736 FUNGI 



The teleutospores, which are arranged in long fine streaks on the 

 leaf-sheaths, haulm and chaff, have 

 short stalks and germinate in the 

 autumn of the year during which 

 they are produced. The cells of each 

 individual teleutospore are usually 

 superposed unsymmetrically, the 

 upper one being frequently flattened 



F,0..49.-^.Td=ut»poreof/'«.. ^^ the tOp (A, Fig. 249). 



cinm giumarum Schm. ; B, teieuto- .iEcidiospores are uuknown. Five 



spore of Fucctnui coronata Corda. > ^ _ 



c, teleutospore of Pticcinia. simpUx ' biological Varieties ' are recognised, 



Kom. (Enlarged about 350 diameters.) ° . , ,. , 



namely (i) var. tritici on wheat ; (li) 

 var. hordei on barley; (iii) var. secalis on rye; (iv) van agrofyri 

 on Agropyrum repens ; (v) var. elymi on Elytnus arenarius. 



(b) Brown ' rust ' {Puccinia dispersa Eriks. et Henn.). — The 

 aecidiospores of this species are produced in Autumn on 

 Bugloss {Anchusa officinalis L.) and Alkanet {Anchusa arvensis 

 Bieb.) 



The uredo-sori are a pale brown or raw sieima tint and dis- 

 tributed irregularly all over the leaves of the host-cereal ; they 

 are not usually seen until a short time before harvest. The 

 teleutospores, which resemble those of P. glumarum, ait com- 

 monly most prevalent on the under side of the leaves, and 

 remain largely covered by the epidermis of the latter. Four 

 biological varieties of the fungus are known, namely on (i) wheat, 

 (ii) rye, (iii) couch-grass and (iv) brome-grasses. 



{c) Puccinia simplex Korn. — This species, which attacks barley 

 only, is of little practical importance as the damage it causes 

 is usually slight. Its uredo-sori are very small, lemon yellow 

 in colour and distributed irregularly on the infected leaf. The 

 teleutospores are generally one-celled (C, Fig. 249). 



(d) Crown * rusts.' — Two species of crown ' rusts ' are known, 

 namely Puccinia coronifera Kleb., and P. coronata Corda. The 

 upper cells of the teleutospores in both species are surmounted 



