Thrinax

Swartz

Prodr. 4, 57. 1788.

Common names: Thatch palm
Etymology: Greek thrinax, trident or winnowing fork presumably in reference to shape of leaf
Synonyms: Hemithrinax Hooker f.
Treatment appears in FNA Volume 22. Treatment on page 98.

Plants small to moderate. Stem solitary, erect, ± smooth. Leaves: sheath producing soft fibers; petiole split at base, unarmed; abaxial hastula a small crescent-shaped ridge or absent; adaxial hastula irregularly semicircular to nearly cylindric; blade palmate; plication induplicate; segments lanceolate, basally connate; cross-veins conspicuous [obscure]. Inflorescences interfoliar, emerging through split leaf-bases, arching beyond leaves, with 2 orders of pendent branches; prophyll short; peduncular bracts many, tubular. Flowers bisexual, borne singly along rachillae, short to long-pedicellate; perianth 1-seriate, shallowly cupulate, lobes 5–7, apiculate; stamens 6–12, erect [inflexed in bud]; filaments acute; anthers dorsifixed; pistils 1, 1-carpellate, glabrous; stigma funnelform. Fruits globose; stigmatic scar apical; exocarp white, smooth, slightly warty or rugose when dry; mesocarp mealy; endocarp membranaceous. Seeds oblate-globose; hilum deeply intruded into seed, forming cylindric depression or perforation; endosperm homogeneous, bony; embryo nearly apical; eophyll undivided, lanceolate. nx = 18.

Distribution

Regions along shores, North America (Fla.), Mexico, West Indies (Bahamas), and Central America

Discussion

Thrinax lacks a showy perianth and is wind pollinated, although many insects visit the inflorescence (D. W. Roubik, pers. comm.) and may transferport some pollen once the lateral lobes of the stigma have opened to expose the stigmatic surfaces. Fruits are taken by birds (R. W. Read 1975), including the red-bellied woodpecker (Melanerpes carolinus), lizards (J. B. Iverson 1979), and gray squirrels, which probably disperse the seeds. Key deer consume T. morrisii fruits, but they are probably not seed dispersers (W. D. Klimstra and A. L. Dooley 1990; W. D. Klimstra, pers. comm.).

Species 7 (2 in the flora).

Key

1 Leaf sheath liguliform opposite petiole; hastula silky-pubescent adaxially; leaf blades glaucous; segment apices stiff; pedicel inconspicuous in fruit. Thrinax morrisii
1 Leaf sheath with V-shaped cleft opposite petiole; hastula glabrous adaxially; leaf blades green; segment apices lax; pedicel conspicuous in fruit (usually exceeding 1 mm) Thrinax radiata
... more about "Thrinax"
irregularly semicircular +  and nearly cylindric +
dorsifixed +
Scott Zona +
Swartz +
Thatch palm +
Regions along shores +, North America (Fla.) +, Mexico +, West Indies (Bahamas) +  and and Central America +
membranaceous +
lanceolate +
Greek thrinax, trident or winnowing fork +  and presumably in reference to shape of leaf +
rugose +  and warty +
adnate +, connate +  and distinct +
long-pedicellate +
adnate +, connate +  and distinct +
berrylike +  and drupaceous +
apical +  and basal +
globose +
branched +  and spicate +
2-pinnate +  and pinnate +
? (?) +  and ? (?) +
fibrous +, dry +  and fleshy +
connate +  and distinct +
bearing prickles or marginal teeth +  and unarmed +
ridged +, channeled +  and terete +
list +  and count +
v--shaped +  and tent--shaped +
germination +
read1975a +
crescent--shaped +
adventitious +
adhering to endocarp +  and free +
oblate-globose +
bearing prickles +  and unarmed +
connate +  and distinct +
6 (?) +  and 12 (?) +
subterranean +
enlarged;massive;slender +
connate +  and distinct +
Hemithrinax +
Thrinax +
Arecaceae (tribe Corypheae) subtribe Thrinacinae +
unbranched +  and branched +
unisexual +  and bisexual +
small +  and moderate +