8i— ROSA ILLINOIENSIS Baker 
Rosa illmoiensis : caule ramosissimo ; aculeis stramineis, gracilibus, rectis, 
patulis, inaequalibus, interdum geminis ; foliolis 7, parvis, late oblongis, obtusis, 
simpliciter serratis, utrinque glabris ; rhachi parce aciculata, glabra ; stipulis 
angustis, apicibus liberis, ovato-lanceolatis; floribus solitariis ; pedunculis brevibus, 
hispidis ; calycis tubo globoso, parce aciculato ; lobis ovato-lanceolatis, integris, 
dorso glabris ; petalis magnis, albis ; stylis pilosis ; fructu ignoto. 
R. illinoiensis Baker inedit. 
Stems much branched ; prickles straw-coloured, slender, spreading, straight, 
unequal, a few in pairs. Leaflets 7, small, broadly oblong, obtuse, simply serrated, 
i-J in. long, glabrous on both surfaces ; petioles glabrous, slightly aciculate ; stipules 
narrow, with ovate-lanceolate free tips. Flowers solitary ; peduncles short, hispid. 
Calyx-tube globose, slightly aciculate ; lobes ovate-lanceolate, entire, i in. long, 
glabrous on the back. Petals large, pure white, \ in. long. Styles pilose. Fruit 
not seen. 
Rosa illinoiensis is a native of the bare rocky districts of La Salle 
county, Illinois, United States, where it was collected by Green, 
Lansing and Dixon in 1910. It has the habit ol the European Rosa 
spinosissima L,, but its leaflets are only seven in number and its upper 
prickles are arranged in infrastipular pairs. 
243 
LL 
