SPONDIACEAE 727 



b. Leaflets with coarsely toothed or lobed blades. 



Drupes 4-5 mm. thick. 4. R. rhomboidea. 



Drupes 6-7 mm. thick. 5. R. Toxicodendron. 



B. Leaf-blades pinnately 7-11-foliolate : tall shrub or small tree. 6. E. Vernix. 



1. Rhus radicans L. A deep green vine, with a poisonous sap. Stems climbing by 

 rootlets : leaflets 3, the blades membranous, ovate or ovate-lanceolate, 4-20 cm. long, entire, 

 coarsely toothed or rarely lobed, often sparingly pubescent, especially beneath, acuminate 

 at the apex, rounded or acute at the base : panicles rather loosely-flowered, axillary : flow- 

 ers greenish, 4-5 mm. long : sepals ovate, obtuse, 1 mm. long : petals 5, oblong or oblong- 

 ovate, obtuse, nerved, recurved : stamens 5, erect : filaments linear-s.ubulate : drupes sub- 

 globosej 5-6 mm. in diameter. 



In thickets, woods and fence rows, Nova Scotia to Minnesota, Florida, Arkansas and Nebraska. 

 Spring and summer. POISON IVY. POISON OAK. 



2. Rhus Floridana Mearns. Similar to R. radwans in habit, but smaller and more 

 slender. Leaflets 3, the blades relatively thin, lanceolate to narrowly ovate, entire or 

 rarely undulate-toothed, glabrous or minutely pubescent : flowers smaller than those of R. 

 radicans : drupes 3-4 mm. in diameter. 



In hammocks, peninsular Florida. Spring and summer. 



3. Rhus Blodg6ttii Kearney. Shrubby, several dm. tall, the twigs pubescent, 

 reddish brown. Leaflets 3, the blades leathery, ovate or oblong-ovate, 3-5 cm. long, short- 

 acuminate, entire, rounded or acutish at the base, the upper surface dark green and lus- 

 trous, the lower surface dull, pubescent in the axils and at the base of the midrib : drupes 

 subglobose, 2.5-3 mm. in diameter, yellowish white, shining : stone minutely roughened, 

 10-12-ribbed, ash-colored. 



In sand, Key West, Florida. Spring and summer. 



4. Rhus rhomboidea Small. A spreading shrub, about 1 m. tall. Leaflets 3, 

 the blades ovate or sometimes obovate in outline, 2-6 cm. long, 3-5-lobed, pubescent on 

 both sides or glabrate above, dark green, the lobes entire or coarsely toothed : panicles 

 many flowered but not dense, pubescent : pedicels slender, 4-5 mm. long, the bracts 1-2 

 mm. long : flowers whitish, 5 mm. broad : sepals 5, ovate, 1 mm. long, rounded at the 

 apex : petals oblong-ovate, conspicuously nerved, 2 mm. long, curled back and revolute, 

 obtuse : stamens erect ; filaments broadly subulate, flattened, about as long as the anthers : 

 drupes subglobose, 4-5 mm. in diameter. 



In rocky hillsides, the Indian Territory and Texas. Spring. 



5. Rhus Toxicod6ndron L. A low shrub 2-10 dm. tall, with tomentose foliage 

 and inflorescence, spreading by underground stems. Leaflets 3, the blades leathery, ovate 

 in outline or rarely obovate, coarsely crenate or lobed, obtuse, more densely tomentose 

 beneath than above, the lateral ones sessile : panicles axillary, densely flowered : flowers 

 greenish white, 3-4 mm. broad : sepals oblong, ascending, obtuse : petals 5, oblong to 

 oblong-lanceolate, obtuse, about 2.5 mm. long, curled back : stamens 5, erect ; filaments 

 linear-subulate, about as long as the anthers : drupes depressed-globose, greenish yellow, 

 6-7 mm. in diameter. 



In pine lands and the foothills, North Carolina to Florida and Texas. Spring. POISON OAK. 



6. Rhus V6rnlx L. A shrub or small tree, sometimes 8"m. tall, with a very poison- 

 ous sap and a pale bark. Leaflets 7-13, the blades oblong, elliptic or oval, the terminal one 

 sometimes obovate, 4-15 cm. long, acuminate at both ends, undulate, often inequilateral, 

 more or less pubescent beneath, becoming glabrous above : panicles axillary, on elongated 

 peduncles, rather loosely many-flowered : flowers greenish : sepals ovate, about 1 mm. long 

 apiculate ; petals linear-oblong, 2 mm. long, obtuse, curved, erect, the tips slightly turned 

 back : stamens longer than the petals in the staminate flowers, much shorter in the pis- 

 tillate flowers : drupes subglobose, flattened, about 5 mm. broad, in drooping panicles, 

 white. [R. venenata DC.] 



In swamps, Ontario to Minnesota, south to Florida and Louisiana. Spring. POISON SUMAC. 

 POISON OAK. POISON ELDER. POISON DOGWOOD. THUNDER-WOOD. 



4. SCHMALTZIA Desv. 



Shrubs or trees, usually with pubescent foliage and rarely if at all poisonous. Leaves 

 alternate, 3-foliolate or pinnately several-foliolate : leaflets with generally toothed, or some- 

 what lobed blades. Flowers in terminal panicles, sometimes densely crowded, polygamous 

 or dioecious. Sepals commonly 5. Petals commonly 5, imbricated. Ovary 1-celled. 

 Ovule pendulous. Drupe red, clothed with acid-secreting hairs, the sarcocarp thin and 

 never wax -secreting, its slender strands tending to persist with the outer coat than with the 

 even and smooth stone. SUMAC. 



