BULLETIN 247, U. S. DEPARTMENT OF AGRICULTURE. 



caulicolous, appearing on branches or trunks, forming le- 

 sions or fusiform swellings 2 to 30 cm. long (PL II, fig. 3); sori scat- 

 tered or somewhat confluent in small groups, rounded or irregular , 

 2 to 6 mm. long by 2 to 4 mm. wide by 1 to 2 mm. high; peridium 

 usually only slightly protruding from the bark, bladdery, subhemi- 

 spherical, rupturing irregularly along the top and sides, without con- 

 colorous processes, about 2 cells thick, outer surface minutely and 

 rather closely verrucose, inner surface also rather closely verrucose 

 but with longer tubercles; peridial cells with a radially striate mar- 

 gin, not easily torn apart, those of the inner layer often irregularly 

 compressed, walls thin, 2 to 4 /z in thickness, lumen large; cells in 

 the upper portion of the peridium ovate, 15 to 20 by 22 to 42 //, in 

 the lower portion ellipsoid to ovate, 16 to 20 by 40 to 60 /*; a3cio- 

 spores very variable in size and shape, subglobose, obovate, ellipsoid, 

 pyriform or even subclavate on some hosts, more or less acuminate 

 at the basal end, occasionally at both ends (PL I, figs. 1, 2, and 3), 

 15 to 27 by 25 to 74 /*, average for 160 seciospores 21.6 by 57.5 /i, 

 walls colorless, thicker at both ends than in the middle, 2 to 4 /* 

 thick, rather densely verrucose with small irregular tubercles which 

 in narrow ellipsoid spores are often arranged in irregular almost paral- 

 lel lines or with a ridgelike marking, which gives the surface a reticu- 

 late appearance, no smooth spot present; cell contents of the secio- 

 spores orange yellow when fresh. 



Found on Pinus contorta Loud., P. divaricata (Ait.) Du Mont du 

 Cours., P. ponderosa Laws., P. ponderosa scopulorum Sudw., P. 

 pungens Michx., and Pinus sp. 



Uredinia amphigenous or hypophyllous, 1 scattered or densely gre- 

 garious, on pallid areas, pustular, 125 to 200 /* in diameter, dehiscent 

 by a central opening or pore; peridium delicate; urediniospores 

 broadly elliptical to globoid, 16 to 21 by 19 to 25 ^, average for 10 

 spores 17.8 by 20 //, walls nearly colorless and sparsely but minutely 

 echinulate, 1.5 to 2 /* thick. 



Telial columns amphigenous or hypophyllous, 1 caulicolous, cylin- 

 drical, 80 to 115 n thick, about 1 mm. in length; teliospores oblong 

 to cylindrical, obtuse to truncate at one or both ends, 12 to 16 by 28 

 to 40 /JL, average for 10 spores 14 by 32.7 /*, walls smooth, nearly 

 colorless. 



Found on Comandra pallida A. DC., C. umbellata (L.) Nutt. 7 and 

 C. richardsiana Fernald (?). 



In the preceding description by the junior writer, the aecial char- 

 acters (Peridermium) are taken from the specimens named in Table 

 II on Pinus contorta, P. ponderosa, P. ponderosa scopulorum, and 

 P. pungens. The uredinial and telial characters (Cronartium) are 



1 Amphigenous on -Comandra pallida, hypophyllous on Comandra umbellata. 



