INCREASE OF THE FOOD SUPPLY No. 72 



DETAILED DESCRIPTION OF PLANTS BY R. B. THOMSON. 



As mentioned above I visited Whitewater Lake, near Sudbury, in the latter 

 part of September, 1912, to study .the plant food which the Northern lakes afford 

 for ducks and collect specimens for illustration. With the exceptions noted under 

 the figures, all the specimens shown are from Whitewater Lake. 



In considering plants as food material it must be recognized that at one season 

 of the year one part of a plant may contain a greater proportion of the food material 

 than at another. For instance, a perennial withdraws its food material from the 

 leaves in the autumn, and stores it in the stem or roots. Again, in the formation 

 of the fruit much of the reserve of food finds its way into this region, the seed 

 usually being packed with starch and other food materials. 



DESCRIPTION OF PLANTS. 



As a plant that is an important food for deep water ducks all through the 

 season, first place must be given to the form so successfully introduced into White- 

 water Lake, the so-called Wild Celery of duck hunters, illustrated in Fig. 1. 



This plant (Vallisneria spiralis] is known by several other common names, 

 Tape-grass, Eel-grass, etc. It is a submerged aquatic plant with long grass-like 

 leaves about a half -inch wide and from a foot to a foot and a half in length. These 

 leaves have three rather distinct veins running from the base to the tip, and here 

 and there some transverse ones, which, no doubt, are responsible for the name 

 Tape-grass, which is most frequently applied to the plant. These leaves all come 

 from a very short stem, just as in the ordinary celery of the garden, with which, 

 however, the plant has no botanical relationship, the whiteness of the leaves at 

 their base and their crispness having, no doubt, given rise to the name wild 

 celery. The roots of the plant are attached in a great bunch (see Fig.) just below 

 the crown, from which the leaves come off. Their fibres penetrate the loose mud 

 or sand at the bottom of the still water where this plant thrives. 



Vallisneria has two very efficient methods of propagation. Runners (see Fig.) 

 :ome from these plants in numbers, and from these a series of young plants arise. 

 I have found five on one runner in a specimen from Whitewater Lake, though the 

 one figured has but two attached to it. Just as in the strawberry, these young plants 

 are smaller the farther they are from the mother plant. Their leaves are very crisp 

 and delicate and form a valuable food for the ducks. 



The plant is propagated by seed also. About the middle of August a long 

 thread comes to the surface bearing the minute white flowers at the apex. One 

 plant (the male) produces only pollen-bearing flowers, which will form no seed, 

 while another plant has flowers which will bear the seed if they have Feen fertilized 

 by the pollen from the other plant. The male flower usually breaks away from its 

 anchoring thread and floats around among the female flowers, setting free its masses 

 of pollen 011 the surface of the water. This reaches the female flower and .fertilizes 

 it, after which seed sets in the female flower and the male disorganizes. In most 

 plants the pollen is carried by the wind or insects, but in the case of Vallisneria 

 the pollen floats on the water from the one flower to the other. About the middle of 

 September the thread supporting the female flower begins to coil into a loose spiral 

 (from which the plant derives its scientific name) and the seed pod is drawn down 

 from the surface. At this time of year the pod is usually about 2-3 inches in length 

 and full of a jelly-like substance in which are incased the host of yellowish imma- 

 ture seeds. By October the pods have become 3 to 5 inches in length and very 



