PALME SILVA OF NORTH AMERICA. 53 
THRINAX MICROCARPA. 
Silver-Top Palmetto. Brittle Thatch. 
PEpIcELs short, disk-like ; filaments triangular. Fruit orange-brown, the pericarp 
crustaceous; seed dark chestnut-brown and lustrous. 
Thrinax microcarpa, Sargent, Garden and Forest, ix. 162 Roemer & Schultes) (1883). — Sargent, Forest Trees N. 
(1896). Am. 10th Census U. S. ix. 218. 
Thrinax argentea, Chapman, Fl. ed. 2, Suppl. 651 (not 
A tree, in Florida rarely more than thirty feet in height, with a trunk eight or ten inches in 
diameter, covered with thin smooth pale blue-green rind. The leaves are orbicular, coriaceous, pale 
green above, silvery white below, more or less thickly coated while young with hoary tomentum at the 
base, especially on the lower surface, from two to three feet across, and split to below the middle or 
near the base of the leaf almost to the rachis into divisions which are an inch wide at the middle of the 
leaf, and rather less than a quarter of an inch wide at its base, and are thickened and revolute on 
the margins, with midribs thickened and prominent on the upper side and slender veins; the rachises 
are short, slightly convex, and gradually narrowed and rounded at the apex; the ligulas are orbicular, 
thick, concave, an inch wide, and lned with a thick coat of white tomentum ; the petioles are thin and 
flexuose, an inch wide at the apex, and gradually widened below into elongated light brown sheaths of 
slender fibres. The flower-clusters, which appear in April, are elongated, with short compressed erect 
secondary branches, slightly spreading below, gracefully incurved above the middle, and furnished with 
numerous slender pendulous flower-bearmg branchlets subtended by small lanceolate acute scarious 
bracts; the spathes are elongated, acute, deeply parted at the apex, coriaceous, and coated above the 
middle with thick hoary tomentum. The flowers are solitary, articulate on short thick disk-like 
pedicels, and about an eighth of an inch long; the cupular perianth is truncate at the base and 
six-lobed, with broadly ovate acute lobes half as long as the ovary. The stamens are six in number, 
with thin nearly triangular exserted filaments slightly united at the base and slender at the apex, and 
oblong anthers, which are attached on the back near the bottom and versatile, becoming reversed and 
extrorse at maturity. The ovary is ovoid, deep orange-colored, one-celled, and narrowed above into a 
short thick style dilated into a large funnel-formed stigma. The fruit, which ripens late in the autumn 
or during the winter, is globose, an eighth of an inch in diameter, dull yellow-brown, surmounted by 
the remnants of the style, surrounded at the base by the slightly enlarged obscurely six-lobed thickened 
perianth of the flower, and raised on a short thick stalk; the outer coat is thin, brittle, and closely 
invests the much thinner membranaceous inner coat, which is ight brown and lustrous on the inner 
surface. The seed is subglobose, with uniform albumen, bright dark chestnut-brown, and depressed 
and marked at the base by the conspicuous oblong pale hilum. 
The wood of Thrinax microcarpa is light and soft, and contains numerous small fibro-vascular 
bundles, the interior of the trunk being spongy and much lighter than the hard exterior rim, which is 
from half an inch to an inch in thickness, and, when absolutely dry, has a specific gravity of 0.7172, a 
cubic foot weighing 44.70 pounds. The stems are used for wharf-piles, and the thick coriaceous 
brittle leaves are employed as thatch, and manufactured into coarse ropes. 
Thrinax microcarpa grows in dry coral soil, and inhabits No-name Key, Bahia Honda Key, and 
the shores of Sugar Loaf Sound in southern Florida. It was discovered by Mr. A. H. Curtiss* in 1879. 
1 See ui. 50. 
