118 Journal op the Mitchell Society [June 



processes are in the form of low, small, rounded cushions crowded 

 all around the infected area and are in large part fused into a con- 

 tinuous mass. Teliospores thicker than in our other species, 17-23 x 

 40-55/x, the upper cell with a single apical pore, the lower with a pore 

 by the pedicel through which the germ-tube may emerge or it may 

 emerge through the pedicel scar itself. The pedicel is stout, slightly 

 swollen a little below the spore, 7-11/x thick at point of attachment. 

 The aecial stage is on the shad-bush (Amelanchier), affecting the 

 fruits as much or more than the leaves. The infected fruits reach 

 nearly full size and turn reddish where not attacked, but are dis- 

 torted and imperfect. A tree in the garden at Glen Burnie is infected 

 every year. 



2786«. On twigs and small branches of cedar, April 9, 1918. Photo. 



3. Gymnosporangium Nidus-avis Thaxter. 



Plates 31 and 52 



This is not uncommon in Chapel Hill, making rough and un- 

 sightly areas and scars on the branches and rarely even on the trunks 

 of cedar. The gelatinous outgrowths are crowded in longitudinal 

 rows often all around the branches for a distance at times of several 

 feet. The branch is not much swollen, but the rough surface due to 

 the ruptured bark makes such places larger. The individual scars 

 are usually oval and about 2-4 x 4-7 mm., approximated by the scars 

 of the preceding years. Gelatinous processes (telia) wedge-shaped, 

 chestnut brown, 7-15 mm. high. 



Teliospores (of No. 2772a) two-celled, 13-18.5 x 37-58,^, the two 

 cells often partly separated before sprouting, the upper sprouting 

 apically or at the septum or from both places, the lower from near 

 the septum in one or two places, the slender pedicels not swollen. 



This plant does not agree well with Gymnosporangium Nidus-avis 

 as described in North Am. Flora (I.e. p. 196), which is said to have 

 larger teliospores with stouter pedicels, the upper cell sprouting api- 

 cally, the lower at the septum (called "apically" also). But Dr. 

 Kern writes me that he would call our plant G. Nidus-avis. He says : 

 "As regards the pores in the teliospores of Gymnosporangium the 

 arrangement is quite variable. The generic description in the North 

 American Flora states that they are usually 2 in each cell, but some- 

 times 1, 3, or 4, variously arranged, often near the septa, sometimes 



