Bethel: Gymnosporangium in Colorado J 57 



It was a great disappointment not to get culture material of 

 Gymnosporangium speciosum, as noted below in discussion of 

 Aecidium gracilens. However, this arduous trip of five hun- 

 dred miles was amply rewarded by the discovery of an unique 

 species, apparently undescribed, which causes the dense, globose 

 "witches' brooms" (2 in. to 2 ft. in diameter) on the Utah 

 cedar (Juniperus utahensis). The cause of these conspicuous 

 "brooms" has been attributed to some one of the numerous 

 insects, such as coccids, aphids, etc., which inhabit them. The 

 writer, however, has for some years entertained the belief that 

 they were due to a species of Gymnosporangium but has been 

 unable to verify this suspicion until this spring on account of not 

 being able to visit the region at the proper season to make collec- 

 tions. An examination of the " brooms " at this time revealed 

 the fact that a small Gymnosporangium, somewhat resembling 

 G. Nelsoni, was the cause of the fasciation, and that the pres- 

 ence of the insects is merely incidental, as they find convenient 

 shelter among the compact branchlets. This interesting species, 

 conspicuous on account of the fasciation it produces, is charac- 

 terized as follows: 



Gymnosporangium Kernianum sp. nov. 



Telia arising between the scale-like leaves, causing a fascia- 

 tion of the young shoots and forming dense, globose " witches' 

 brooms " 5-60 cm. in diameter ; sori scattered, solitary, hemi- 

 spheric, 0.5-0.8 mm. across, rather compact, dark reddish- 

 brown; spores usually two-celled, narrowly ellipsoid, large, 21- 

 26 X 55-74 as only slightly or not at all constricted at the sep- 

 tum ; wall thin, about 1 /x, yellowish, smooth ; pedicel hyaline, 

 cylindric, very long ; pores usually two, near the septum. 



On Juniperus (Sabina) utahensis (Engelm.) Lemm., Paonia, 

 Colorado {type), March 28, 1911; Glenwood Springs, Colorado, 

 March 27, 191 1, E. Bethel Type deposited at the New York 

 Botanical Garden. 



This species produces a very compact, perfectly spherical 

 fasciation (see Fig. 2), the numerous branchlets becoming 

 weaker than normal, and the scales smaller, thus differing from 

 the fasciation of G. Nelsoni, in which the scales of the affected 



