ae ea ee ee 
290 PHARMACEUTICAL BOTANY 
Tue SticMA.—This is usually a viscid papillose surface of 
greater or less expanse functioning for pollen reception. If no 
style intervenes between the ovary and stigma, the stigma is said 
to be SEssILE, as in the poppy. 
In wind-pollinated flowers 
such as the grasses, the stigmas 
are the numerous feathery hairs 
which cover the ends of the styles 
and are intended to catch flying 
pollen grains. Such stigmas are 
called plumose. In animal-pol- 
linated flowers, the stigmas are 
usually small restricted knobs, 
lines or depressions. The stig- 
matic papille vary in size in 
different plants and even may 
vary on different individuals of 
the same species. Thus, in the 
long styles of Primula, the stig- 
matic papillae are elongated, 
Fic. 219.—Trimorphism and hetero- columnar, hair-like structures, 
styly, a means of insuring cross pollina- Whereas in the short styles of 
tion. The three forms of flowers in the short-styled flowers the papillae 
loosestrife (Lythrum salicaria). The are small knob-like cellular 
corollas and calyces are omitted in order : 
swellings. 
to show the different lengths of stamens 
and styles. The functional crosses are Various terms are ascribed to 
indicated by the arrows. (Fram Dar- stigmas to denote their shape, 
win’s ‘Cross Pollination,’ Courtesy of ‘ : 
D. Appleton & Co.) lobing, markings, appendages, 
etc. Among the more common 
of these are capitate, referring to a spheroidal stigma, bifid, or two- 
lobed, truncate, when cut square off at the tip, annular, or ringed 
below the summit, penicillate or brush-like, barbellate, having 
minute barbs, etc. 
POLLINATION 
PouinaTIoN is the transfer of pollen from anther to stigma 
and the consequent germination thereon. It is a necessary step 
to fertilization. 
