600 FLORA. 



ments separate ; anthers commonly versatile. Ovary in the staminate 

 flowers i-celled. Ovary in the pistillate flowers i- or sometimes 4-5- 

 celled ; styles 1-3; ovules i in each cavity. Fruit generally a small drupe. 

 Seed-coat bony or crustaceous; endosperm little or none; cotyledons 

 fleshy. About 50 genera and 400 species, most abundant in warm or 

 tropical regions, a few extending into the temperate zones. 

 Styles terminal ; leaves compound in our species; fruit nearly symmetrical, i. Rhus. 

 Styles lateral ; leaves simple ; fruit gibbous. 2. Cotinus, 



i. RHUS L. 



Leaves alternate, simple, 3-foliolate, or odd-pinnate, estipulate. Flowers 

 small, polygamous, in panicles. Calyx 4-6-cleft or parted (commonly 5-cleft), per- 

 sistent. Petals equal, imbricated, spreading. Disk annular. Stamens (in our 

 species) 5. Pistil i, sessile; ovary i-ovuled; styles 3, terminal. Drupe small, i- 

 seeded, mostly subglobose, pubescent or glabrous. Seed inverted on a stalk that 

 rises from the base of the ovary; cotyledons nearly flat. [Ancient Greek and Latin 

 name; Celtic, red.] About 120 species, natives of warm and temperate regions, 

 most abundant in South Africa. Besides the following, about 8 others occur in the 

 southern and western parts of the U. S. 



Fruit pubescent ; stone smooth. 



Leaflets 9-31; flowers appearing after the leaves. 



Rachis of the leaf wing-margined. i. R. copallina. 



Rachis of the leaf nearly terete. 



Foliage and twigs velvety-pubescent. 2. R. hirta. 



Foliage and twigs mostly glabrous and glaucous. 3. R. glabra. 

 Leaflets 3 ; flowers appearing before the leaves. 



Leaflets 2-8 cm. long, pubescent, crenate-dentate. 4. R. aromatica. 



Leaflets 1.25-2.5 cm. long, glabrate, with few rounded teeth. 



5. R. trilobata. 

 Fruit glabrous ; stone striate. 



Leaflets 7-13, glabrous. 6. R. Vernix. 



Leaflets 3, more or less pubescent beneath. 



Vine climbing by aerial rootlets, or trailing, rarely suberect. 



7. R. radicans. 

 Low shrubs, mostly without aerial rootlets. 



Leaflets very pubescent, crenately lobed; southern. 



8. R. Toxicodendron. 

 Leaflets sparingly pubescent, entire, sinuate, or acutely lobed. 



Leaflets entire or acutely lobed; fruit 3-4 mm. in diameter; northern. 



9. R. microcarpa. 

 Leaflets sinuate; fruit 5-6 mm. in diameter; western. 



10. R. Rydbergii. 



1. Rhus copalUna L. DWARF, BLACK OR MOUNTAIN SUMAC. UPLAND 

 SUMAC. (I. F. f. 2347.) A shrub, or sometimes a small tree. Leaves pinnate, 

 1.5-3 dm. l n g> the petiole and rachis more or less pubescent; leaflets 9-21, ovate- 

 lanceolate or oblong-lanceolate, inequilateral, entire, or few-toothed toward the 

 apex, dark green and glabrous above, paler and often pubescent beneath ; flowers 

 green, 3 mm. broad, in dense terminal panicles; pedicels and calyx finely pubes- 

 cent; diupe compressed, 4 mm. in diameter, crimson, covered with short acid hairs. 

 In dry soil, Me. and southern Ont. to Fla., Minn., Neb. and Tex. June- Aug. 



2. Rhus hirta (L.) Sudw. STAGHORN SUMAC. (I. F. f. 2348.) A small 

 tree, or often shrubby. Leaves pinnate, 2-4 dm. long; leaflets 11-31, lanceolate 

 or oblong -lanceolate, 7.5-12 cm. long, acuminate, rounded at the base, sharply 

 serrate, dark green and nearly glabrous above, pale and more or less pubescent 

 beneath; panicles terminal, dense; flowers green, 3 mm. broad; drupe globose, 

 3-4 mm. in diameter. In dry or rocky soil, N. S. to Ga., Ont., S. Dak., Mo. and 

 Miss. A form with laciniate leaflets has been found in New Hampshire. June. 



3. Rhus glabra L. SMOOTH UPLAND OR SCARLET SUMAC. (I. F. f. 2349.) 

 A shrub or rarely a small tree, 6-60 dm. high, similar to the preceding species, 

 but glabrous and somewhat glaucous. Leaflets 11-31, lanceolate or oblong- lanceo- 

 late. 5-10 cm. long, acuminate, rounded and often oblique at the base, dark green 

 *bove, whitish beneath, sharply serrate; pedicels sometimes slightly pubescent; 



