574 



ROSACEAE 



Rosa 



50 



Map 1172 



Sanguisorba canadensis L 



55 



Map 1173 



Rosa setigera Michx. 



Rosa setigera var. tomentosa T. & G 



the text under the species to which they most nearly approach. It seems 

 best to consider these variables as belonging to "species complexes" rather 

 than to try to assign names to the many variables. 



Styles united; leaves on old stems mostly with 3 leaflets, on new growth 3 or 5; 



stems long, recurved or semi-trailing 1. R. setigera. 



Styles free; leaves on old and new wood mostly with 5, 7, or 9 leaflets; stems erect, or 

 spreading. 

 Orifice (through which the styles protrude) small, 1-2 mm in diameter, surrounded by 

 a well defined disk of fleshy tissue (introduced species). 



Orifice about 2 mm in diameter; leaflets glandular 2. R. rubiginosa. 



Orifice about 1 mm in diameter. 



Leaflets large and leathery, 2-6 cm long, dark green above, pale beneath; stems 

 low and slender; prickles short. (See excluded species no. 376, p. 1064.). . . . 



R. gallica. 



Leaflets small, not leathery, 1.5-4 cm long; stems tall and coarse with large 

 prickles. 



Styles glabrous; leaflets densely glandular and pubescent beneath 



3. R. micrantha. 



Styles pubescent; leaflets not glandular and sparsely pubescent beneath. (See 



excluded species no. 375, p. 1064.) R. canina. 



Orifice in flower and fruit wide, 2-3 mm in diameter. 



Hypanthium usually glandular; calyx lobes generally deciduous from the hips. 



Shrubs of wet ground, usually 1-2 m high; branches reddish; serration of 



leaflets fine; flowers usually corymbose; prickles recurved.. ..4. R. palustris. 



Shrubs of dry uplands, usually less than 1 m high; branches gray or greenish; 



serration of leaflets coarse; flowers solitary on old wood, in terminal corymbs 



on new canes; prickles straight 5. R. Carolina. 



Hypanthium usually smooth; calyx lobes erect and persistent on the hips. 



Stems 0.5-1 m high, usually unarmed except at the base; leaflets 5 or 7, rarely 



9; flowers on two year old stems only 6. R. blanda. 



Stems low, 3-5 dm high, semi-herbaceous, weak and bristly; leaflets usually 9 or 

 11; flowers on old wood and terminally on new shoots 7. R. suffulta. 



1. Rosa setigera Michx. Prairie Rose. Map 1173. This species is dis- 

 tinguished from its variety by having the lower surface of the leaflets 

 glabrous or only the veins pubescent and the upper surface shining. It is 



