SOUR GRASSES 43 



Arundo phragmites (reeds). Aira s. W eingaertneria canescens (silver gra,ss — 

 Europe). Molinia coeriilea (Europe). Nardus stricta (bristle grass — Europe). 

 Ammophila s. Calamagrostis arenaria (mat grass or sand reed). 



As compared with the meadow grasses, the so-called sour grasses 

 have a very low feeding value, and when ingested in quantities are liable 

 to affect the health, especially that of the digestive organs. 



Organs — Koenig ascribes their injurious effect to the presence of nauseating 

 volatile oil, but more recent investigations have shown that these co-called grasses 

 contain large quantities of silicic acid in their tissues, even in the early stages of 

 growth, and especially in the leaves, which owe their rough character to the presence 

 of silica. The latter acts as a mechanical irritant to the mucous membranes of 

 the digestive tract and leads to digestive disturbances and even active inflammation. 

 Holy observed increased excretion of albumin in the urine and proteid substances in 

 the fecal discharges. Under these conditions the tissues must suffer from albumin 

 starvation. The incrustation of the sour grasses with silica also interferes with 

 the action of the digestive fluids. 



The various species of the sour grasses should not, however, be re- 

 garded as of equal inferiority. Some of them are indeed less inferior 

 than some of the sweet grasses, especially the felty fruited Carex tomcn- 

 tosa; the millet sedge, C. Panic ea; the dioecious sedge, C. dioeca; the 

 rush, Juncus botniciis; and the two species of Triglochin (arrow grass), 

 T. maritimum and T. palustris*. The latter are regarded as first-class 

 forages and are highly prized, especially as feed for milk cows. They 

 contain only small quantities of silicic acid in the cell walls and compara- 

 tively few silicious spicules on the edges of the leaves. On the other 

 hand there are sweet grasses which are provided with well-developed 

 silicious spicules on the edges of the leaves and a needle-like pubesence 

 on the leaf surfaces, making them just as objectionable as the sour 

 grasses. Giant fescue grass is of this nature, as well as some other 

 species. Among the sour grasses Carex canescens, C. pallescens and C. 

 pilulifera (all European species) are considered of medium value as 

 forage. Among the rushes (Juncace-^e) the species of the genus Luziila 

 (wood and field rushes) have the same reputation. The latter are preva- 

 lent in the United States. 



The horsetails (Equisetaceae) are similar to the sour grasses in feeding 

 value. They are found in damp, swampy and boggy meadows. The 

 common swamp horsetail (Equisetum palustre) is a very inferior forage, 

 and has, in addition, an unfavorable effect upon milk secretion, espe- 

 cially in horses. According to some authors it is said to have toxic 

 qualities. On the other hand E. limosum (pipes) and E. heleocharis 

 (often very abundant on the borders of ponds) are prized as good for- 

 age for milk cows (not for horses). E. limosum is common in ,the 

 United States on borders of ponds and swamps and is greedily devoured 

 by cattle and sheep. 



Among the herbaceous meadow forage plants the Leguminosse, and 

 particularly the different species of clover and the vetches, Lathyrus 



4A11 of these sour grasses seem to be European species, except T. maritimum and T. palustris, 

 which are also indigenous in the United States, where cattle are fond of them, especially T. 

 maritimum, which grows on salt marches and lake shores. — Translator. 



