WAYSIDES AND WASTES IN SPRING 107 



one side, just before the flowers begin to mature, exposing the 

 club of the spathe. Tlie club is thick and fleshy, and coloured 

 either dull purple, bright red, pink, or yellow. The pistillate flowers 

 are clustered round the bottom of the spadix, and consist of a 

 number of sessile ovaries. Above them is a ring of imperfect 

 flowers consisting of styles only, and above these again is the cluster 

 of staminate flowers, with some aborted stamens at the top. After 

 fertilisation has taken place the spathe and the spadix soon wither 

 away, and the ovaries develop into a cluster of large berry-Uke 

 fruits, each containing a few seeds. These fruits, mounted on the 

 summit of the lengthened, fleshy peduncle, are very conspicuous 

 objects in the autumn hedgerows. 



The contrivance by wliich cross -fertilisation is secured in these 

 flowers is particularly interesting : — Numbers of little insects 

 (midges) are attracted by the brightly coloured club, and, possibly, 

 also by the foetid odour of the flowers. These creep down the 

 spadix, passing through the narrow neck into the closed compart- 

 ment below. Tlie neck is more or less obstructed by the upper, 

 abortive, staminate flowers, which consist merely of a few whorls 

 of bristles. Since, however, many of these bristles point downwards, 

 they offer but little obstruction to insects as they enter ; but 

 prevent theii- escape. Thus, on cutting open the lower part of the 

 spathe, we may frequently find quite a number of midges that 

 have been imprisoned, their bodies covered with pollen that has 

 probably been carried from another Ai'um previously visited. The 

 pistillate flowers are mature first, and thus the imprisoned insects, 

 creeping about in thek cell during this early stage of the flower, 

 are sure to bring poUen cells in contact with some of the ripened 

 stigmas. 



After the work of fertilisation has been accomplished, the anthers 

 ripen, setting free abundance of pollen which now covers tlie bodies 

 of the insects in the place of that which has been rubbed on to the 

 stigmas. Then the abortive stamens, which prevented the escape 

 of the insects, wither ; and, at the same time, the neck of the spathe 

 relaxes. Tlius the prisoners are again set free, and possibly a large 

 proportion of them enter another flower and repeat the process 

 of cross-pollination. 



The commonest of the early-flowering Grasses of the wayside 

 is the Annual Meadow Grass {Poa annua) — a small tufted species, 

 varying from a few inches to nearly a foot in height. It commences 

 to flower in March, and remains in bloom till the end of the summer. 

 j^ is represented on Plate III. 



