WIND POLLINATION 305 



Palms — a list in which lofty forest-trees are conspicuous 

 — and also Grasses, Sedges, Rushes, Reeds, Nettles, 

 Plantains, Hops, Hemp, and Pondweeds. Trees which, 

 like the Birch, Hazel, and Alder, have a catkinate in- 

 florescence are mostly anemophilous. Take, for example 

 the Hazel (Fig. 67, p. 207). In this instance, male and 

 female catkins are borne on the same plant. In early 

 spring the male catkins open and lengthen, and on fine, 

 dry days liberate a shower of pollen. This is light and 

 powdery, and remains suspended in the air for a con- 

 siderable length of time. The female catkins are not 

 nearly so conspicuous as the male. They appear almost 

 like buds tipped with red, but on closer examination are 

 found to consist of a number of female flowers, each 

 having a two-celled ovary, with two styles tipped with 

 red stigmas. The combined stigmas of all the flowers 

 protrude at the apex of the catkin in the form of a 

 feathery tuft, which presents a surface of sufficient area 

 to catch a few pollen grains when they are drifted to- 

 wards it on a current of air. The Hazel nuts that we 

 look for in autumn are the products of fertilization. 

 Most catkinate trees, like the Hazel, produce flowers 

 before leaves, or when the leaves are not so far developed 

 as to present a serious obstacle to the drifting pollen. 

 It is obvious that if the Hazel were in full foliage at the 

 time of flowering, the leaves would render the chance of 

 the pollen reaching the stigmas very remote. 



Wind-pollinated plants produce modest flowers. Not 

 desiring the services of insects, they waste no strength 

 in making showy petals. They display no gaily coloured 

 advertisement, and produce no honey. But their male 

 flowers manufacture pollen in vast quantity, and shed 



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