240 



PUCCINIA 



Spermogones. Epiphyllous, in roundish clusters, 

 . Ecidiospores. /Ecidia epiphyllous, on roundish yellow spots, 

 in orbicular clusters as much as 1 cm. diam. surrounding a 



group of sperinogones. seutellifonn, yellow, with a slightly and 

 irregularly torn narrow margin; spores delicately verruculose, 

 orange, 12 — 20 p. 



Uredospores. Sori scattered or in rows, often confluent, 

 oblong, elliptical or linear, long covered by the swollen epidermis 

 which is at length longitudinally split, ferruginous; spores 

 subglobose to ovoid, often flattened on one side, echinulate, 

 pale-brown, 19 — 32 x 12 — 24 /a, with two germ-pores. 



Fig. ls.5. P. Scirpi. Teleutospores and mesospore, from the original 

 specimens, Kind's Lynn (ex herb. Plowright). 



Teleutospores. Sori similar, generally numerous and con- 

 fluent, black-brown ; spores oblong or subclavate, thickened 

 above (5 — 9 /x) and rounded, truncate, or subcorneal, hardly 

 constricted, attenuated downwards, smooth, brown, 30 — 60 x 

 12 — 24 ijl: pedicels yellowish, persistent, 25 — 45 /x long; meso- 

 spores more or less abundant, 24 — 40 \x long. 



^Ecidia on leaves of IAmnanihemum ( Villarsia) nymphaeoides 

 ( Nymphoides peltatum), July: uredo- and teleutospores on culms 

 of Scirpus lacustris, July — November. Rare ; King's Lynn ; 

 Dear Earith (Huntingdonshire). (Fig. 185.) 



Plowright suggested in 1889 (Monograph, p. 191) that this I'xrci/iia 

 was most likely a hetercecious species. Chodat was led, in 1891, to suspect 

 the Limnanthemum as the alternate host, by finding the two stages both 

 together in the same pond in the Botanic Gardens at Geneva. Klebahn 



