THE STRUCTURE OF CERTAIN NEW HYBRIDS. 147 
In C. they are much less stout, almost cylindrical, with five, some- 
times six, well-defined angles, between which are several minor ridges ; 
glaucous green, with a good deal of reddish-purple, which is often confined 
to the ridges. 
In M.W. the branches are rather stouter than in C. and much more 
distinctly angular. There are commonly five angles, one of them being 
less prominent than the rest. The minor ridges are indistinct. Much 
purple coloration exists. 
STIPULES. 
The stipules of B. (fig. 50) are lanceolate, acuminate, slightly oblique, 
4 to ,, in. long, } to ? in. broad, narrowing to the base; the margin almost 
entire, or very inconspicuously serrate. 
In C.* (fig. 52) they are much larger, often more than 1 in. long and 
4, in. broad; in form like a cordate leaf halved longitudinally, the apex 
prolonged into an awn-like point, } in. long. 
In M.W. (fig. 51) the stipules partake of the characters of those 
of both parents in a marked way. They are obliquely ovate, dentate 
Fie. 50.— P. Buonarartea. Fic. 51.—P. Margaret Winson. Fic. 52.—P. c#RULEA. 
SrreuLes (nat. size). ' 
on the longer side, acuminate or ending in a sharp point which is 
usually } in. long. The entire length of the stipule is often § to 1 in., 
and the width} to2in. The largest observed measured 14 in. long 
and 1,), in. broad. 
LEAF-STALKS. 
The leaf-stalks of B. (fig. 58) are strong, 14, to 24 in. long, having one 
sharp mesial ridge along the dorsal (under) side continuous with one of 
the wings of the stem, and a shallow channel on the upper side. The 
upper edges are interrupted by two pairs of light-green sessile glands, the 
one pair being placed about } in. beneath the base of the lamina, and 
the other pair nearly half-way between the upper pair and the base of the 
stalk. The glands are cup-shaped, directed laterally, and in large leaves 
the orifices may measure ,), in. across, 
In C. (fig. 55) the leaf-stalks are sub-cylindrieal, flattened on the upper 
side. They may reach the length of 14 in., and some red coloration is 
commonly present. They bear two, three, or four stalked glands, both 
glands and stalks being dark purplish-green. The stalks are often ;', in. 
long. Their distribution is rather irregular. When only two are present 
* A very careful account of the structure of P. caerulea is given by Sabine, assisted 
by Lindley, loc. cit. pp. 262-265. 
