26 



FARLOW ON THE GYMNOSPORANGIA 



usually 7-8 together ; peridia cylindrical, contracted at the base, brownish- white, an eighth 

 of an inch long, composed throughout of long, sinuous, smooth-walled cells, 12u-15u in 

 diameter, which cohere at the apex and separate below in meshes so that the peridium is 

 clathrate. Spores brownish, 15u-19/j, in diameter, epispore slightly granular, pores indis- 

 tinct. Spermogonia few in number in the depressed upper part of the leaves. 

 On the leaves of Amelanchier canadensis. 



Eastern Massachusetts (Farlow) ; Newfield, N. J. (Ellis) ; Bethlehem, Pa. (Schweinitz). 



A striking species which does not mature until the middle of September or the first of 

 October, the spermogonia appearing in the latter part of August. It is distinguished from 

 our other species by the large-sized tubercles which appear in dense clusters on the under 

 surfaces of the leaves, from which protrude the long peridia which resemble those of R. 

 cancellata in having the cells coherent at the apex and separate below, so that the peridium 

 becomes clathrate, the spores being discharged through the meshes. The peridia, how- 

 ever, are less hroad and bulging than in R. cancellata and the microscopic character of the 

 cells is very different. In R. botryapites they are longer and more slender than in any 

 of our other species, and the cell-walls are destitute of the papillose or granular markings 

 found in most of the species. They are also so sinuous and so long that an accurate meas- 

 urement of their length is out of the question. The different cells, instead of overlapping 

 at the extremities as in R. cancellata, fit closely together, and the apical cells, instead of 

 being shorter and broader than those below as in the species last named, are of about the 

 same breadth and shape throughout. In fact, so narrow and smooth are the cells and so 

 closely are they united to one another at the extremities that, on seeing them for the first 

 time under the microscope, one would be more likely to suppose them to be some brownish 

 mycelium than a collection of peridial cells. The spores of R. botryapites are, on the 

 average, smaller than those of our other species. The fungus forms reddish-yellow spots 

 on the leaves of Amelanchier in which the spermogonia are developed in comparatively 

 small numbers, and when the swollen masses of the leaf in which the aecidia are borne 

 appear, the upper surface bearing the spermogonia becomes depressed. The tubercular 

 masses are much contracted at the base, and when fully mature they drop from the leaves, 

 only a small scar remaining. The cells of the tubercles abound in starch grains, in this 

 respect resembling R. cancellata. 



The present species is very common in Eastern Massachusetts and has probably a wider 

 range than one would infer from the very few recorded localities. It is frequently seen in 

 entomological collections, and the large tubercles with their small bases certainly remind 

 one more strongly of insect galls than the work of fungi, at least until the peridia have 

 protruded. The Schweinitzian species remained for a long time obscure, but it was redis- 

 covered by Ellis at Newfield, N. J., and named by Peck G. Ellisii. Berkeley is quoted in 

 Grevillea, loc. cit., as having ascertained the identity of the two species from the examina- 

 tion of an original specimen of Schweinitz. There is a specimen from Schweinitz in Herb. 

 Curtis, but the peridia and spores are not mature. As far, however, as can be judged from 

 its present condition, it seems to be the same as specimens collected by Ellis. 



