332 BRITISH FLOWERING PLANTS chap. 



Melittis 



Protandrous. Adapted to humble bees and moths. 



M. Melissophyllum. — In some districts the corolla is 

 white, in others pale purple, in others red or white with 

 purple spots. The flowers are very sweet. The corolla- 

 tube is 25-35 mm. in length and sometimes half filled 

 with nectar. It varies in colour in different countries, 

 being white in Southern Tyrol, purplish white in Lower 

 Austria and Hungary. 



Marrubium (Horehound) 



M. vulgare. — The ten teeth of the calyx curve back, 

 forming hooks, which facilitate the scattering of the 

 nutlets. The plant bears long soft hairs. 



Stachys (Woundwort) 



S. sylvatica has protandrous flowers. The corolla- 

 tube, 1 1 mm. long, is often filled with nectar to a depth 

 of 2-3 mm. 



S. palustris is also protandrous. The corolla-tube is 

 7-9 mm. long. The anthers of the outer stamens are 

 open first and lie in front of the others. After shedding 

 their pollen they turn outwards, while the inner stamens 

 elongate and their anthers open at the same place. 

 Then the pistil elongates and the stigma presses itself 

 between the anthers. The leaves are finely hairy. The 

 stem bears reflexed hairs on the edges. 



S. arvensis is homogamous. According to Kirchner 

 there is very little, if any nectar. The corolla-tube is 

 only 4 mm. in length. 



S. annua, an alien which has become established 

 in corn-fields in Kent, has homogamous flowers. The 

 corolla-tube is 8-10 mm. in length. The leaves are 

 glabrous or slightly hairy. 



S. germanica. — Besides the complete flowers this 

 species has others in which the stamens are rudimentary. 

 These are often on special plants. The plant is covered 

 with a white tomentum. 



