Marojejya Humbert
  • Mém. Inst. Sci. Madagascar, Sér. B, Biol. Vég. 6: 92 (1955) 


Notes: Distribution: Madagascar

General Description

Stout, solitary, unarmed, monoecious, pleonanthic palms. Stem erect, obscurely ringed with leaf scars, internodes short, sometimes with short root spines. Leaves numerous, massive, pinnate or ± entire, the crown often filled with fibres; sheath with or without rounded auricles; petiole absent or thick and wide at the base, gradually tapering to the rachis, adaxially channelled, abaxially rounded, densely covered with caducous, dense brown scales; rachis adaxially deeply channelled, abaxially rounded basally, becoming laterally channelled distally, densely scaly at the base, blade undivided for ca. 1/4 to the entire length, where not entire, distally irregularly divided into, 1–several-nerved, obtuse leaflets with decurrent bases, the blade eventually splitting irregularly, abaxially with scattered irregular bands of caducous, chocolate-brown scales, numerous fine, longitudinal veins between the major ribs, transverse veinlets not evident. Inflorescences unisexual (but see below), hidden among the leaf bases beneath debris, branching to 1 order, staminate and pistillate inflorescences basically similar but staminate with more numerous slender and longer branches; peduncle large, slightly flattened, short, densely covered in dark brown scales; prophyll tubular, 2-keeled, strongly flattened, splitting longitudinally, thinly coriaceous, bearing numerous caducous, dark brown scales; basal peduncular bract similar to the prophyll but smaller, subsequent peduncular bracts numerous, crowded, spirally arranged, incomplete, acute to acuminate, stiff, ± erect, gradually diminishing in size distally; rachis shorter than the peduncle, bearing spirally arranged rachillae, each subtended by a conspicuous, acute or acuminate bract; staminate rachillae ± equal in length, stout, catkin-like, somewhat flexuous, densely covered in brown tomentum; rachilla bracts conspicuous, paired, narrow, triangular, subtending densely crowded, paired staminate flowers except near the base and at the tip where solitary staminate flowers present, flowers abortive at the very base, rarely a few pistillate flowers present at the base (as a monstrosity), distal bracts forming pits; floral bracteoles 2, well-developed, acute, ciliate margined. Staminate flowers rather small, somewhat asymmetrical due to close packing; sepals 3, free, unequal, narrow, ovate, keeled, chaffy, ciliate margined, tending to be widely separated; petals 3, ± boat-shaped, valvate, coriaceous, connate basally for 1/3 their length and adnate to the receptacle; stamens 6, filaments basally connate, the distinct portions flattened, tapering, elongate, inflexed at the tip, anthers medifixed, ± versatile, latrorse; pistillode small, 3 lobed. Pollen ellipsoidal asymmetric, occasionally lozenge-shaped, pyriform or oblate triangular; aperture a distal sulcus, infrequently a trichotomosulcus; ectexine tectate, perforate-rugulate, aperture margin similar, or slightly finer; infratectum columellate; longest axis ranging from 34–37 µm [2/2]. Pistillate rachillae shorter, thicker, and fewer than the staminate, densely brown tomentose, bearing crowded, spirally arranged, triangular bracts forming the lower lips of shallow pits, each pit bearing 3 membranous bracteoles, 2 very small abortive staminate flowers and a large solitary pistillate flower. Pistillate flowers much larger than the staminate, obpyriform, somewhat asymmetrical; sepals 3, distinct, somewhat chaffy, ovate with triangular tips, ± striate; petals 3, distinct, similar to the sepals but larger and with short, triangular, valvate tips; staminodes 6, narrow, triangular; gynoecium gibbous, unilocular, uniovulate, gradually tapering to 3, large, triangular, recurved stigmas, ovule large, pendulous, campylotropous. Fruit asymmetrically globular, perianth persistent, stigmatic remains forming a large lateral beak; epicarp smooth, mesocarp thin, granular, endocarp composed of several layers of broad, soft anastomosing fibres closely adhering to the seed. Seed irregularly rounded, flattened, or ± kidney-shaped, smooth or grooved and ridged, subapically attached, endosperm homogeneous; embryo basal, opposite the fruit attachment. Germination adjacent-ligular; eophyll bifid, with or without a petiole. Cytology: 2n = 32.

Diagnostic Description

Robust squat litter-trapping palms from rain forest in Madagascar, remarkable for their condensed unisexual inflorescences, found among the leaf sheaths, but with both sexes found on the same tree.

Morphology

Root (Seubert 1998a, 1998b), ovule with distinct tannin and fibrous and vascular bundle layer around locule, ovule unusually large (Uhl unpublished).

Biology

Occurring on hill slopes and in swamps in tropical rain forest from sea leavel to about 900 m altitude.

Distribution

Two species endemic to the rain forests of Madagascar.

Uses

Much prized ornamentals.

Common Names

Ravin-be (Malagasy).

Distribution Map

 
  • Native distribution
Found in
  • Africa Western Indian Ocean Madagascar

  Bibliography

  • 1 J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008
  • 2 Govaerts, R. & Dransfield, J. (2005). World Checklist of Palms: 1-223. The Board of Trustees of the Royal Botanic Gardens, Kew.

 Information From

Palmweb - Palms of the World Online
http://www.palmweb.org
Palmweb 2011. Palmweb: Palms of the World Online. Published on the internet http://www.palmweb.org. Accessed on 21/04/2013
  • A Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
  • B http://creativecommons.org/publicdomain/zero/1.0
eMonocot
http://e-monocot.org
eMonocot. (2010, 1st November). Retrieved Wednesday, 8th February, 2012, from http://e-monocot.org.
  • C Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
World Checklist of Selected Plant Families
http://apps.kew.org/wcsp/
WCSP 2014. 'World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://apps.kew.org/wcsp/ Retrieved 2011 onwards
  • D See http://kew.org/about-kew/website-information/legal-notices/index.htm You may use data on these Terms and Conditions and on further condition that: The data is not used for commercial purposes; You may copy and retain data solely for scholarly, educational or research purposes; You may not publish our data, except for small extracts provided for illustrative purposes and duly acknowledged; You acknowledge the source of the data by the words "With the permission of the Trustees of the Royal Botanic Gardens, Kew" in a position which is reasonably prominent in view of your use of the data; Any other use of data or any other content from this website may only be made with our prior written agreement.