Pontania with Type II 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]
Pontania with Type II galls are confined to the exiguoid willows (in California, S exigua and varieties, and S. geyeriana Andersson). These cecidia are large (9-12 mm), round, thin-walled, have a slightly wrinkled surface, and protrude through both upper and lower surfaces of the leaf. They do not fit any of Benson's categories. S. geyeriana is very pruinose (covered with a white, waxy bloom), and so is the gall. The unidentified Pontania is a robust amber and brown species. Since S. exigua is not pruinose, neither is the gall. The Pontania on it is entirely black. These 2 willows are sympatric in transmontane California (i.e., that portion of California east of the Sierra Nevada Crest) from 1200 to 2100 m, and so are the sawflies.
”- Edward L Smith: (1970) Biosystematics and morphology of Symphyta. II. Biology of gall-making nematine sawflies in the California region©