Arthur and Kern : North American Peridermium 123 
1026a; Underwood , Toccoa, April 19, 20, and 21, the last in 
Seym. & Earle, Econ. Fungi 224) ; Mississippi {Arthur & 
Stretch)’, Texas {Hedgcock, Forest Path. no. 7 08 ). 
Type collected in South Carolina on Pinus palustris. 
Distribution: From central North Carolina to Florida and 
westward to central Texas. The telial stage on V ernonia is com- 
mon and abundant from the Gulf of Mexico to Massachusetts, 
Indiana and Kansas, considerably further northward than the 
aecial stage has been seen. 
Since the previous paper several cultures have been made 
which show the genetic relation between this species and Coleo- 
sporium Vernoniae. The first cultures were made by the senior 
writer in the spring of 1910 (see preceding table) with Perider- 
niium specimens sent from Florida ; supplementing cultures were 
made the following season with material collected in Mississippi 
(see Mycologia 4: 57. 1912); and still further cultures with 
Florida material were made in 1913. The range of the species 
has been extended northward from South Carolina into North 
Carolina and southwestward from Mississippi into Texas. 
There are several other species of Coleosporium common in 
this range and some of them have been suspected of belonging to 
aecial forms very much like Per. carneum but no positive cul- 
tures have ever been made proving such relationships. It may be 
possible, however, that some of the specimens here listed may be 
shown later to belong elsewhere. There is a considerable variation 
in the size and thickness of walls of the spores in these specimens 
but since in the experimental work both extremes have been cul- 
tured on V ernonia the present disposition seems the only one at 
present possible. 
Key to the Caulicolous Species of Periderium on Pinus, all being the 
Aecial Stage of Species of Cronartium 
Branch or stem not noticeably swollen, peridia more 
or less cylindrical, not confluent. 12. P. filamentosum. 
Branch or stem with slight fusiform enlargement, 
peridia subhemispherical, rounded or irregular, 
sometimes confluent. 
Spores pyriform, finely and closely verrucose. 13. P. pyriforme. 
Spores ellipsoid or obovate. 
Spores with wall 1.5-2.5,14 thick, moderately 
verrucose with uniform papillae. 
14. P. Strobi. 
