Socratea H.Karst.
  • Linnaea 28: 263 (1857) 

Notes: Distribution: C. & S. Trop. America

General Description

Solitary or very rarely clustered, moderate, pleonanthic, monoecioustree palms. Stems erect, conspicuously ringed with leaf scars, bearingan open cone of stout, usually densely prickly, stilt roots. Leaves ratherfew, pinnate, neatly abcising; sheaths tubular forming a well-definedcrownshaft; petiole short, adaxially channelled or flattened, abaxiallyrounded, bearing a variety of indumentum types; rachis adaxiallyangled, abaxially rounded; leaflets regularly arranged, asymmetricallydeltoid to elliptic, proximal margin entire for much of its length, distalmargin entire ca. 1/3 its length, otherwise praemorse, main ribsnumerous, radiating from the base, leaflet remaining entire or splittinglongitudinally between the ribs into narrow segments displayed indifferent planes giving the leaf a plumose appearance. Inflorescences solitary, infrafoliar, somewhat dorsiventrally compressed and erect inbud, branching to 1 order, branches pendulous when exposed,protogynous; peduncle well developed, elliptic in cross-section,winged at base; prophyll inserted near the base, short, tubular, 2-keeled, apically open, thinly coriaceous; peduncular bracts ca. 5,tubular, tips pointed, central ones larger than proximal or distal, ±flattened, eventually deciduous after anthesis; rachis ± flattened,shorter or longer than the peduncle, bearing spirally arranged,pendulous rachillae, each subtended by a minute collar-like bract;rachillae rather robust, often somewhat flattened, elongate, bearingspirally arranged, crowded triads; rachilla bracts and bracteoles scarcelyevident; staminate and pistillate flowers maturing at the same time.Staminate flowers open in bud, sepals 3, triangular, united basally in alow, complete or partially interrupted ring; petals 3, distinct, fleshy, markedly asymmetrical, lightly imbricate basally, much longer than the sepals; stamens 17–145, filaments very short, awl-shaped above expanded bases, anthers erect, basifixed, linear, acute or apiculate, latrorse; pistillode much shorter than the stamens, conical, briefly trifid. Pollen ellipsoidal, ± bi-symmetric; aperture a distal sulcus; ectexine intectate, upper surface of foot layer covered by fine, dense gemmae or clavae, loosely supporting short, wide-spaced, broad-based spines; longest axis 43–50 µm [2/5]. Pistillate flowers symmetrical, much smaller than the staminate, ± 3-angled; sepals 3, rounded, strongly imbricate, dorsally thickened; petals 3, distinct, strongly imbricate, ± rounded with a minute, triangular valvate apex; staminodes 6, minute, tooth-like; gynoecium obovoid, tricarpellate, triovulate, stigmas 3, apical, fleshy, reflexed, ovules basally attached, orthotropous, one usually larger than the others. Fruit separated at maturity, ellipsoidal to subglobose with eccentrically apical stigmatic remains; epicarp minutely roughened when dry, at maturity splitting into ± distinct valves at apex, exposing the rather dry white mesocarp with included reddish sclerosomes and slender fibres, endocarp thin. Seed ± ovoid, basally attached, hilum circular, raphe branches conspicuous, numerous, sparsely anastomosing, endosperm homogeneous; embryo eccentrically apical. Germination adjacent-ligular; eophyll bifid with praemorse tips. Cytology: 2n = 36.

Diagnostic Description

Moderate solitary (very rarely clustered) pinnate-leaved tree palms ofhumid rain forest in Central and South America, the stems with an opencone of stilt roots; leaflets are rhomboid praemorse, sometimeslongitudinally divided to give the whole leaf an ostrich-featherappearance; fruit has apical stigmatic remains and embryo.


Leaf (Tomlinson 1961, Roth 1990), root (Tomlinson 1961, Seubert 1998a, 1998b, Avalos 2004), gynoecium (Uhl and Moore 1971), floral development (Uhl and Moore 1980), seed (Roth 1990).


Occurring in lowland and montane tropical rain forest; pollination, where known, is by beetles (Henderson 1985).


Five accepted species: one, Socratea exorrhiza, is very widely distributed from Nicaragua and Costa Rica southward to Colombia, Ecuador, Peru, Venezuela, Guyana, Surinam, Brazil and Bolivia; the other four are much more restricted in the Andes or adjacent lowland areas.


The outer layers of the trunk are extremely hard and durable and are used, split, in the construction of houses and corrals. Wallace (1853) records the use of the spiny roots as cassava graters. Older palms may be cut to make bows (Balick 1985).

Common Names

Stilt palms.

Distribution Map

  • Native distribution
Found in
  • Southern America Brazil Brazil North
  • Brazil Northeast
  • Central America Costa Rica
  • Nicaragua
  • Panamá
  • Northern South America French Guiana
  • Guyana
  • Suriname
  • Venezuela
  • Western South America Bolivia
  • Colombia
  • Ecuador
  • Peru


  • 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
Palmweb 2011. Palmweb: Palms of the World Online. Published on the internet Accessed on 21/04/2013
  • A Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License
  • B John Dransfield, Royal Botanic Gardens, Kew
  • C
WCS higher taxonomy
  • D All Rights Reserved
World Checklist of Selected Plant Families
WCSP 2014. 'World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; Retrieved 2011 onwards
  • E See 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.