Aecia hypophyllous [underside of leaf], rather widely separated in oblong-annular groups 2-6 mm. across, on discolored spots, at first cylinidrical, 1-1.5 mm. high, 0.2-0.5 mm. in diameter; peridium soon becoming finely fimbriate and strongly revolute; peridial cells long and narrow, 10-14 μ x 65-85 μ, becoming curved when wet; aecio-spores angular-ellipsoid, 18-23 μ x 23-29 μ; wall chestnut-brown, 1.5-2.5 μ thick, finely verrucose; germ pores 6-8, scattered. (pg 503)