Dichotomous table for gallers on Swertia perennis
by Hans Roskam
1a Aecia spaciously arranged, on underside of leaf blade on thickened, arched, rotund yellowish or brownish cushions or on oblong-oval, weak bulges on petioles and stems. Puccinia swertiae
1b Rotund-oval or flat spindle-shaped, one-chambered galls, up to 6 mm long; usually on petiole, also on leaf blade, on base of midrib as well as on stem base. Containing a single larva. Smicronyx swertiae