25. 
26. 
27. 
28. 
29. 
30. 
dl. 
32. 
33. 
34. 
35. 
36. 
37. 
38. 
39. 
40. 
41. 
| 42. 
Yarrow 
Oxeye daisy . 
Dandelion 
Barberry . 
Mountain laurel 
White clover. 
Red clover 
Locust . 
Wistaria 
Vetch . 
Pea . 
Bean 
Ground-nut . 
Partridge-berry . 
Primrose . 
Loosestrife 
Milkweed ; 
Lady’s-slipper 
ECOLOGY OF FLOWERS 
369 
Ill 
Achillea millefolium Miill. 
Chrysanthemum en ee Miill. 
Taraxacum officinale Miill., Newell. 
IV 
.. Berberis vulgaris . . Lubbock. 
Kalmia latifolia . Gray. 
V 
Trifolium repens . Miill. 
Trifolium pratense Mill. 
Robinia Pseudacacia Gray. 
Wistaria sinensis Gray. 
Vicia cracca Miill. 
Pisum sativum Mill. 
Phaseolus vulgaris Gray. 
Apios tuberosa Gray. 
VI 
Mitchella repens : Gray. 
Primula grandiflora, P. cmlethatie . Lubbock. 
Lythrum Salicaria . Gray. 
VII 
Asclepias Cornuti Miill., Newell. 
VIII 
Cypripedium acaule Newell. 
439. Cleistogamous Flowers. — In marked contrast with 
such flowers as those discussed in the preceding sections, 
which bid for insect visitors or expose their pollen to be 
blown about by the wind, are certain flowers which remain 
closed even during the pollination of the stigma. 
These 
flowers are called cleistogamous and of course are not 
