BIOLOGY OF THE FLOWER 



183 



five stamens alternating with the corolla-lobes ; the large 

 anthers are joined into a tube round the style and form 

 a conspicuous yellow cone, above which projects the two- 

 lobed stigma. When ripe the anthers dehisce by pores 

 at their free ends (Fig. 125, 3). 

 The pistil is superior, and 

 consists of two united carpels 

 placed obliquely in the flower 

 (Fig. 173) ; the ovary is two- 

 celled with many ovules on 

 axile placentas. The flower 

 secretes no honey, but is 

 visited by bees for pollen. 



Irregular and specialized 

 flowers. The Germander 

 Speedwell (Fig. 126) is pol- 

 linated mainly by drone-flies, 

 and shows several interesting 

 modifications. The flower (2 

 and 3) has four sepals, the 

 fifth posterior one being ab- 

 sent. The blue corolla has 

 four petals, but the large 

 posterior one really represents 

 two fused petals. All are 

 joined into a short tube. 

 There are only two stamens, 

 and these spread out hori- 

 zontally. The pistil consists 

 of two united carpels, and the 

 style projects over the anterior petal. A fleshy disk below 

 the ovary secretes honey, which is protected from rain by 

 hairs on the corolla. 



As the fly alights, it first touches the stigma, then grasps 

 the two stamens, pulling them to the sides of its body, 



Fig. 126. 1, Germander 

 Speedwell ; 2, flower showing 

 the position of the stamens and 

 style ; 3, flower in vertical 

 section ; a, stamens ; br, bracts ; 

 /, opposite decussate leaves : 

 r, raceme ; st, style. 



