172 



Arthur: Cultures of Uredineae in 1909 



variation of a single species, as both forms bore prominent dark 

 brown telia of quite similar appearance. The cultures, however, 

 settled the question. Sowings were made of the gall-form March 

 22, on Crataegus punctata giving rise to yellow spots after fifteen 

 days, on which pycnia appeared by April 12, but the leaves ma- 

 tured before aecia could form. Other sowings were made May 

 14 on Crataegus coccinca and C. cerronis, giving rise to a few 

 belated pycnia on the former, first observed June 14, but on tbe 

 latter to an abundance of pycnia May 25 and mature aecia Octo- 

 ber 27. 



This fortunate culture adds another species, with life cycle 

 known, to the Atlantic coast rusts of the common red cedar. It 

 does not appear to be represented in herbaria, either in the aecial 

 or telial form, except by some small unnamed fragments. Pos- 

 sibly collections of aecia have been referred to G. globosum, + 

 which grows on Crataegus, although the peridia difTer in gross 

 appearance. An interesting point is that this species produces 

 cornute aecia, the first to be noticed on Crataegus. The follow- 

 ing name and description have been supplied by Mr. Kern, who 

 has also increased the number of aecial hosts by searching in 

 phanerogamic collections. 



Gymnosporangium trachysorum Kern, sp. nov. 



0. Pycnia epiphyllous, gregarious, in groups 1-2 mm. across, 

 prominent, punctiform, orange-yellow becoming brownish-black, 

 globoid, 144-165/* in diameter by 112-128/* high; ostiolar filaments 

 75-90/x long. 



1. Aecia hypophyllous, rather few in irregular groups 2-5 mm. 

 across, on discolored slightly thickened spots 5-10 mm. or more 

 across, cylindrical, 2-4 mm. high, 0.2-0.3 mrn - m diameter ; perid- 

 ium remaining horn-like, finally rupturing by longitudinal slits 

 along the sides, peridial cells long and narrow in side view, 

 15-19 by 32-90/i, outer wall thin 1.5-2/x, nearly or quite smooth, 

 inner and side walls moderately thick, 3-6//,, closely spinulose 

 with short spine-like papillae interspersed with lower oval or 

 ridge-like papillae; aeciospores globoid or ellipsoid, 15-23 by 

 18-27/x, wall chestnut-brown, rather thick, about 2.5-3/x, very 

 minutely verrucose, appearing almost smooth; pores about 6, 

 scattered. 



On Crataegus Marshal Hi Egg. (C. apiifolia Michx.) Auburn, 

 Lee Co., Alabama, Nov. 20, 1897, F. S. Earle; Aldenbridge, La., 



