Leaves clustered near the end of the branches, 9′—10′ long, with stout petioles swollen and enlarged at base, and 5—7 leaflets, or often 3-foliolate; unfolding in March and persistent until the following spring; leaflets ovate, rounded or usually contracted toward the acute or sometimes slightly emarginate apex, rounded or sometimes cordate or cuneate at base, 3′—4′ long, 2′—3′ broad, with thickened slightly revolute margins, a prominent midrib, primary veins spreading at right angles, and numerous reticulate veinlets; petiolules stout, ½′—1′ long, that of the terminal leaflet often twice as long as the others. Flowers about ⅛′ in diameter, in clusters as long or rather longer than the leaves; petals yellow-green, marked on the inner surface by dark longitudinal lines; stamens rather shorter than the petals. Fruit ripening in November and December, pendent in long graceful clusters, orange-colored, rather lustrous, ¾′ in length; seed about ¼′ long.
A tree, frequently 35°—40° high, with a short trunk sometimes 2° in diameter, stout spreading often pendulous branches forming a low broad head, and reddish brown branchlets marked by prominent leaf-scars and numerous orange-colored lenticels. Winter-buds ⅓′—½′ in length, with acuminate scales ciliate on the margin with rufous hairs. Bark of the trunk about ⅛′ thick, light reddish brown tinged with orange, often marked by dark spots caused by the exuding of the resinous gum, and separating into large thin plate-like scales displaying the bright orange color of the inner bark. Wood heavy, hard, not strong, rich dark brown streaked with red, with thick light brown or yellow sapwood of 25—30 layers of annual growth. The resinous gum obtained from incisions made in the bark is emetic, purgative, and diuretic.
Distribution. Florida, shores of Bay Biscayne, on the Everglade Keys, and on Coot Bay in the rear of Cape Sable, Dade County, and on the southern keys; very abundant; in the Bahamas, Cuba, Jamaica, and Honduras.
4. RHUS L.
Trees or shrubs, with pithy branchlets, fleshy roots, and milky sometimes caustic or watery juice. Leaves unequally pinnate, or rarely simple. Flowers mostly diœcious, rarely polygamous, white or greenish white, in more or less compound axillary or terminal panicles, the staminate and pistillate usually produced on separate plants; calyx-lobes united at base only, generally persistent; disk surrounding the base of the free ovary, coherent with the base of the calyx; petals longer than the calyx-lobes, inserted under the margin of the disk, opposite its lobes, deciduous; stamens 5, inserted on the margin of the disk alternate with the petals; filaments longer than the anthers; ovary ovoid or subglobose, sessile; styles 3, terminal, free or slightly connate at base, rising from the centre of the ovary. Fruit usually globose, smooth or covered with hairs; outer coat thin and dry, more or less resinous; stone crustaceous or bony. Seed ovoid or reniform, commonly transverse; cotyledons foliaceous, generally transverse; radicle long, uncinate, laterally accumbent.
Rhus is widely distributed, with more than one hundred species, in the extra-tropical regions of the northern and southern hemispheres. In North America the genus is widely and generally distributed from Canada to southern Mexico and from the shores of the Atlantic to those of the Pacific Ocean, with sixteen or seventeen species within the territory of the United States. Of these, four obtain the habit of small trees. The acrid poisonous juice of Rhus vernicifera DC., of China, furnishes the black varnish used in China and Japan in the manufacture of lacquer, and other species are valued for the tannin contained in their leaves or for the wax obtained from their fruit.
The name of the genus is from Ῥοῦς, the classical name of the European Sumach.
CONSPECTUS OF NORTH AMERICAN ARBORESCENT SPECIES.
Flowers in terminal thyrsoid panicles; fruit globular, clothed with acrid hairs; leaves unequally pinnate, deciduous; Sumachs. Branches and leaf-stalks densely velvety hairy; leaflets 11—31, pale on the lower surface; fruit covered with long hairs; buds inclosed in the enlarged base of the petioles; juice milky.1. [R. typhina] (A, C). Branches and leaf-stalks pubescent; rachis winged; leaflets 9—21, green on the lower surface; fruit pilose; buds not inclosed by the petioles; juice watery.2. [R. copallina] (A, C). Flowers in axillary slender panicles; fruit glabrous, white; leaves unequally pinnate, deciduous; leaflets 7—13.3. [R. vernix] (A, C). Flowers in short compact terminal panicled racemes; fruit pubescent; leaves ovate, entire or serrate, simple or rarely trifoliolate, persistent.4. [R. integrifolia] (G).