OF THE UNITED STATES. 



27 



ROESTELIA TRANSFOUMANS Ell'lS. 



Roestelia transformans Ellis, Bull. Torrcy Club, Vol. v, p. 3 ; Farlow, Bull. Bussey Inst., 

 Vol. n, p. 255. Exsico. Thiimen, Mycoth. Univers., No. 1029. 



Aecidia hypophyllous, or covering the young shoots and fruit, borne in conical protub- 

 erances, occasionally 3-4, generally 5-20 or more together, consolidated at the base ; perid- 

 ium brownish-yellow, a tenth to a twelfth of an inch long, at first conical but soon becom- 

 ing lacerated ; cells of peridium isodiametric at apex, below long and narrow, 12u-15u in 

 diameter, not overlapping on the inner side, cell-wall papillose ; spores globose, brownish, 

 18a-22u in diameter, cell-wall nearly smooth. Spermogonia few in number in purplish- 

 red spots on the upper side of the leaves. 



On the leaves, fruit and young shoots of Pyrus arbutifolia and on the leaves of Pyrus 

 mains. 



Newfield, N. J. (Ellis) ; Newton, Gloucester, Wood's Holl, Mass. (Farlow). 



This species, which occupies an intermediate position between R. botryapites and R. 

 cancellata, is common on Pyrus arbutifolia in Eastern Massachusetts. It occurs in three 

 forms. On the leaves it forms purplish-red spots and the aecidia are generally compara- 

 tively few in number and rather slender. On the fruit they are more numerous and 

 shorter, and when the fungus is found on the young shoots they swell to several times 

 their original size, and become much curved and twisted and take on a yellow color. The 

 number of aecidia produced on the stems is very large. The aecidial protuberances are 

 rather acutely conical and more slender than in either R. botryapites or R. cancellata ; 

 they readily fall from the leaves as in the first-named species. It is only in the young con- 

 dition that the cells of the peridia cohere at the apex, and, as generally seen, the peridia 

 are lacerate. The peridial cells resemble those of R. cancellata but are more slender and 

 do not project inwards. The spores resemble those of R. botryapites. 



What seems to me the same species was collected on apple leaves near the Bussey Insti- 

 tution, Jamaica Plain, Mass., but did not seem to be common. The species is probably 

 common near the sea-shore, but is actually recorded in but few places. It is not likely to 

 escape observation wherever it occurs for the purple spots on the leaves and the distorted 

 shoots are very striking. 



Roestelia cancellata Rebent. 



Roestelia cancellata Rebent, Fl. Neorn., p. 350, PI. n, fig. 9; Curtis, List of Plants of North 

 Carolina, p. 123 ; Oersted, Om en saeregen, etc., PI. n and in ; Reess, loc. cit., p. 20 ; 

 Decades of Maine Fungi, p. 180 ; G-revillea, Vol. v, p. 151. 



Aecidium cancellation Schweinitz, Syn. Fung. Carol., No. 433. 



Caeoma roestelites Ik., Spec. Plant., Vol. vi, part 2, p. 164; Schweinitz, Syn. Fung. Am. 

 Bor., No. 2900. 



Aecidia usually hypophyllous, borne in the swollen tuberculated substance of the leaves, 

 consolidated at the base in clusters of 4-20 ; peridia yellowish-white, a twelfth to an eighth 



