204 ROSACEAE. 



Rubus macropetalus Dougl. (R. helleri Rydb.) Dewberry. Stems slightly 

 woody, biennial, prickly, trailing, 1-8 m. long, usually unbranched the first 

 year, but bearing numerous short flowering branches the second year; leaves 

 3-foliolate, rarely 5-foliolate; leaflets ovate, mostly acute, rounded or cordate 

 at base, doubly and somewhat incisely dentate, pubescent especially beneath, 

 2-5 cm. long; calyx glandular and prickly; petals white, 1-2 times as long as 

 the acute somewhat foliaceous tipped sepals; fruit black when ripe, cylindrical, 

 1-3 cm. long, finely flavored. 



Abundant, especially in " burns"; commonly known as " blackberry." 



Rubus nivalis Dougl. Stems trailing, armed with weak prickles; leaves 

 ovate-cordate, 3-lobed or rarely 3-foliolate, serrate, shining; petals " lurid 

 red"; fruit bright red, hemispherical, acid. 



In mountain woods, rarely blooming. 



Rubus oarviflorus Nutt. Thimble Berry. Stems wholly unarmed, peren- 

 t^ ^ nial, 1-1.5 m. high; bark brownish, becoming shreddy, usually glandular- 

 A) pubescent when young; leaves palmately and acutely 5-lobed, irregularly 

 serrate, cordate at base, soft-pubescent or nearly glabrous, 10-30 cm. broad; 

 petioles about as long as the blades, with stipules; corymbs few-flowered; 

 calyx glandular and woolly; petals white, about 2 cm. long; fruit red, flat- 

 convex, juicy, about 2 cm. broad. 

 In open woods, abundant. 



Rubus laciniatus Willd. Evergreen Blackberry. Stems climbing, 3-5 m. 

 long, armed with numerous stout recurved prickles; leaflets 3, pinnately cleft 

 or parted and laciniately incised, sparsely pubescent beneath; petioles prickly; 

 flowers in small corymbs; sepals pubescent and armed with straight prickles; 

 petals white or pinkish, often incisely cleft; fruit a blackberry. 



Cultivated and commonly established as an escape making dense thickets. 



Rubus spectabilis Pursh. Salmon-berry. Stems 1-3 m. high, armed with 

 weak prickles; leaves mostly 3-foliolate; leaflets ovate, acute or acuminate, 

 coarsely serrate, often lobed; flowers red, mostly solitary; fruit a raspberry, 

 yellow or dark-red. 



In swamps and along streams. Two varieties occur, one the better- 

 flavored with salmon-yellow fruits, the other with reddish-black fruits. The 

 latter is also distinguishable by the purple color of the twigs. The young 

 fleshy shoots are sweet and are often eaten by children and were formerly used 

 as food by the Indians. 



Rubus leucodermis Dougl. Blackcap. Erect shrubs, the biennial stems 

 1-2 m. high, very glaucous, armed with stout straight or curved prickles; 

 leaves 3-foliolate, rarely 5-foliolate; leaflets ovate, acuminate, doubly ser- 

 rulate, white-pubescent benjeath, the lateral ones oblique and frequently with 

 one or two lobes; petioles and midveins prickly; flowers small, in few-flowered 

 corymbs; petals white, small, erect, shorter than the reflexed sepals; fruit 

 nearly black when mature, hemispherical, glaucous or tomentose, about 1 cm. 

 broad. 



In open woods. Young shoots sweet and edible. 



273. ROSA. ROSE. 



Erect or climbing shrubs, usually with prickly stems; leaves 

 alternate, odd-pinnate, with adherent stipules; leaflets mostly 

 serrate; flowers solitary or in corymbs; calyx- tube cup- or urn- 

 shaped, becoming fleshy in fruit, usually 5-lobed, without bractlets; 

 petals 5, large, obcordate; stamens numerous, on the calyx-tube; 



