ON VINCA 



177 



punctiform, brownish, often very numerous, scattered over the 

 whole leaf-surface, sweet-scented, spherical, about 175 /x diam. 



Uredospores. Sori hypophyllous, pallid-brown, of two kinds ; 

 primary irregular, often elongated and curved, crowded and 

 confluent, naked ; secondary scattered, on roundish dirty-brown 

 spots, long covered by the epidermis; spores globose to pyriform, 

 aculeate, pallid-brown, 20 — 32 /x diam. or 20 — 46x16 — 24 ll, 

 with three germ-pores. 



Fig. 127. P. Vincae. a, teleutospore, seen dry ; b, the same, seen wet ; 

 c, uredospore ; d, the so-called a?cidia. On Vinca major, all x GOO. 



Teleutospores. Sori hypophyllous, on scarcely perceptible 

 or conspicuous spots, minute, scattered or in groups, roundish 

 or irregular, surrounded or half-covered by the torn epidermis, 

 pulverulent, dark-brown ; spores ellipsoid to oblong, rounded at 

 both ends or attenuated downwards, hardly thickened at apex 

 but with a pale papilla, not at all or faintly constricted, scrobi- 

 culate, ochreous-brown, 35 — 54x18 — 27 /x ; epispore 3 — 4 ll 

 thick ; pedicels hyaline, deciduous, rather long. 



On Vinca major, V. minor. Not common. Spermogones in 

 April ; uredospores, May — June ; teleutospores, July — October. 

 (Fig. 127.) 



This is one of the most remarkable species of Puccinia found in Britain. 

 There is considerable difference of opinion about its structure. The bodies 

 referred to in the description given by Plowright (I.e. p. 161) as "aecidia" are 

 of a puzzling nature : they are not described by Sydow or Fischer, but are 

 mistakenly considered by them as identical with the primary uredo-sori. 

 They accompany the spermogones on the under side of the leaves, and 

 are flatly pulvinate subepidermal erumpent sori, surrounded by the erect 



G. u. 12 



