Flora of the Palouse Region 95 



much branched, 10-20 cm. long: flowers small, white, becoming yellowish: 

 calyx densely short-pubescent, obscurely 5-9-lobed; the lobes dentate, 

 spreading. Snake River canyon. 



154. RUBUS. 



Perennial herbs or shrubs, often prickly: leaves alternate, 

 simple or pinnately 3-7-foliolate, with stipules adherent to the 

 petiole: flowers white or reddish, solitary or in racemes or corymbs: 

 calyx 5-lobed, without bractlets: petals 5, conspicuous: stamens 

 indefinite, on the calyx-tube: styles nearly terminal; carpels num- 

 erous, on the convex receptacle: carpels drupaceous, 1 -seeded. 



Fruit separating from the receptacle when ripe. 



Leaves simple. R. nutkanus. 



Leaves compound: stems bristly. R. STRIGOSUS. 

 Leaves compound: stem prickly, glaucous. 



Leaves white beneath. R. LEUCODERMis. 



Leaves green beneath. R. HESPERIUS. 

 Fruit not separating from the receptacle when ripe: trailing shrubs. 



R. MACROPETALUS 



R. nutkanus Moc. Stems wholly unarmed, perennial, 1-1.5 m. high: 

 bark brownish, becoming shreddy, usually glandular-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 woolly: petals white, 

 about 2 cm. long: Iruit red, low-convex, juicy, about 2 cm. broad. Thatuna 

 Hills, common in open woods, rare away from timber. 



R. strigOSUS Michx. Stems erect, biennial, 1-2 m. high, densely armed 

 with weak, glandular bristles or sometimes nearly unarmed: leaves mostly 

 3-foliolate, rarely 5-foliolate; leaflets ovate, acuminate, simply or doubly 

 dentate, rounded at base, thin, usually white-tomentose beneath, glabrous 

 above, 2-6 cm. long: corymbs few-flowered: calyx usually pubescent and 

 bristly: petals white, about as long as the acuminate sepals: fruit hemispher- 

 ical, light red. Thatuna Hills, rare. 



R. leucodermis Dougl. Erect shrubs; the biennial stems 1-2 m. high, 

 very glaucous, armed with stout straight or curved prickles: leaves 3, rarely 

 5-foliolate; leaflets ovate, acuminate, doubly serrulate, white-pubescent be- 

 neath, the lateral ones oblique and frequently with one or two lcbes; 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. Thatuna Hills, 

 rare; also along Snake River. 



R. hesperius Piper. Much like the preceding but with more numerous 

 stouter straight or curved prickles: leaves green and glabrous on both sides: 

 berries black, glabrous. Snake River canyon. Both this and the preceding 

 are perhaps better considered mere varieties of R. occidentalis L. of the 

 Eastern states. 



R. macropetalus Dougl. Stems slightly woody, biennial, prickly, trail- 

 ing, 1-8 in. long, usually unbranched the first year, but bearing numerous 

 short flowering branches the second year: leaves 3-foliolate, rarely 5-foliol- 



