A NA CA RD 1A CEA E. 60 1 



inflorescence and fruit similar to those of the two preceding; drupe covered with 

 short reddish acid hairs. In dry soil, N. S. to Br. Col., Flu., Miss, and Ariz. This 

 species and the two preceding sometimes have the whole or a part of the flower- 

 clusters changed into small leaves. A form with laciniate leaflets occurs in south- 

 ern Penn. and Del. June -Aug. 



Rhus glabra boreillis Britton, n. var. Inflorescence, and sometimes the foliage, soft- 

 pubescent. Mich, and Minn. 



4. Rhus aromatica Ait Fragrant or Sweet-scented Sumac. (I. F. f. 

 2350.) A shrub, 9-24 dm. high, ascending or diffuse. Leaves petioled, 5-10 cm. 

 long, aromatic; leaflets ovate or rhomboid, 2-8 cm. long, 1.8-3.6 cm. wide, the 

 lateral ones sessile, the terminal short-stalked, the lateral rounded or truncate, the 

 terminal cuneate at the base; flowers yellowish green, about 2 mm. broad, in clus- 

 tered spikes appearing before the leaves; drupe globose, red. In rocky woods, 

 Ont. and Vt. to Fla., Minn., Kans. and La. March-April. 



5. Rhus trilobata Nutt Ill-scented Sumac. Skunk-bush. (I. F. f. 

 2351.) A glabrous or nearly glabrous shrub, 6 18 dm. high. Leaves petioled, 

 unpleasantly odorous, 2.5-5 cm - l° n gl leaflets sessile or nearly so, puberulent when 

 young, ovate or oval, obtuse, the terminal one cuneate at the base, all crenately 

 few-lobed or toothed or sometimes entire; flowers as in the preceding species, and 

 fruit similar. 111. to S. Dak., Tex. and Cal. March. 



6. Rhus Vernix L. Poison Sumac. Poison Elder. (I. F. f. 2352.) A 

 shrub or small tree. Leaves petioled, 1.5-4 dm. long, glabrous or somewhat 

 puberulent; leaflets thin, obovate, oval, or the lowest ovate, 5-10 cm. long, 

 2.5-3.75 cm. wide, green both sides, entire, short-acuminate, short- stalked; rachis 

 terete; flowers green, about 2 mm. broad, in loose axillary panicles 7-20 cm. long; 

 drupe globose-oblong, 4 mm. in diameter, gray. In swamps, southern Ont. to 

 R. I., Fla., Minn., Mo. and La. Very poisonous. June. 



7. Rhus radicans L. Poison Ivy. Poison Oak. Climath. (I. F. f. 

 2 353) -^ woody vine, climbing by numerous aerial rootlets, the stem sometimes 

 7-10 cm. in diameter. Leaves petioled; leaflets ovate or rhombic, 2.5-15 cm. long, 

 entire or sparingly dentate or sinuate, acute or short-acuminate, the lateral sessile 

 or short-stalked, inequilateral, the terminal ones stalked; flowers green, 3 mm. 

 broad, in loose axillary panicles 2-8 cm. long; fruit similar to that of the pre- 

 ceding. Thickets and along fences, N. S. to Fla., Minn., Neb. and Ark. Very 

 poisonous, as are the three following species. May -June. 



8. Rhus Toxicodendron L. Poison Oak. Low, erect, densely and finely 

 pubescent. Leaflets ovate, mostly obtuse, crenate or crenately lobed, often to the 

 middle, so as to resemble the leaves of an oak, the sinuses sharp; petals about 

 2 mm. long; fruit depressed-globose, 6-8 mm. in diameter. In dry soil, Va. to 

 Ga. and western N. Car. 



9. Rhus microcarpa (Michx.) Steud. Northern Poison Oak. Low and 

 slender, puberulent, seldom over 4 dm. high, erect, or the stem sometimes trailing 

 and the branches erect. Leaflets lanceolate to ovate-lanceolate, thin, acuminate, 

 the middle one cuneate at the base, sharply toothed, lobed, or entire; fruit globose, 

 small. Mich. [R. Toxicodendron microcarpa Michx.] 



10. Rhus Rydbergii Small. Rydberg's Poison Oak. A shrub, less than 

 I m. high. Leaflets broadly ovate to rhombic-ovate, rather thick, slightly pubes- 

 cent on the veins beneath, 3-10 cm. long, the margins sinuate-dentate; petals 

 ovate, about 3 mm. long; fruit 5-6 mm. in diameter. Hillsides and open woods, 

 S. Dak. to Br. Col., Kans. and Ariz. May-June. 



2. COTINUS Adans. 



Shrubs or small trees, with ovate oval or obovate entire leaves, and small 

 polygamous slender-pedicelled flowers in large terminal panicles. Calyx 5-parted, 

 the segments imbricated, obtuse. Petals longer than the calyx, imbricated. 

 Stamens 5. Ovary obovoid; styles 3, lateral; stigmas very small. Drupe obliquely 

 oblong or oval, compressed, gibbous, i-seeded. Seed nearly as in Rhus. [Greek 

 name or the oleaster, or wild olive.] Two known species, the following of south- 

 eastern N. Am., the other of Europe and Asia. 



