THE DICOTYLEDONES 1933 



In general the three anterior petals form a lip while the two posterior 

 petals form an arched hood, protecting and enclosing the stamens and 

 stigma. The number of stamens is either four, or reduced to two. 



Fig. i860. — Alonarda didytiia. Bergamot. 

 Inflorescence, with coloured bracts. 



The flowers are often brightly coloured, generally blue or red, and are 

 adapted to butterfly- and moth-pollination, though most of the British 

 species have shorter tubes and are adapted to pollination by bees. Cleisto- 

 gamic flowers are found in Salvia and Laniiiim, while in Lycopus virginicus 

 autumn flowers occur which are buried below the soil, where fruits are 

 produced as a result of self-pollination. 



The genus Salvia (Fig. 1861) shows an elaborate pollination mechanism 

 which varies somewhat in diflerent species. The flowers are generally 

 protandrous and are adapted to pollination by humble bees or hive bees. 

 In iS". pratensis (Fig. 1862) the corolla is bright blue in colour and is directed 

 horizontally. The nectar is secreted by the fleshy base of the ovary. The 

 lower lip of the corolla forms a platform while the upper lip serves to protect 

 the fertile anther lobes. 



The flowers are protandrous and have two fertile stamens only, with 

 short filaments which are inserted on the corolla tube. Each filament 

 bears a versatile anther with a transversely elongated connective. One 

 limb of the connective is very long and turned upwards, bearing a fertile 

 half-anther which is hidden below the upper corolla lip. The other limb of 

 the connective is much shorter, points downwards and ends in a sterile 

 plate of tissue, lying across the entrance to the basal, tubular part of the 

 corolla. The sterile plates of the two stamens are joined and in the normal 



