ROSACEAE (ROSE FAMILY) 251 



16. RUBUS L. RASPBERRIES AND BLACKBERRIES 



Mostly prickly shrubs or sometimes almost herbaceous plants, with tri- 

 foliolate or pinnately compound leaves, with adnate stipules. Flowers white 

 or purple, in panicles or corymbs or sometimes solitary. Receptacle conical, 

 hemispherical, or nipple-shaped. Sepals and petals 5. Stamens numerous. 

 Styles filiform ; carpels numerous, becoming drupelets and forming an aggre- 

 gate fruit on the fleshy receptacle. Ours are RASPBERRIES in which the fruit 

 separates from the receptacle; in the BLACKBERRIES the receptacle and the 

 carpels detach together. 



Stems herbaceous; prickles often wanting 1. R. americanus. 



Stems woody, very prickly 2. R. strigosus. 



1. Rubus americanus (Pers.) Brit. Mem. Torr. Club 5: 185. 1894. Stems 

 short, trailing or ascending, unarmed: leaves few, of 3-5 rhombic-ovate or 

 ovate-lanceolate, doubly-serrate, thin smooth leaflets, 2-4 cm. long: peduncle 

 1-3-flowered: petals small, white: fruit small, of few red drupelets. R. tri- 

 florus.Said to occur in Colorado; from northern Wyoming east to the Atlan- 

 tic. 



2. Rubus strigosus Michx. Fl. Bor. Am. 1: 297. 1803. Stems biennial, 

 woody, erect, prickly with stiff straight bristles, glandular when young, 

 somewhat glaucous: leaflets oblong-ovate, incisely serrate, whitish-pubescent 

 below, the lateral ones sessile: petals as long as the sepals: receptacle oblong: 

 fruit hemispherical, light red, of excellent flavor. The WILD RED RASPBERRY. 

 Throughout the Rocky Mountains and eastward. 



16. DASIOPHORA Raf. SHRUBBY CINQUEFOIL 



A freely branching shrub; the branchlets often slender. Leaves pinnate, 

 the small leaflets with entire margins; stipules scarious, sheathing. Calyx 

 salvor-form, with 5 bractlets alternating with the 5 sepals. Petals 5. Sta- 

 mens about 20. Style clavate, glandular upward, inserted near the base of 

 the ovary; stigma large, 4-lobed. Achene densely villous, as is also the re- 

 ceptacle. Potentilla in part. 



1. Dasiophora fruticosa (L.) Rydb. Mem. Dept. Bot. Columbia Univ. 

 2: 188. is'.ts. A freely branched shrub, 3-10 dm. high, silky-villous: leaves 

 pinnate; leaflets 5-7, linear-lanceolate, entire, rather crowded, usually white 

 beneath and the margins revolute: flowers terminal, cymose or solitary: 

 petals yellow, 15-25 mm. broad, longer than the ovate calyx-lobes and bract- 

 lets. Potentilla fruticosa. Creek banks and boggy ground; throughout the 

 Rocky Mountains and across the continent to the northward; also in Europe 

 and Asia. 



17. SIBBALDIA L. 



Dwarf and caespitose arctic or alpine perennials, with thick trifoliolate stip- 

 ulate leaves and cymose flowers on scape-like nearly leafless peduncles. Leaf- 

 lets few-toothed at the truncate summit. Calyx persistent, nearly flat, with 

 5 sepals and 5 bractlets. Petals 5, yellow, narrow, minute. Carpels 5-10, 

 on a dry receptacle; style lateral. 



1. Sibbaldia procumbens L. Sp. PI. 284. 1753. Densely tufted, the creep- 

 ing stems 5-20 cm. long, leafy at the extremities: leaflets obovate-cuneate, 

 somewhat villous: peduncles about equaling the leaves: petals shorter than 

 the sepals: achenes on very short hairy stipes. North in the mountains from 

 Colorado, and then across the continent. 



18. FRAGARIA L. STRAWBERRY 



niferous perennials 

 tufted at the base and having mem 



Acaulescent stoloniferous perennials, with palmately trifoliolate leaves 



lembranous stipules, and white cymose 



