1922] 



PFEIFFER MONOGRAPH OF THE ISOETACEAE 83 



The technical name for the genus seems to be in common use. 

 By derivation, it indicates the evergreen character of at least 

 some of the species "equal at all seasons of the year" or through- 

 out the year, from icoc, equal, and troc, year. Some forms are, 

 however, false to the name in that no leaves, sterile or otherwise, 

 seem to survive the winter or dry season. The perennial char- 

 acter of the corm is not to be doubted in such plants though 

 the leaves do disappear. 



In the older accounts, it is of interest that an economic relation 

 was usually mentioned. So Ray (1696) says that the plant 

 "gives out a melancholy fluid, used in affections of the spleen 

 and liver. It is accredited somehow with sharing the habit of 

 the plants with which it grows." Dillenius, on the other hand, 

 cites as its use that the plant is eaten by fish. 



That birds are not disinterested in the food use of Isoetes is 

 evidenced by the story of Durieu, who first saw /. histrix bulbs 

 under rather unusual circumstances. 1 The peculiar organs were 

 found in the stomach of a bird which was shot down by a mem- 

 ber of his party. The real nature of the plant structures was only 

 recognized in subsequent field work when similar bulbs were 

 discovered growing on the hillsides of Algeria. That a terres- 

 trial form resembling this Algerian plant, 7. Duriaei, is eagerly 

 devoured by pigs, is also quoted from the statements of Bory de 

 Saint-Vincent. 



In the eastern United States, one observer says that ducks are 

 fond of the bulbs or sporangia masses at the base of the plant and 

 will tweak them off, allowing the leaves to float. Clute says 

 of 7. Braunii Dur. that the crisp bulbs are favorite morsels with 

 muskrats, and that cattle are said to feed upon the leaves of any 

 species available. 



The corms are said to have been eaten occasionally in Europe 

 by human beings, though the taste is variously described as 

 earthy and unpalatable (Clute) or acid and bad-tasting (Delile). 

 Undoubtedly the presence of starch and oil give the spores and 

 corms food value, whether they be palatable or not. The dis- 

 tribution hardly seems extensive enough to make consideration 

 of development of a taste for them worthy of attention. The 

 plants probably are of greatest economic use at present as a 

 source of food for the lower animals mentioned. 



VBory de Saint-Vincent, Stir les Isoetes et les especes nouvelles de cette 

 famille decouvertes en Algerie. Compt. Rend. Acad. Paris 18: 1167. 1844. 



