20 THE PLANT WORLD. 



ally small, one-seeded nutlets, often curiously crested or ridged. 

 There is little satisfaction in collecting these aquatics, uuless one can 

 spare time to float each plant out carefully upon a sheet of white paper, 

 when they are, indeed, beautiful objects for study. 



The Arrowheads [Alismacea:) are distinguished from the preced- 

 ing families which we have examined by having in the majority of 

 cases a manifest white perianth surrounding the stamens and pistils. 

 In Alisjna, the water-plantain, this is small; but in Sagittaria and its 

 allies the three white petals are large and of the texture of crepe, so 

 that a bog full of these plants presents a beautiful sight in the sun- 

 light with their spikes of delicate flowers and arrow- or halberd-like 

 leaves. From sad experience one will learn the futility of attempting 

 to gather a bouquet of Arrowheads. There are about a dozen genera 

 in this family, and over sixty species, the bulk of them occurring in 

 the deep swamps of tropical regions. The leaves are entirely basal, 

 not produced along the stem as in the Pondweeds ; and the flowers are 

 borne in loose clusters or panicles, not in close spikes, with their parts 

 in threes; they are sometimes perfect, but more often the staminate 

 and pistillate flowers are separate on the same plant, which is expressed 

 by the term monoecious in botany. 



One little family, chiefly exotic, contains the well-known "tape- 

 grass" or " eel-grass" of fresh and brackish waters, the long, ribbon- 

 like strands of which are often seen cast up along the shore, and form 

 the chief food of the wild ducks in the Chesapeake Bay. This plant, 

 Vailisneria, illustrates the characters of the Val/isneriacecE, or Tape- 

 grass family, in being a submerged aquatic with flowers having an 

 inconspicuous perianth, the staminate and pistillate chiefly borne on 

 separate plants (dioecious). The fruit, as in most of these water- 

 weeds, is nut-like. 



In the next article we will attempt to distinguish between the 

 grasses, sedges and rushes. 



Earle, in a charming little volume on "English Plant Names," 

 has the following to say in regard to the study of the vernacular or 

 common names of plants: "The fascination of plant names has its 

 foundation in two instincts, love of Nature, and curiosity about Lan- 

 guage. Plant names are often of the highest antiquity, and more or 

 less common to the whole stream of related nations. Could we pene- 

 trate to the original suggestive idea that called forth the name, it 

 would bring valuable information about the first openings of the 

 human mind towards Nature ; and the merest dream of such discovery 

 invests with a strange charm the words that could tell, if we could 

 understand, so much of the forgotten infancy of the human race." 



