PLATE 52. 



ERGOT ON COUCH. RYE AND TIMOTHY, 



Claviceps purpurea (Fr.) Tul., and other species. 



(Noxious : Dom.) 



There are often found in certain seasons among the grains of rye, rarely 

 among those of wheat, and abundantly among the seeds of some grasses, 

 dark-coloured solid bodies of characteristic form in each species of grain or 

 seed. These are of a doughy consistency, and when broken are purplish white 

 inside. They are the storage organs or resting stage of a parasitic fungus 

 or perhaps the several species of fungi belonging to the genus Claviceps. 

 Each of these solid bodies is called a sclerotium (plural sclcrotia) derived 

 from a Greek word skleeros, hard or dry, in allusion to the nature of these 

 bodies. They are practically masses of the vegetative system or "spawn" nf 

 the fungus in a resting condition, but capable of growth in spring when 

 placed under favourable conditions of warmth and moisture, such as they 

 get when sown with crop seed or when lying on the ground at the bases of 

 the stems on which they were formed the previous summer. At the proper time 

 in spring very small toadstool-like bodies on violet stalks with round orange- 

 coloured heads about the size of mustard seeds, are produced from the sclero- 

 tia lying on the ground, which develop enormous numbers of microscopically 

 small spores (organs analogous to the seeds of higher plants). These are pro- 

 duced at the time that grasses and grains are in flower. The minute spores, 

 carried by currents of air or by insects, lodge in the flowers of the grasses 

 and begin to grow ; in a short time they completely destroy the seed and 

 form from them the sclerotia. These vary in shape according to the plant 

 they attack. In rye and Couch Grass they are long and horn-like, over 1 inch 

 in length, frequently much larger than shown in our figure of Couch Grass. 

 In wheat and Wild Rice they are shorter and thicker ; in timothy and June 

 Grass very small, \ of an inch long, slender and almost black. During the 

 summer, summer spores are formed on these horns, and also at the same time 

 a sugary secretion very attractive to insects which, coming to the infested 

 plants, carry off on their bodies many of the summer spores to the flowering 

 heads of other grasses they visit, and in that way spread the infection. Late 

 in summer the production of summer spores stops, and the sclerotia or st"or- 

 age organs begin to store up a special kind of starch found only in fungi 

 and known as fungus starch, as well as oils to serve as food for the growth 

 of the fruiting organs to be sent out the following spring ; they then harden 

 up, turn dark purple in colour and fall to the ground or are carried with the 

 grain or hay. 



The sclerotia are common on a great many grasses and particularly on 

 rye, wheat, barley and Wild Rice, as well as on Western Couch Grass and 

 other prairie grasses cut for hay. They all contain an alkaloid and other 

 violent poisons. Rome are used in medicine under the name of "Ergot of 

 Rye." Bread made from flour containing ergot may cause a serious disease 

 known as ergotism in those that eat it ; and animals which feed on grain 

 or hay containiiig ergot, may also bo severely poisoned, as is sometimes the 

 case on our western plains. One well-known result of cattle eating ergotised 

 hay is abortion. 



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