200 



Aecidium 

 mnntanum. 



Parasitic 

 Phanero 

 gams. 



172. The life-history of several 



other rust-fungi exhibit the two stages described above, viz. the 

 Puccinial and Aecidial, but, as our selected example clearly 

 shows, these two stages are not always necessary. Thus there 

 are species of Puccinia of which no Aecidial form is known 

 and vice versa. As an example of an Aecidium of which no 

 puccinial stage is known, we may take the " cluster-cups ' ' so 

 often seen on Berberis Lycium, B. coriaria, and B. aristata, in 

 Jaunsar and near Mussoorie. This species has been named 

 Aecidium montanum. The mycelium of this species is peren- 

 nial, the hyphae running in the cell walls and intercellular spaces 

 of the stem and leaves and obtaining food by means of little 

 finger-like haustoria pushed through the walls. Its presence 

 in the tissues of the Berberis causes the formation of very 

 characteristic witches' brooms. The affected shoots become 

 dwarfed, bear malformed leaves and grow vertically upwards, 

 the long, yellow, aecidial cups occurring in masses on the under- 

 side of the leaves and also scattered on the shoots and 

 sometimes on the peduncles, from which the clouds of powdery 

 orange aecidiospores are shed and disseminated by the wind. 

 Sometimes more than half the bush may be affected in this way. 

 A healthy bush on first infection shows large, reddish, or scarlet, 

 patches on the upper surface and numbers of the long aecidial 

 cups below. In this case there is no deformity beyond a pucker- 

 ing of the leaves, and it is uncertain whether first infection takes 

 place by aecidiospores or by sporidia. If by the latter, the 

 puccinial form bearing the teleutospores is still unknown. 

 This species is distinguished from A. Berberidis by the witches' 

 brooms, by the greater length of the aecidial cups, which may 

 amount to 4 mm., and by the greater size of the patches seen 

 on newly affected normal leaves, which ranges from J to f of 

 an inch in diameter. 



173. The following may be 

 taken as typical examples of parasitic phanerogams : 



(1) Orobanche indica. 



(2) Cuscuta reflexa. 



(3) Loranihus longiflorus. 



(1) Orobanche 

 indica. 



174. The handsome spikes of 



pale purple, or blue, flowers of this plant are often seen 

 in the mustard fields of Northern India, and the total 

 absence of green leaves at once strikes us as peculiar. 



