Medemia Württemb. ex H.Wendl.
  • Bot. Zeitung (Berlin) 39: 89 (1881) 


Notes: Distribution: S. Egypt to N. Sudan

General Description

Robust, solitary, unarmed, pleonanthic, dioecious, tree palm. Stem erect, ringed with close leaf scars. Leaves induplicately costapalmate, marcescent, or falling under their own weight; sheath soon becoming open, densely tomentose, later with a conspicuous triangular cleft below the petiole, margins fibrous; petiole well developed, flattened adaxially, rounded abaxially, the margins armed with widely spaced coarse, forward-pointing spines, mostly in the mid-section; hastulae absent; costa short, more conspicuous abaxially than adaxially; blade divided ± regularly along adaxial folds to ca. 2/3 its length into single-fold segments, these further divided for a very short distance along abaxial folds, interfold filaments persistent at the adaxial sinuses, surfaces ± glaucous, with scattered dot-like scales, particularly along the ribs on the abaxial surface, longitudinal veins crowded, transverse veinlets obscure. Inflorescences interfoliar, becoming pendulous; prophyll and peduncular bracts, if any, not seen; rachis bracts tubular, with scattered caducous scales, and a long triangular limb; first-order branches ± pendulous, devoid of bracts except at the tip, margins sharp, the surfaces bearing scattered caducous scales, staminate inflorescence with first-order branches bearing at their tips 1–7 digitately displayed rachillae, in the pistillate bearing a single rachilla; rachillae catkin-like, bearing a tight spiral of rounded, densely hairy, imbricate bracts, connate laterally and to the axis to produce pits, filled with a dense pile of hairs. Staminate flowers borne in threes, each bearing a spathulate membranous bracteole included within the pit, the flowers exserted and exposed one by one from the pit; calyx stalk-like at the base with 3 narrow, spathulate, membranous, striate lobes with irregular margins; corolla with a conspicuous stalk-like base almost as long as the calyx lobes, bearing at its tip 3 oblong, membranous, striate, ±circular lobes; stamens 6, borne at the base of the corolla lobes, filaments elongate, tapering, anthers medifixed, apparently versatile, latrorse; pistillode 3-lobed, small. Pollen ellipsoidal, slightly asymmetric; aperture a distal sulcus; ectexine tectate, coarsely perforate-rugulate, aperture margin slightly finer; infratectum columellate; longest axis 36–49 µm [1/1]. Pistillate flowers solitary, borne on a short, densely hairy pedicel, lengthening after fertilisation; sepals 3, distinct, imbricate, obtuse, broad, membranous, glabrous, striate; petals 3, similar to the sepals; ?staminodes; gynoecium globose, with 3 eccentric, short, recurved stigmas, ovule probably orthotropous. Fruit ovoid, borne on the elongated pedicel, usually developed from only 1 carpel, rarely from 2 and then bilobed, with basal stigmatic remains, perianth whorls persistent; epicarp smooth, shiny, marked with scattered lenticels, mesocarp moderate, apparently ± dry at maturity, with ± radiating short fibres embedded in soft parenchyma, endocarp rather thin, crustaceous. Seed basally attached, ± broad, ellipsoidal, endosperm with a central hollow, conspicuously ruminate, the ruminations radial; embryo apical. Germination remote-tubular; eophyll entire, lanceolate. Cytology not studied.

Diagnostic Description

Moderate solitary dioecious fan palm of desert oases in Egypt and Sudan, distinctive in the absence of a hastula and the rounded fruit with smooth endocarp and ruminate endosperm.

Morphology

Leaf (Tomlinson 1961).

Biology

Two species have been described, Medemia argun and M. abiadensis, the latter differing in its smaller fruit. Boulos (1968) records variation in fruit size in Egypt and most authors have, since Beccari, accepted one species only, M. argun. It occurs in desert oases. Gibbons and Spanner (1996) suggest that the habitat of M. abiadensis appears to differ from that of M. argun, and that the recognition of a single species may require reassessment.

Distribution

Egyptian Nubia and northeastern Sudan.

Uses

Medemia may have had the same range of uses as Hyphaene (Johnson 1985); over-exploitation may partly account for its rarity.

Common Names

Medemia or Argun palm.

Distribution Map

 
  • Native distribution
Found in
  • Africa Northeast Tropical Africa Sudan
  • Northern Africa Egypt

  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.