i8o 



Puccini a Geraniaceae. 



X. Mesospores occasional, similarly coloured, subglobose, thickened at 

 apex, 25-26 fj. diam. 



On living leaves of Geranium pilosum Sol. 



Victoria Killara, Nov., 1902, II., March, 1903, II., EIL (Robin- 

 son). 

 New South Wales Richmond (Musson). 



Occasionally a teleutospore occurs in which the septum is vertical as in 

 Diorchidium. 



In the recorded species of Puccinia on Geranium there are only teleu- 

 tospores with the exception of P. callaguensis Neger, on leaves of Geranium 

 berterianum Colla, in Chili. 



It differs from this species however in the teleutospores being smooth 

 and not minutely verrucose, and in the elongated pedicel. 



The host-plant is variously named. It is found in all the Australian 

 States, and was called G. pilosum by Solander. 



In the Index Kewensis it is given as a synonym of G. dissectum, but 

 the late Baron von Mueller used the name of G. pilosum, considering it 

 "more exact than that of G. carolinianum and G. dissectum" 



F. M. Bailey, in his Queensland Flora, divides G. dissectum into two 

 principal races, one of which is pilosum. 



The species of Puccinia found upon it is new, and while it is not cus- 

 tomary to determine a host-plant from the species of rust found upon it, 

 still in this instance it lends probability to the view that we are here dealing 

 with an indigenous form of Geranium, differing from G. dissectum. For 

 this reason I have not followed the Index Kewensis in naming the host. 



(Plate XII., Figs. 103, 104.) 



Pelargonium* 



114. Puccinia morrisoni McAlp. 



I. Aecidia amphigenous, delicate, minute, orange, circinate, either alone 



or accompanied by teleutospores ; pseud operidia with expanded and 

 lobed margin ; peridial cells subquadrate to oblong with striated 

 margin, and punctate all over, firmly united, 28-32 x 16-22 p. 



Aecidiospores pale orange, finely echinulate, elliptic to subquad- 

 rate, 19-22 x 16 p, or 18-19 p diam. 



II. Uredosori mostly on under surface of leaf, round, small, brownish, 



pulverulent, solitary or arranged in confluent groups. 



Uredospores subglobose to ellipsoid, yellowish brown, echinulate, 

 22-24 p diam., or 22-27 x 19-22 p. 



III. Teleutosori intermixed, solitary or arranged in small confluent 

 groups, generally round, black, compact, surrounded by ruptured 

 epidermis. 



Teleutospores chestnut brown, clavate, constricted at septum, 

 smooth, often obliquely pointed or rounded and thickened 

 at apex (up to 9 p), 33-64 x 19-25 p, average 45 x 22 p ; 

 lower cell usually paler in colour and attenuated towards base ; 

 pedicels tinted, generally short, persistent, up to 3Sp long by 6-9 p 

 broad. 



X. Mesospores coloured like teleutospores, oblong to oval, bluntly 

 pointed and thickened at apex, 33-38 X 16-20 p. 



