iv.] WILLOW. 33 



separate plants (dioecious). In the Lesser Nettle staminate 

 and pistillate flowers are on the same plant (monoecious}. 

 Examine the staminate and pistillate flowers separately. 

 In the staminate flowers you observe the calyx to consist 

 of 4 sepals. As the corolla is suppressed, the envelope of 



FIG. 22. Staminate or male ( <J) flower FIG. 23. Pistillate or female 



of Stinging Nettle. ( 9 ) flower of same 



the flower is single (inonochlamydeous), not double (di- 

 chlamydeous)) as in all the species hitherto examined. 

 Opposite to the sepals are the four stamens, inserted upon 

 the receptacle (hypogynous). The pistil is represented 

 by a minute, central rudiment. In the pistillate flower 

 the calyx consists, as in the staminate one, of 4 leaves, 

 but they are here unequal, an opposite pair being larger. 

 There are no stamens, and the pistil consists, apparently, 

 of a single carpel with a superior ovary, occupying the 

 centre of the flower. 



In the Nettle, then, we have the flowers -.unisexual or 

 diclinous, being monoecious or dioecious according to the 

 species ; the calyx inferior, polysepalous j corolla o ; in 

 the male flower, stamens hypogynous, tetrandrous, pistil 

 o ; in the female flower, pistil apocarpous and sttperior, 

 stamens o. The calyx of monochlamydeous plants is 

 usually termed a perianth. 



12. WILLOW. Any species will do ; but, as in the case 

 of the Greater Nettle, two specimens from different trees 

 will be required, as the flowers are declinous and dioecious. 

 The cuts represent the male and female flowers of the 

 Great Sallow. You find the flowers arranged in spikes, 

 which, being desiduous and bearing imperfect flowers, are 

 especially distinguished as catkins. Both the staminate 



O.B. D 



