4. TREMA Lour.
Unarmed trees and shrubs with watery juices and terete branchlets. Leaves alternate, often two-ranked, serrate, penniveined, three-nerved from the base, short-petiolate, persistent; stipules lateral, free, usually small, caducous. Flowers apetalous, small, monœcious, diœcious or rarely perfect, in axillary cymes; calyx five or rarely four-parted, the lobes induplicate, valvate or slightly imbricated in the bud, or in perfect flowers more or less concave and induplicate; stamens five or rarely four, opposite the calyx-lobes and inserted on their base, occasionally present in the pistillate flower; filaments short, erect; anthers oblong, attached on the back near the base, introrse, two-celled, the cells opening longitudinally; ovary sessile, rudimentary or wanting in the staminate flower; style central, slightly or entirely divided into two linear fleshy stigmatic branches; ovule solitary, pendulous from the apex of the cell, anatropous; micropyle superior. Fruit drupaceous, short-oblong to subglobose, crowned by the persistent style; exocarp more or less fleshy; endocarp hard; seed filling the cavity of the nutlet; testa membranaceous, albumen fleshy, often scanty; embryo curved or slightly involute; cotyledons narrow; radicle incurved, ascending.
Trema, with about twenty species, is widely distributed in tropical and subtropical regions of the two hemispheres. Two species reach the coast region and the keys of southern Florida. Of these Trema mollis Lour. is a small tree, and Trema Lamarckiana Bl., which in Florida has been noticed only on Key Largo, where it grows as a small shrub, is widely distributed over the Bahamas and many of the West Indian islands.
1. [Trema mollis] Lour.
Trema floridana Britt.
Leaves 2-ranked, ovate, abruptly acuminate at apex, rounded, cordate and often oblique at base, finely serrate with incurved or rounded apiculate teeth, dark green and scabrate above, covered with pale tomentum below, 3′—4′ long, 1′—2½′ wide; petioles stout, tomentose, about ⅖′ in length; stipules narrow, acuminate, covered with long white hairs, about one third as long as the petioles. Flowers in early spring, subtended by minute scarious deciduous bracts on short slender pedicels in bisexual many-flowered pedunculate villose cymes about as long as the petioles; calyx 5-lobed, the lobes oblong, acute and incurved at apex, villose on the outer surface; staminate with glabrous filaments and slightly exserted yellow anthers; pistillate with a style divided to the base. Fruit short-oblong, pale yellowish brown, ⅙′—⅕′ in diameter.
A fast-growing short-lived tree, in Florida occasionally 25°—30° high, with a tall trunk 1½′—2½′ in diameter, small crowded branches ascending at narrow angles, and stout hoary-tomentose red-brown 2-ranked branchlets. Bark thin, chocolate-brown, roughened by numerous small wart-like excrescences, and separating into small appressed papery scales.
Distribution. Rich hummocks; near the shores of Bay Biscayne, in the Everglades, and on the southern keys, Florida; common; often springing up where the ground has been burned over, or otherwise cleared of its forests; on many of the West Indian islands and in Mexico.