250 



ANACARDIACEA:. 



Edwards' Canon near Crockett; Lake Co. The shrub of the Sierra 

 Foothills is doubtless the same species. Apr. -May. Fruit maturing 

 in June, occasionally triquetrous and 3-seeded. 



51. ANACARDIACE/E. Sumach Family. 



Trees or shrubs with resinous or milky acrid juice. Leaves alter- 

 nate, usually compound, without stipules. Flowers regular, perfect 

 or polygamous. Calyx and corolla 5-merous, the stamens as many or 

 twice as many as the petals. Pistil 1, ovary free from the calyx, 

 1-celled, 1-ovuled, styles or stigmas 3. A glandular ring or cup-like 

 disk lines the base of the calyx. An order containing the Poison 

 Sumachs and also many tropical trees of economic importance. 



1. RHUS L. Sumach. 

 Ours deciduous shrubs with 3 (sometimes 5)-foliolate leaves and 

 very small flowers. Sepals and petals usually 5. Stamens inserted 

 under the edge of a perigynous disk which is quite free from the 

 ovary. Styles 3. Fruit a small compressed drupe with thin flesh 

 and bony stone. Seed erect; endosperm none. (Ancient name.) 



Flowers greenish, in small panicles; drupe white 1. R. diversiloba. 



Flowers yellow, in dense spikes; drupe red 2. It. trilobata. 



1. R. diversiloba T. & G. Poison Oak. Erect and 4 to 5 ft. 

 high, or ascending the trunks of trees by the means of aerial rootlets to 

 the height of 15 to 20 ft.; leaflets orbicular to ovate or oblong-ovate, 

 undulate, entire or variously lobed, segmented, or toothed; panicles 

 axillary, appearing with the leaves, short-peduncled, more or less 

 pendulous; flowers 1$ lines long; sepals often unequal and sometimes 

 4; anthers yellow; fruit 3 lines broad, the stone striate. 



Everywhere common throughout California. Flowering in Apr. 

 and May. Few persons, like the author, enjoy complete immunity 

 from the poisonous effects of this plant. Leaflets in size, outline and 

 segmentation singularly variable, even on the same shrub. Fruit- 

 clusters persisting on the nnked branches well into midwinter, the 

 thin skin of the drupes deciduous and exposing the dry whitish flesh 

 which is marked with several longitudinal depressed blackish nerves. 



2. R. trilobata Nutt. var. quinata Jepson. Squaw Bush. Some- 

 what diffusely branching, 2 to 5 ft. high; leaves 3-foliale; terminal 

 leaflets 3-cleft, -parted or -divided, the divisions as also the lateral 

 leaflets crenate or crenately lobed towards the apex; spikes about £ 

 in. long, often clustered; flowers pale yellow, appearing before the 

 leaves, 1 line long; sepals scarious; petals elliptic; disk yellow, 

 5-lobed, the lobes opposite the leaves and somewhat emarginate; 

 fruit scarlet, viscidly pilose, the stone smooth. 



Canon bottoms or narrow mountain valleys, particularly along the 

 banks of arroyos, either solitary or forming circular thickets 3 or 4 

 ft. hisrh and several yards across. Throughout California, but not 

 near the coast within our limits: middle and inner North Coast 



