ON CYPERACE 243 
4Aicidiospores. cidia hypophyllous, crowded on red and 
yellow spots, roundish, also in elon- 
gatedclusters on the young branches, 
petioles, and nerves, sometimes en- 
tirely covering the young fruits, 
shortly cylindrical, with broad, re- 
curved, white, much torn margin; 
spores orange, verruculose, 15—21 x 
14—18 p. 
Uredospores. Sori hypophyllous, 
punctiform, about 4mm. long, on 
yellowish spots; spores more or less 
globose, pale-brown, echinulate, 18— Fig. 197, P. Pringsheimiana. 
22 x 17—21y, with three, rarely a Ritespr ie ia 
four, germ-pores. 
Teleutospores. Sori amphigenous, linear or punctiform, up 
to 1 mm, long, pulvinate, brownish-black; spores resembling 
those of P. Caricis, 40—58 x 15—22 yp. 
Adcidia on Ribes Grossularia, R. nigrum (?), May and June, 
common; uredo- and teleutospores on C. acuta, C. caespitosa, 
C. Goodenovit, C. stricta. (Fig. 187.) 
The teleutospore-hosts are those given by Klebahn and Fischer. 
Klebahn first suggested the connection of the wcidium with a Puccinia on 
Carex, and has since demonstrated the truth of this idea by many culture 
experiments. Soppitt also showed the same for Carex acuta and C. Goode- 
novit. The ecidium is said to attack A. alpinum, R. aureum, R. rubrum, 
R. sanguineum, but less frequently. Plowright records the ecidium on 
leaves of Ribes nigrum (Norfolk, June, 1890), but there is no proof that it 
belonged to this species. 
This species is one of those forms originally named by Klebahn 
P. Ribesti-Caricis ; he has since divided them under five heads which can 
scarcely be reckoned anything but biological races :—P. Pringsheimiana, 
P. Ribis-nigri-Acutae, P. Ribis-nigri-Paniculatae, P. Pseudo-cyperi, and 
P. Magnusit (the latter on C. acutiformis and C. riparia). The same 
species of Aibes serve as alternate hosts in each case, in varying degrees 
of susceptibility, except that P. Magnusi is not recorded for R. rubrum 
and &. Grossularia. The morphological differences between these forms 
are slight and elusive. 
P. Pringsheimiana can be distinguished from P. Caricis by its nearly 
16—2 
