44 THE BOOK OF NATURE STUDY 



flattened, and the dense spike of sessile flowers, which is the 

 termination of the stem, looks like a projection by the side of 

 the leaf-like bract, which in this genus does not enclose the 

 inflorescence as the bract (spathe) of the Arum does. The spike 

 contains many hundred flowers, which do not produce ripe fruit, 

 probably because there are not the right insects to pollinate it in 

 this country, as it does produce fruit in Asia, its native continent. 

 The Bur-Reeds and the Bulrushes belong to the Typhaceae. 

 There are three well-marked species of Bur-Reed (genus Spar- 

 ganium) in the British Isles. The largest, Sparganium ramosum, 

 is easily recognised by the flower stem branched near the top ; 

 the branches are given off alternately on each side, each bearing 

 six or more heads of flowers protected by a leafy bract. The 

 upper heads contain staminate, the lower, pistillate flowers. 

 The Simple Bur-Reed (S. simplex) has an unbranched flower 

 stem ; the flower-heads are fewer and at considerable distances 

 from each other ; the lower stalked ones produce fruit, the upper 

 ones are barren. The Small Bur-Reed (S. minimum) is a very 

 much smaller plant, with narrow leaves that float on the surface. 

 It is not as common as the other two species, and belongs to still 

 water rather than to rivers. 



The Bulrushes are, strictly speaking, Reed-Maces (genus 

 Typha). The Great Reed-Mace (T. lati folia) has a short root- 

 stock which creeps in the mud and from which erect stems, three 

 to six feet in height, ascend. The leaves may be as much as ten 

 feet in length, though five or six is their usual height. The spike 

 of flowers is often more than a foot in length, the staminate 

 flowers being above the pistillate. In the smaller species of Reed- 

 Mace (T. angmtifolia) there is a distinct interval between the 

 two sets of flowers. When the flower-spikes first appear among 

 the sheathing leaves they are wrapped in long bracts almost 

 lace-like in their delicacy ; as the flowers develop, these bracts 

 float off in the air. It is well worth watching them. The fruits 

 are brown, and persist during the winter. When they become 

 detached from the spike, the hairs borne by the stalk of each 

 fruit act as wings to disperse the seed ; the hairs fluff out into 

 downy masses, so that the whole spike looks about a hundred 

 times as large, for a single head will contain about a quarter of a 



