8-15 mm; usually one-seeded, then stigmatic remains subbasal; occasionally 2-3-seeded, then stigmatic remains terminal. SEED red-brown, hard, 9-16 x 6-13 mm; seedcoat brown, 0.2 mm thick. EOPHYLL bifid. (J. Dransfield and H. Beentje. 1995)/Palmweb. Editing by edric.

Culture

"Ravenea krociana and robustior are very very similar and sometimes wrongly tagged in Botanic gardens etc, the stand out difference is that Robustiors leaflets are "thinner" and having grown/growing both Krokiana is a faster grower than Robustior." (Pete)