THE FLOWER 289 
styles tend to become more or less fused but usually show lobes, 
clefts or style arms at their extremities that indicate the number 
of carpels in each case which form the gyncecium. 
In some plants remarkable variations from the typical stylar 
development may occur. Thus, in Viola, the end of the style is a 
swollen knob on the under surface of which is a concave stigma 
with a flap or peg. In the genus 
Canna, the style is an elongate, blade- 
like, flattened body with a sub-terminal 
stigma. In forms of the Campanulacea, 
the style is closely covered with so- 
called collecting hairs. On these the 
anthers deposit their pollen at an early 
period before the flowers have opened. 
Later, when the flowers open, insects 
remove the pollen after which the 
collecting hairs wither. The stigmas 
then curl apart to expose their viscid 
stigmatic hairs. In this instance there 
are two distinct and at separate times 
functioning hairs on the stylar prolon- 
gation, viz.: (a) collecting stylar hairs, 
functioning for pollen collection and 
distribution; and (b) stigmatic hairs for 
pollen reception from another flower. 
In Vinca, the style swells near its 
extremity into a broad circular stigma 
and then is prolonged intoa short column 
bearing a tuft of hairs that prevents the 
Fic. 218.—Lilium Martagon. 
Longitudinal section of the 
stigma and upper part of the 
style. The pollen grains, 
caught on the papillze of the 
stigma, have germinated, and 
the pollen-tubes are growing 
down along the walls of the 
style canal. (From Gager after 
Dodel-Port.) 
entrance of insect thieves into the flower. In the genus Jris, the 
common style breaks up at the insertion of the perianth into three, 
wide, petaloid, stylearms. Each of these bifurcates at its extrem- 
ity. On the lower or outer face of this is a transverse flap that 
bears the stigmatic papilla. In Physostigma, the style enlarges at 
its extremity into a flap-like swelling which bears a narrow 
stigmatic surface. Finally, in Sarracenia, the single style of the 
five-carpelled pistil enlarges above into a huge umbrella-like por- 
tion with five radiating ribs. At the extremity of each bifid end 
of each rib is a minute, peg-like, stigmatic surface. 
