104 MICROSCOPIC FUXGI. 



and stems are covered^ from tlie bean rust [Triclio- 

 basis Fahce, Lev.), wliicli in like manner is con- 

 sidered as tlie simple stage or form of tlie bean 

 brand (Fuccinia Fahce, Lk.), the true bilocular 

 spores of whicli we have never succeeded in finding 

 or seeing. Beans tliorouglily infected with this 

 rust or brand are seldom of much service in either 

 field or garden. 



Beetroot, or mangold wurzel, is another example 

 of garden and field produce which is subject to a 

 similar visitation. This rust often has very red 

 spores when produced on red varieties of beet. 

 During September, 1863, it {Trichohasis Betce,\jQY.) 

 was sent us on the leaves of the wild beet [Beta 

 maritima). 



All the species of Polygonum are exceedingly 

 subject to the attacks of the Persicaria rust {Tri- 

 chohasis Folygonorum, B.), which nearly covers the 

 leaves, till the entire plants seem to be smothered 

 in Scotch snuS". If it were allowable to affii^m of 

 any plants that they are martyrs to parasitism, such 

 might be said of the Persicarias and their allies. 



Sedges are subject to the attacks of a rust much 

 resembling the corn rust. When it occurs on some 

 species of Gar ex, the upper surface of the leaf has 

 corresponding pale spots, and the pustules them- 

 selves are surrounded by a yellowish margin. This 

 species (Trichohasis caricina) is far from uncommon 

 (plate VIII. figs. 170, 171). The sedge-Hke plants 

 belonging to the genus Luzula have also their own 



