SYSTEMATIC BOTANY: 179 
flowers in a sessile umbel, styles combined below, fruit glo- 
bose. 
Pyrus torminalis (Wild Service-tree); leaves ovate or 
cordate, lobed, and serrated, lower lobes spreading, pe- 
- duncles corymbose. 
Pyrus domestica (True Service-tree) ; leaves pinnated, 
downy beneath, leaflets serrated upwards, flowers panicled, 
fruit obovate. 
- Pyrus aucuparia (Quicken-tree, Mountain-ash, or Rowan- 
tree); leaves pinnated glabrous, leaflets serrated, flowers 
corymbose, fruit (small) globose. 
Pyrus pinnatifida* (Bastard Mountain-ash); leaves en- 
tire, pinnatifid and pinnated, white and downy beneath, 
flowers corymbose, fruit globose. 
_ -Pyrus Aria (White Beam-tree) ; leaves ovate, cut and ser- 
rated, white and downy beneath, flowers corymbose, fruit 
_ globose. 
The following description of the genus Rose, and the 
species Dog-Rose, will show more precisely the meaning of 
the term “ variety” in Systematic Botany. 
ROSA, (ROSE.) 
Generic Character.—Calyx urn-shaped, fleshy, contracted 
at the orifice, terminating in five segments. Petals five. 
Pericarps (or carpels) numerous, bristly, fixed to the inside 
of the calyx. ‘ 
Rosa canina (Common Dog-Rose); prickles uniform, 
hooked, leaves naked or slightly hairy, their disk eglandu- : 
lose, calyx-segments fully pinnate deciduous, styles not 
- United, shoots assurgent. 
* Some of the leaves of this plant so nearly resemble the following (Pyrus 
_ Gia), “ that I fear (and ProfessorHenslow is of the same opinion) iteanonly 
be considered a variety."—Dr. Hooker; from whose British Flora the above” 
characters of Pyrus, and the following of Rosa, are taken. z 
