Spots dark red, resting spores globose or slightly elliptical, .07-.10mm in diameter, epispore thin and smooth, in oval host-cells, which do not project beyond the surface of the leaves. Sori yellow, about .12-.15mm in diameter, sunk in the leaves.
On leaves of Malacothrix.
Santa Cruz, California ...
When the parasite is not very abundant the leaves are turned dark red, but not distorted. When it is abundant, however, the leaves are reduced in size and become irregularly knotted and twisted. The affected cells swell to a considerable size, but are always sunk in the leaves and do not rise above the surface, so as to form galls properly speaking. The resting spores are found one or two in a cell. The sori, unlike those of S. Holwayi, completely fill the hostcell when mature.