GYMNOSPOKANGIUM 



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JEcidiospores. yEcidia hypophyllous, on the same spots, flask- 

 shaped, 1 — 2 mm. broad, pale-brown, 

 split to the base into lacinise which 

 remain united at the summit, and at 

 first are joined at intervals by short 

 transverse bands ; spores finely verru- 

 culose, brown, 28 — 30 /u. (average). 



Teleutospores. Spore-masses on 

 the branches, at first pulvinate, dark- 

 brown, then irregularly conical, 8 — 

 10 mm. high, red-brown, gelatinous; 

 spores of two kinds, thick-walled and 

 thin-walled, broadly and obtusely bi- 

 conical, scarcely constricted, smooth, 

 brown, 40 — 50 x 25 — 30 ^ ; germ-pores 

 four, two in each cell. 



^Ecidia on Pyrus communis, July — 

 September; teleutospores on Juniper us 

 Sabina, April and May. Not uncommon 



Fig. 234. G.Sabinae. Groups 

 of fecidia on leaf of Pear. 



(Fig. 234.) 



This is said to occur on other species of Pyrus and Juniperus. The 

 life-history is similar to that of the other Gymnosporangia. The sperruo- 

 gones are said by Fischer to have occurred on the fruit of the Pear ; 

 other authors record the secidia on both the young fruits and the petioles. 

 The eecidia are easily distinguishable from all the others, the upper part of 

 the peridium, after dehiscence, looking very like the calyptra of Polytrichum; 

 but the teleutospores are similar to those of G. confusum, the chief 

 difference being that the thick-walled spores of the latter are rounded 

 at the summit, not bluntly conical. 



In this, as in all the similar cases, when the secidium is found on 

 its host, search should he made in the neighbourhood for the alternate 

 host ; the Juniper is often found in a neighbouring gai-den. Since it 

 is always the teleutospore-mycelium that is perennial, the only successful 

 remedy for this plant-disease is to destroy and burn the Juniper, or 

 at least the affected part ; it is useless to spray the tecidial host. 



Distribution : Europe. 



