Puccinia arracacharum (Lindr.) Arthur 1918

Dicaeoma arracacharum (Lindr.) Arthur
Caeoma Arracacharum Lindr. Medd. Stockh. Hogsk. Bot. Inst. 4^: 1. 1901.
Puccinia Arracachae Lagerh. & I^indr.; Lindr. Medd. Stockh. Hogsk. Bot. Inst. 4": 5. 1901.
Puccinia Arracacharum Arth. Am. Jour. Bot. 5: 476, 1918.
Pycnia usualiy epiphyllous, few, in small groups 0.1-0.3 mm. in diameter, noticeable, chestnut-brown, globoid, 150-220 ju in diameter; ostiolar filaments 80-96 m long, not projecting beyond the ostiole.
1. Aecia amphigenous, in groups of 2-6 with the pycnia, round, very small, 0.1 mm. or less in diameter ; peridium wanting, the aecia bounded by a thin layer of mycelium ; aeciospores angularly ellipsoid or oblong, 18-23 by 2-^35 /i; wall colorless, 2-2.5 n thick, variably verrucose, sometimes appearing echinulate.
Uredinia hypophyllous, scattered, round, 0.2-0.5 mm. across, eariy naked, pulverulent, yellow or pale cinnamon-brown, ruptured epidermis evident; urediniospores ellipsoid or obovoid, 18-24 by 29-37 m; wall colorless or yellowish, moderately thick, 1.5-2.5 /z, closely echinulate, the pores obscure.