PHARMACEUTICAL BOTANY 



Style. The style is the portion of the carpel which connects the 

 stigma with the ovary. It is usually thread-like but may also be con- 

 siderably thickened. It frequently divides into branches in its upper 

 part. These are called style arms. As many style arms as carpels 

 may be present. In the one-carpelled pistil of some Leguminosa, the 

 usually bent-up style is the tapered prolongation of a single flower. 

 Again, in the apocarpous carpels of many flowers of the Ranuncul- 

 acea, each carpel bears a short to long stylar prolongation. When 

 the carpels, however, are syncarpous the common 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 gynoecium. 



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 Cam- 

 panulacea 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 stig- 

 mas then curl apart to expose their viscid stigma tic hairs. In this 

 instance there are two distinct and at separate times functioning 

 hairs on the stylar prolongation, 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 into a short column bearing a tuft of hairs that prevents 

 the entrance of insect thieves into the flower. In the genus Iris 

 the common style breaks up at the insertion of the perianth into 

 three wide petaloid style arms. Each of these bifurcates at its ex- 

 tremity. On the lower or outer face of this is a transverse flap that 

 bears the stigmatic papillae. 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 portion with five 

 radiating ribs. At the extremity of each bifid end of each rib is a 

 minute peg-like stigmatic surface. 



