Thrinax L.f. ex Sw.
  • Prodr. Veg. Ind. Occ.: 57 (1788) 


Notes: Distribution: S. Florida, SE. Mexico to Honduras, Caribbean

General Description

Small to moderate, solitary, unarmed, pleonanthic, hermaphroditic palms. Stem erect, columnar, smooth or fibrous, tan or grey, obscurely ringed with leaf scars, usually with a basal mass of fibrous roots. Leaves induplicate, palmate, often irregular; sheath becoming split both opposite the petiole and abaxially to emit the inflorescence, disintegrating into irregular fibres, covered in thick, deciduous tomentum, margins fibrous; petiole long, slender, rounded to shallowly ridged both adaxially and abaxially, margins rather sharp; adaxial hastula prominent, long pointed, frequently inrolled, short and blunt at high elevations, abaxial hastula less conspicuous, rounded or triangular, lacking or very small at high elevations; blade fan-shaped, often irregularly folded segments united basally 1/2 their length or less, lanceolate, pointed and usually bifid apically, glabrous adaxially, abaxially variously scaly, sometimes white, midrib and marginal ribs conspicuous, transverse veinlets evident. Inflorescences interfoliar, slender, erect to arching, branched to 2 orders, primary branches pendulous; peduncle moderate, rather slender, round in cross-section; prophyll short, tubular, 2-keeled, pointed, opening distally, tomentose; peduncular bracts several (ca. 4), like the prophyll but lacking keels, overlapping and very closely sheathing the peduncle; rachis longer than the peduncle, slender, tapering, bearing spirally arranged, long, tubular, pointed distally and obliquely open primary bracts subtending first-order branches; first-order branches each with a short basal bare portion, bearing a 2-keeled, bifid prophyll and spirally arranged, narrow, triangular bracts subtending rachillae; rachillae slender, rather short, stiff, bearing spirally arranged, small triangular bracts subtending solitary flowers, bracteoles apparently lacking. Flowers borne on conspicuous stalks; perianth a single cupule with 6 lobes or teeth; stamens mostly 6–12 (5–15), filaments very slender, sometimes partly united basally, anthers elongate, dorsifixed near the base, emarginate apically, latrorse; gynoecium consisting of 1 carpel, unilocular, uniovulate, ovule basally attached, erect, campylotropous but tilted so that the micropyle faces the upper dorsal wall of the locule, and with a basal aril. Pollen ellipsoidal, less frequently oblate triangular, with slight to obvious asymmetry; aperture a distal sulcus, less frequently a trichotomosulcus; ectexine tectate, perforate, or perforate-rugulate, aperture margin similar or slightly finer; infratectum columellate; longest axis 24–46 µm [2/3]. Fruit very small, white at maturity, stigmatic remains apical, perianth often persistent; epicarp smooth when fresh, sometimes drying pebbled, mesocarp thin, mealy, endocarp very thin, papery. Seed depressed-globose, smooth, hilum round, impressed, forming a basal intrusion, raphe branches deeply impressed forming peripheral ruminations, otherwise endosperm homogeneous; embryo lateral to subapical. Germination remote-tubular; eophyll narrow, lanceolate. Cytology: 2n = 36.

Diagnostic Description

Small to moderate, solitary hermaphroditic fan palms found in Caribbean islands and neighbouring coastal mainland; leaf sheaths fibrous, petiole bases deeply split at base; flowers and fruit stalked; fruit very small, white, the seed smooth.

Morphology

Leaf (Read 1975), roots (Seubert 1997), floral (Morrow 1965, Uhl and Moore 1971), fruit (Murray 1973, Reddy and Kulkarni 1982, Essig 1999); correlations of floral anatomy and wind pollination suggested by Uhl and Moore (1977a).

Biology

Each of the three species in Jamaica is confined to one habitat: T. parviflora to dry evergreen woodland or thicket, T. excelsa to lower montane rain forest, and T. radiata, which thrives under exposure to salt-laden winds, to littoral woodland or thicket.

Distribution

Three species; of which two, Thrinax parviflora and T. excelsa, are endemic to Jamaica. Thrinax radiata also occurs in Jamaica but is widely distributed in littoral habitats of Atlantic Honduras, Belize, Mexico and the northern Caribbean.

Uses

Leaves are used for thatch, fibre for basketry, and other purposes. The heart of some species is eaten.

Common Names

Thatch palms, Key palms.

Distribution Map

 
  • Native distribution
Found in
  • Northern America Mexico Mexico Southeast
  • Southeastern U.S.A. Florida
  • Southern America Caribbean Bahamas
  • Cayman Is.
  • Cuba
  • Dominican Republic
  • Haiti
  • Jamaica
  • Central America Belize
  • Honduras
  • Nicaragua

  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.