Aecidium houstoniata Schwein. 1832

Nigredo houstoniata (Schw.) J. Sheldon, Torreya 9 : 55. 1909
Caeoma {Aecidium) houstoniaium Schw. Trans. Am. Phil. Soc. II. 4: 293. 1832. Aecidium, {Caeoma) houstoniaium Schw. Trans. Am. Phil. Soc. II. 4: 309, 1832. lAecidium cylindricum Ellis & Ev. Bull. Torrey Club 22 : 61. 1895. Uromyces Murrillii Ricker, Mycologia 1 : 237, hyponym. 1909. Uromyces housioniatus J. Sheldon, Torreya 9 : €s. 1909.
0. Pycnia hypophyllous, sometimes occupying the whole under surface of a leaf, numerous, not conspicuous, pale-yellow becoming reddish-brown, globoid or slightly ■depressed-globose, 80-100 /x in diameter, 65-80 m bigh ; ostiolar filaments 45-65 /i long.
1. Aecia hypophyllous, loosely scattered, often occupying the whole under surface of a leaf, short, cupulate, 0.2-0.4 mm. in diameter ; peridium colorless, the margin rather finely erose ; peridial cells rhomboidal, 19-26 /t long, the outer wall rather thick, 4-6 ju, transversely .striate, the inner wall slightly thinner, 3-4/t, moderately verrucose ; aeciospores globoid, 13-18 by 16-19 ju; wall colorless, thin, Iju, finely verrucose. pRT 3, 1912] ae;cidiace;ae; 243
On Rtjbiaceae :
tHoustonia angustifolia Michx., Kansas, Texas.
Housioma caerulea I.., Connecticut, Delaware, Massachusetts, Missouri, Pennsylvania. West Virginia. i j }
"? Hoiistonia minima Beck, Texas.
} Houstonia purpurea I,., West Virginia.
Uredinia atnphigenous, arranged in small groups, oblong or linear, 0.3-0.8 mm long, early naked, somewhat pulverulent, very pale cinnamon-brown, ruptured epidermis noticeable; urediniospores broadly ellipsoid, 16-19 by 23-26 m ; wall golden-brown, 1.5-2 m thick, sharply and strongly echinulate, the pores 3, rarely 4, equatorial.