418 BRITISH FLOWEKING PLANTS chap. 



TULIPA (Tulip) 



Some with, some without nectar. 



T. sylvestris. — The flowers are yellow, homogamous, 

 and sweet-scented. Nectar is secreted at the base of 

 the stamens, and protected by a tuft of hairs. The 

 yellow stigma projects beyond the stamens, and secretes 

 drops of sweet fluid. The flowers are principally visited 

 by small bees (Andrena and Halictus) which lick up 

 the fluid on the stigma before they explore the recesses 

 of the flower. The flower gradually droops, so that 

 finally the stigma comes within the fall line of the 

 pollen. 



Lloydia 



Protandrous flowers with free honey. 



L. serotina. — Nectar is secreted by a ridge at the base 

 of the perianth. In Britain it only occurs on some of 

 the Welsh mountains. 



Gagea 



Scentless flowers with exposed or half- concealed 

 nectar, secreted at the base of the flower. According 

 to Schulz sometimes the stamens, and sometimes the 

 pistil, fail to develop. 



G. lutea. — The flowers are slightly protogynous. 

 According to Kerner the stamens contract after shed- 

 ding their pollen. 



Ornithogalum 



Flowers with half-concealed honey, secreted by 3 

 glands contained in the septa of the ovary. 



Three species occur in Britain : O. umbellatum has 

 the flowers in a corymb, the other two in racemes ; in 

 0. nutans they are few and large, in 0. pyrenaicum 

 many and small. 



0. umbellatum (Star of Bethlehem). — The flowers are 

 protogynous and borne in a corymb ; the spreading peri- 

 anth segments are white, with an outer broad green band. 

 The stigma is ripe when the flower expands, then, accord- 



