64 THE SUBSECTION EU-CANINE OF THE GENUS ROSA 
GROUP OF ROSA DUMETORUM., 
: As with the R. canina group, I think it will be conducive to 
idtuplicity to divide this into four subgroups as follows : 
i. Leafiets uniserrate. Peduncles eglandular. 
ii. Leaflets uniserrate. Peduncles glandular. 
iii. Leaflets biserrate. Peduncles eglandular and saints: 
iv. — biserrate. Peduncles glandular or hai 
sn pa S gro up 0 rieties sain iy R. dumetorum ooee ts 
subgroup ii. as ah ified by BR. Desegliset Bor.; subgroups iil. 
cm are his group of varieties nee no special penneriantative: 
which he says approach FR. toment m. 
This group is tolerably well Bataud from those of Rf. canin 
and R. glauca by the presence of hairs on the leaflets, if bp in in 
small quantity on the midribs. The aintinction from BR. coriifolia 
a roa head of densely woolly styles seldom occurring i — 
mt group, but it is not at all easy to distinguish by general 
tasters from f. Borrert. I have given such charac ieaistica as 
I can on p. 13, but seeing that species grouped under Borreri 
often have their seconda nerves eglandular, at least when 
mature, ere is no definite line to be drawn by an 
in certain ~ rsp r at le ast i n individuals, the difficulty of 
ed. 
Subgroup i. Leaflets uniserrate. Peduncles gael 
Key to Britis Spsciss. 
: [resets ib usually somewhat hairy above, and hairy all over beneath 2 
Leaflets eter rarely hairy above, and hairy on midrib or primary 
nerves be: 4 
spate in igs clusters; fruit small. Leaflets long, acute at each 
end. Peduncles occasionally weakly glandular 
R.e erty weiger 
jee solitary or almost. Leaflets obtuse or obi subacute ...... 
angie subacute. Prickles moderate, few, none on — soon 
metorwm Thuill. 
* [Leaflets rain subobtuse. Prickles hooked, meihar t stout. Petioles 
white i. obtusifolia Desv- 
5 
Styles w 6 
BiG ae Leaflets medium R. urbica Lém. 
ruit small, subglobose. Leaflets pe! ie much evended below 
: na var. frondosa Baker. 
es small, straightish. Leaflets sindtan bee hairy on mid- 
se only Laereyee tes ye 
® [Prickles _ hooked. Leaflets large, broad, hairy on mi 
R. platyphylla Piene 
5 
4 | Beles 1 iar or hispid 
