644 



BOTANY OF THE LIVING PLANT 



Later it is strongly recurved, and the stamens then straighten their filaments, 

 carrying their anthers outwards, partly blocking the lower side of the corolla- 

 tube (i. II.). They will thus deposit their pollen on the ventral surface of the 

 visiting insect, conveniently for transfer to the stigma of flowers in the earlier 

 female stage. The posterior stamen from its position could not do this : it 

 is superfluous, and is reduced to a staminode. Cross-pollination is thus highly 

 probable, but self-pollination is possible by pollen falling from the anthers 

 upon the still receptive stigma. 



The Foxglove (Digitalis purpurea, L.) has a similar structure, but its wide 

 bell is suitable for humble bees, the pollen being deposited on their backs. 



Flower of Veronica Chamaedrys, typically pentamerous : but the posterior sepal 

 is abortive : the two obliquely posterior petals are fully fused to form apparently 

 one ; only the two obliquely posterior stamens are developed. 



The flowers are here protandrous. Cross pollination is probable, but self- 

 pollination is still possible. Comparison of the Foxglove with the Figwort 

 shows how, with the same plan of floral construction, there may be differences 

 in the detail and in the agent of cross-pollination. 



(39) The Germander Speedwell (Veronica Chamaedrys, L.) is a common 

 perennial of road-sides and banks. It has long ascending shoots bearing 

 decussate leaves. The racemose inflorescences arise in the axils of the upper 

 leaves. Each flower has a slender stalk, and consists of the following 

 parts 



Calyx, sepals 4, slightly gamosepalous, inferior. Though the number 

 appears to be four, comparison with other species of Veronica, and with other 

 related plants, such as the Foxglove, shows that a fifth sepal, which should be 

 median and posterior, is here wanting (Fig. 495, 11.). 



Corolla, petals apparently four, gamopetalous, inferior, alternating with 

 the sepals and forming a wheel-shaped (rotate) corolla, which readily falls 



