12._0N THE SYSTEMATIC POSITION OF .EC ID 11] M 

 ELEGAXS DIET. 



By I. B. Pole Evans, B.A., B.Sc, F.L.S. 



A little more than thirty years ago Prof. MacOwan — the pioneer 

 of South African mycology— collected an secidium on Rhanmcs pri- 

 noides in the Somerset East district of Cape Colony. This fungus was 

 at that time considered to be the a^cidial form of Piiccinia conrnata 

 Corda ; for we find that Saccardo includes Jihamnus j>rinoidfi.^ among 

 the hosts on which the fiecidium of Pnccinia corouata Corda occurs. 

 Some ten years later, in 1888, Dietel described this ;v^cidium, and named 

 it ^Ecidi-iim ^let/aiis Diet 



Saccardo's description of ^Ecidium elcijonx Diet, in his ■''^y^^'xj'i 

 FiiAiiforimi is as follows : — 



'■'■ .Ecidium deyan>i Diet. Hedw. 1888, p. 180. Pseudoperidiis 

 hypophyllis, parce gregariis vel solitariis, elongato-cylindraceis, circ. 

 1 mm. long., margine indivisis vel leviter constrictis, siccis dilute 

 cerinis ; a^cidiosporis irregulariter polyhedricis, plerumque "Jo-.SI^ 

 diam., siccis h3'alinis, membrana spissa minute verruculosa, apice 

 saepe incrassata (usque ad 13^ cr.). 



" Hab. ad Rhamnum prinoidem, Caput Bonae Spei Afr. austr. 

 (MacOwan)." 



My examination of this lecidium tigrees exactly with the abuve 

 descripti<:)n so far as it goes, but I must point out that no mention 

 whatever is made of the spermogonia which I find occur regularly with 

 this R'cidium. They occur mostly on the upper surface of the leaf, and 

 are usufdly found in conjunction with an ;ecidium on the opposite side, 

 though they fre(|uently occur singly. They measure 180^ in diameter. 

 The spermatia ave hyaline, elliptical, barely 3^ long. 



While exaniining the spores contained within the a'cidium, I took 

 the opportunity of observing their germination behaviour, and was sur- 

 prised to find tliat instead of germinating as ordinary jecifliospores with 

 a single ger)n tube, they one and all gei-minated regularly as teleuto- 

 spores. Each spore gave rise to a shoit pro)nycelium consisting of four 

 cells, from each of which a single pear-sliaped sporidiolum wa.s soon 

 budded off. The sporidola not infrp(|UPntly germinated at once while 

 still attached to the pro)nycelium 



These facts throw new light on the nature of the fungus u)ider 

 considei'ation and consequently give us the clue as to its jeal systematic 

 positio)!. It must be referred to the geiuis Eiidophyllum, which is 

 characterised by its single-celled teleutospores originating in chains 

 within a pseudo-peridium. These spores germinate as typical Pnccinia 

 teleutospores. 



On this account, therefore, I propose that this fungus be referred 

 to the genus Endo])hyllvm witli the specific distinction MacO>rani, in 



