PALME. SILVA OF NORTH AMERICA. 79 
THRINAX. 
FLowers perfect ; calyx and corolla confluent into a short cup, 6-lobed on the 
margin; stamens usually 6; ovary 1-celled; ovule basalar, erect. Fruit drupaceous, 
globose, ivory-white; exocarp fleshy; putamen crustaceous. Spadix interfoliar, elon- 
gated, paniculate. Leaves orbicular, or truncate at the base, petiolate, their petioles 
unarmed. 
Thrinax, Swartz, Prodr.57 (1788). —Schreber, Gen. 772. — fam. ii. pt. iti. 34 (sect. Porothrinax). — Sargent, Silva 
Martius, Palm. Fam. Gen. 8.— Endlicher, Gen. 253. — NV. Am. x. 49 (sect. Porothrinax) ; Bot. Gazette, xxvii. 
Meisner, Gen. 357. — Drude, Engler & Prantl Pflanzen- 83. 
Small unarmed trees, with simple endogenous stems marked below with the ring-like scars of fallen 
leaves and clothed above with the long-persistent sheaths of the leaf-stalks, and long tough wiry roots 
covered with thick orange-brown loosely attached rind. Leaves terminal, induplicate in vernation, 
alternate, orbicular, or truncate at the base, thick and firm, usually silvery white on the lower surface, 
more or less deeply divided into narrow acute two-parted obliquely folded lobes, with thickened margins 
and midribs; rachis reduced to a narrow border, with a thin usually undulate reflexed margin ; ligule 
thick, concave, pointed, often lined while young with hoary tomentum; petioles stout, elongated, flat- 
tened, rounded above and below, their margins thin and smooth, concave toward the base, and gradually 
enlarged into vaginas composed of coarse netted fibres covered with thick hoary tomentum. Spadix 
paniculate, interfoliar, pedunculate, elongated, its primary branches short, alternate, flattened, incurved, 
furnished with numerous slender terete alternate pendant secondary flower-bearing branchlets produced 
in the axils of ovate acute scarious deciduous bracts; spathes numerous, tubular, coriaceous, two-cleft, 
and more or less tomentose toward the apex, each primary branch of the panicle with its spathe and the 
node of the rachis below it included in a separate spathe, the whole surrounded by the larger spathe of 
the node next below. Flowers solitary, minute, articulate on elongated, or short thick disk-like pedicels 
in the axils of ovate acute deciduous bracts. Perianth truncate at the base, six-lobed, the lobes obscure 
or broadly ovate and acute, persistent under the fruit. Stamens six or nine,' inserted on the base of 
the perianth ; filaments subulate, thickened and scarcely united at the base, or nearly triangular and 
united below into a cup adnate to the perianth; anthers oblong, two-celled, opening longitudinally, 
inserted on the back below the middle, introrse, becoming reflexed and extrorse at maturity. Ovary 
superior, ovoid, one-celled, gradually narrowed into a stout columnar style crowned by a broad funnel- 
formed flat or oblique stigma; ovule solitary, basalar, erect, semianatropous; micropyle lateral. Fruit 
drupaceous, globose, marked at the apex by the remnants of the style and bearing at the base the 
slightly thickened perianth of the flower ; sarcocarp thin, green, crustaceous, ultimately becoming thick- 
ened, ivory-white, juicy, bitter, easily separable from the thin putamen of two closely adherent coats, 
the outer crustaceous, pale tawny brown and slightly tuberculate, the inner membranaceous, silvery 
white, and lustrous. Seed free, erect, nearly globose, slightly flattened at the two ends, depressed at 
the base; hilum subbasilar, oblong, pale, conspicuous; raphe short, unbranched, inconspicuous; testa 
thin, pale or dark chestnut-brown, and lustrous; albumen uniform, more or less deeply penetrated by a 
broad basal cavity. Embryo lateral. 
1 In all the Florida species of Thrinax and in Thrinaz parviflora, Brit. W. Ind. 515 [1864].— Hooker f. Bot. Mag. exv. t. 7088) of 
Swartz (FV. Ind. Occ. i, 614, t. 13 [1797]), the type of the genus,the Jamaica the number is said to be nine. 
number of stamens is six, but in Thrinax excelsa, Grisebach (Fl. 
