124 Bulletin 145 



CROWBERRY FAMILY. EMPETRACEAE 



BLACK CKOWBERRY. iiivATH-BSKRY. Umpetrum IligrUiH L. 



This is a prostrate, hcath-likc, evergreen, alpine shrub with 

 black berries found in the moist, peaty soil on the summits of 

 Mount Mansfield and Camel's Hump. The evergreen leaves are 

 very small, less than one-fourth of an inch in diameter. The 

 fruit is said to be a favorite food of the mountain birds. 



SUMACH FAMILY. ANACARDIACEAE 



This is an interesting family of plants, mainly tropical. Sev- 

 eral species have a resinous juice which thickens upon exposure 

 and furnishes the finest of oriental varnishes, including those 

 most prized from Japan and China. All of these are, however, 

 related to our own poison ivy and, like that, may be poisonous 

 to the skin of certain persons. The cashew and pistachio nuts 

 and the mango fruit are also valuable products from oriental 

 members of this family. As it occurs in Vermont it is rep- 

 resented by but one genus. 



THE SUMACHS. RHUS. 



These are among our most familiar shrubs. The several 

 species may be distinguished as follows : 



1. Flowers and fruit in compact clusters at the end of branches, 

 fruit reddish and hairy, plants not poisonous to the touch, 

 (the true sumachs) 2 



1. Flowers and fruit in loose clusters in the leaf axils, fruit whitish 



and smooth, plants poisonous, (the poison sumachs) 5 



2. Leaves compounded of three leaflets Fragrant sumach. 



2. Leaves comix)unded of seven or more leaflets 3 



3. Petioles winged or margined Dwarf sumach. 



3. Petioles not winged or margined 4 



4. Branches and leaf-stalks velvety-hairy Staghorn sumach. 



4. Branches and leaf-stalks smooth Smooth sumach. 



5. Leaves compounded of three leaflets Poison ivy. 



5. Leaves compounded of 7 to 13 leaflets Poison sumach. 



