104 American Midland Naturalist Monograph No. 4 



merous short flowering branches appearing the second year; leaves usually 

 composed of 3 leaflets (rarely 5), or the upper sometimes merely lobed, the 

 leaf-stalks prickly; leaflets oval, tapering to a point at the tip, the margins 

 toothed, roughish above, somewhat hairy below; % to 2 inches long; flowers 

 white; fruit black when ripe, cylindrical, 1/3 to % inch long. 



Trailing blackberry is one of the first species to invade burned areas. 

 However, since strong sunlight is required for best growth and fruit produc- 

 tion, the plants are gradually shaded out as the taller conifers and other 

 plants develop. Like most blackberries, this plant is particularly valuable in 

 erosion control work. The long trailing stems soon form a maze of tangled 

 briers and serve efl^ectively to bind the soil. 



The leaves are browsed by deer and elk. Birds and small mammals eat 

 the berries, which are usually produced in abundance. They are sweet and 

 delicious and are often gathered by local residents for pies or preserving. 

 Several varieties of cultivated blackberry have been developed from this species. 



Occurrence. — OLYMPIC, common at the lower elevations up to about 1,500 feet: 

 Mount Angeles; Elwha River; Skokomish River; Crystal Creek. MOUNT RAINIER, 

 common, up to 2,000 feet: lower southern slope of Shrmer Peak in burned area. 

 CRATER LAKE, rare in southwest corner of park: Redblanket Canyon. 



6. Snow Dewberry (Rubus nivalis Dougl.). — Very similar to trailing 



blackberry, but with mostly simple leaves, smooth and somewhat shiny, less 



prickly stems, and red berries. 



Occurrence. — OLYMPIC: Lake Crescent; Mount Angeles. MOUNT RAINIER: Nisqually 

 Valley. 



7. CuTLEAF Blackberry (Rubus laciniatus Willd.). — Shrubs with 

 climbing stems 4 to 15 feet long, armed with stout backwardly-curved thorns; 

 leaves divided into 3 to 5 leaflets, these again deeply divided into rather fine 

 pointed sections, somewhat hairy below; flowers white or pinkish, borne in 

 elongate clusters at the ends of the stems; fruit a blackberry. 



This blackberry is a garden plant escaped from cultivation. Although not 

 important in the parks, it is occasionally found growing wild, and where it 

 has become established it may form dense thickets, particularly near streams. 



Oc^irrenc. — OLYIVP'C, rare, at low elevations. MOUNT RAINIER: rocky soil near 

 Longmire. YOSEMITE: Hazel Green meadows, 6,000 feet. GLACIER: Lake McDonald 

 Hotel. 



8. Yankee Blackberry (Rubus frondosus Bigel.). — Shrubs with erect 

 spreading or arching stems, armed with stiff straight or slightly curved prickles; 

 leaflets usually 5 (or 3 on flowering branches), sharply double-toothed, nearly 

 smooth above, velvety below; flowering branches hairy; flowers white, about 1 

 inch across; fruits black when ripe, smooth, nearly globose, the drupelets 

 rather few. 



Occurrence. — ISLE ROYALE, rare: ridge between Lake Benson and Forbes Lake. 



The Himalayan Blackberry (Rubus procerus Muell.) is found at In- 

 dian Gardens in the Grand Canyon where it was cultivated before the area 

 became a national park. 



