50 ANACARDIACEAE 



1. Floerkea proserpinacoides Willd. False Mermaid. Fig. 3081. 



Floerkea proserpinacoides Willd. Neue Schrift. Ges. Nat. 3: 449. 1801. 

 Floerkea occidenlalis Rydb. Mem. N.Y. Bot. Card. 1:268. 1900. 



Stems slender, weak, 1-4 dm. long. Leaves pinnate, slender-petioled, 2-7 cm. long; leaflets 

 usually 5, distant, lanceolate to linear-oblong; sepals lanceolate, 3-5 mm. long; petals half the 

 length of the sepals, oblong, white ; fruiting carpels nearly globular, 3 mm. in diameter, tubercu- 

 late above. 



Wet places, Transition Zone; Kittitas County, Washington, to the central Sierra Nevada, California, east 

 to Quebec, Missouri, and New Jersey. Type locality: Pennsylvania. April-June. 



Family 84. ANACARDIACEAE. 



Sumac Family. 



Trees or shrubs, with a resinous or milky and usually acrid juice. Leaves alter- 

 nate or rarely opposite, simple or compound, persistent or deciduous. Flowers com- 

 monly regular, perfect or polygamo-dioecious. Calyx 3-7-lobed. Petals of the same 

 number as the calyx-lobes, imbricated in the bud, rarely wanting. Stamens as many 

 or twice as many as the petals, rarely fewer or more, inserted at the base of the 

 annular disk. Ovary in the pistillate flowers 1 -celled or sometimes 4-5-celled; styles 

 1-3 ; ovules 1 in each cell. Fruit usually a small drupe. Seeds with a bony or crus- 

 taceous testa ; endosperm scanty or none. 



A family of about 50 genera and 400 species, most abundant in the warm temperate and tropical regions. 



1. RHUS L. Sp. PI. 265. 1753. 



Shrubs or small trees, with alternate, simple or compound leaves. Flowers polygamous, 

 in axillary or terminal panicles. Calyx-lobes 4-6, usually 5, persistent. Petals imbricated 

 in the bud, spreading in anthesis. Disk annular. Stamens 5. Ovary 1-celled, 1-ovuled; 

 styles 3, terminal. Drupe small, subglobose or compressed, pubescent or glabrous, the 

 exocarp persistent or deciduous. Seed solitary, inverted on a stalk that rises from the 

 base of the ovary. [Ancient classical name.] 



About 120 species, inhabiting the temperate and tropical regions, most abundant in South Africa. Type 

 species, Rhus Coriaria L. 



Leaves compound, deciduous. 



Leaves odd-pinnate; leaflets 11-31. 1. R. glabra. 



Leaves 3-foliolate. 



Ovary and fruit glabrous; exocarp exfoliating; stone ribbed; plants poisonous. 



Panicles lax and open; leaflets rounded or obtuse at apex. 2. R. diversiloba. 



Panicles dense; leaflets acuminate at apex. 3. R- radicans. 



Ovary and fruit pubescent; exocarp persistent; stone smooth; plants not poisonous. 4. R. trilobata. 

 Leaves simple, persistent. 



Ovary and fruit pubescent and viscid; stone smooth, compressed. 



Leaves oval, very obtuse at both ends; exocarp of fruit acid to taste. 5. R. integrifolia. 



Leaves ovate, acute at apex; exocarp of fruit sweetish to taste. 6. R. ovata. 



Ovary and fruit glabrous; stone rugose along one edge, not compressed. 7. R. laurina. 



1 . Rhus glabra L. Smooth or Scarlet Sumac. Fig. 3082. 



Rhus glabra L. Sp. PI. 265. 1753. 



Shrub or small tree, 1-6 m. high, glabrous and somewhat glaucous. Leaflets 11-31, lanceolate 

 or oblong-lanceolate, 2.5-10 cm. long, acuminate, sharply serrulate; inflorescence a large dense 

 terminal panicle; flowers greenish, about 3 mm. broad; drupe compressed, about 4 mm. in 

 diameter, covered with short reddish hairs. 



A variable and widely distributed species, ranging from Nova Scotia to Florida and westward to British 

 Columbia and the Pacific States. In the Pacific States two forms are found which may deserve subspecific rank: 

 Rhus glabra var. occidenlalis Torr. (Bot. Wilkes Exp. 257. 1862-74.) occurs in the Upper Sonoran Zone of 

 eastern Washington and northeastern Oregon. Another form of the Arizona type, Rhus calophylla Greene (Rep. 

 Nov. Spec. 5: 45. 1908.) occurs in Chino Canyon near Palm Springs, southern California. Type locality: east- 

 ern North America. May-July. 



2. Rhus diversiloba Torr. & Gray. Pacific Poison Oak. Fig. 3083. 



Rhus diversiloba Torr. & Gray, Fl. N. Amer. 1: 218. 1838. 

 Toxicodendron divcrsilobum Greene, Leaflets Bot. Obs. 1: 119. 1905. 



An erect shrub. 1-3 m. high or in forests becoming a vine and ascending trees by means of 

 aerial roots to a maximum height of 40 m. or more. Leaves 3-foliolate, deciduous; leaflets ovate, 

 obovate or elliptical, obtuse or rounded at the apex, variously lobed or toothed, or rarely entire, 

 the lateral ones usually sessile; panicles axillary, loosely flowered and drooping or spreading; 



