Of Aphyllon Unifiorum, Gray. 117 
bundle-strands enter each lobe singly, but immediately divide 
into three main branches. 
The upper lip of the tubular corolla consists of two some- 
what recurved lobes, the lower of three lobes. Each lobe is 
supported by two main strands of bundle-tissue, which enter 
separately as branches of the bundle-ring in the floor of the 
flower. The outer surface of the corolla bears many hairs 
above the line where the calyx lies against it, the inner surface 
not nearly so many. These hairs are all of the same type, 
having a stalk of several cells placed end to end, and a round 
head formed of (usually) eight radially arranged cells. The 
four epipetalous stamens are didynamous, the posterior pair 
being the shorter. The anther-lobes are formed in the usual 
way, having at first four and later two loculi. The micro- 
spores are small and spherical. 
The unilocular ovary consists of antero-posterior carpels. 
Externally it is quadrangular in shape, corresponding to the 
positions of the four placentas, and the style bends forward 
so that the broad bilcbed stigma lies at the anterior part 
of the mouth of the flower-tube. At the base of the ante- 
rior carpel is a large nectary sunk into the tissues of the 
carpel (Plate XV, Fig. 7). In cross section the ovary shows 
an epidermal layer of high columnar cells, the outer walls of 
which are thickened. Within are several (four or five) layers 
of rounded cells. The four parietal placentas are cushion-like 
ingrowths of similar rounded cells, the entire ovarian wall being 
packed with starch. A well-marked bundle-strand is present 
in the middle of each carpel, the position of the bundle being 
indicated externally by anterior and posterior grooves on the 
surface of the ovary. The small anatropous ovules are pro- 
duced in great numbers (Plate XIV, Fig. 4). 
The nectary shows in cross section seven to nine layers of 
gland cells, which are readily distinguishable by their small 
size, rounded outline, the absence of starch, their granular, 
