Pontania with Type IV galls [Smith does not name or describe a species and is ambiguous about whether he considers these host varieties or distinct species on each host.]

[A cross sectional drawing appears in Figure 4, on page 5 of the pdf. Two photos appear on page 7, Figure 6.]

Type IV is on the S. lasiolepis group, and is a small (5 mm) thin-walled variety, probably equivalent to part of Benson's P. viminalis (L.) group. The gall hangs from the under surface of the leaf midrib, and is smooth and glossy (Fig. 6 A). The gall may be conical or ovoid on the long axis. The Pontania of this group making galls on S. lemmonii and relatives and on S. rigida [cordata?] tend toward having spherical cecidia, while those on S. scouleriana Barratt are usually conical (Fig. 6 B). All are montane, although the one on S. rigida ranges throughout the Great Basin.