82 



SELECTED WESTERN FLORA 



XLVI. ANACARDIACE^. 



Trees or shrubs with an acrid, milky, or somewhat resinous juice, 

 alternate exstipulate leaves, and regular, 5-merous, generally polyg- 

 amous flowers; ovary 1-celled and 1-ovuled; styles or stigmas 3. 

 Some species exceedingly poisonous. 



1. RHUS. Sumach. 



Calyx 5-parted; petals 5; stamens 5, inserted on a disk at the 

 bottom of the calyx; flowers greenish or yellowish; fruit. drupe-like. 



1. R. toxicodendron, L. Poison Ivy; 



Poison Oak. 

 Low, erect from a creeping root- 

 stock, usually glabrate; leaves 3- 

 foliate, ovate to rhombic, rather 

 thick, often irregularly few-toothed ; 

 berries whitish, persisting through 

 the winter. Poisonous to the touch 

 to many people. Common in thick- 

 ets, Man.-Alta. 



2. R. canadensis. Marsh. 



A shrub 3-7 ft. high, scented; 

 leaves thin, 3-foliate, soft-pubescent 

 when young; leaflets ovate or obo- 

 vate, the terminal sometimes 3-cleft, 

 and all coarsely toothed or incised, 

 1-3 in. long; flowers yellow; drupes 

 rather large. (Var. trilobata, (Nutt.) 

 Leaflets small, usually about i in. long, lobed or incised, mostly 

 summit. S-W. Sask. and Alta. 



Fig. 58. — Rhus toxicodendron. 



Gray.) 

 at the 



XLVII. CELASTRACE^ 



Shrubs with alternate simple leaves and regular flowers; sepals 

 and petals 4 or 5, inferior; stamens as many as the petals, alternate 

 with them, periginous; seeds with an appendage (aril) growing up 

 from the point of attachment, and sometimes covering the seed. 



1. CELASTRUS. Bitter-sweet. 



Flowers polygamous, with a tendency to be dioecious, in raceme- 

 like clusters terminating the branches; petals and stamens 5, 



