Sphacelotheca hydropiperis (Schumach.) de Bary 1884

Foodplant / pathogen
sorus of Sphacelotheca hydropiperis infects and damages live ovary of Persicaria hydropiper
Remarks: season: 9-10
Other: major host/prey

Foodplant / pathogen
sorus of Sphacelotheca hydropiperis infects and damages live ovary of Fallopia convolvulus
Remarks: season: 8-9

Foodplant / pathogen
sorus of Sphacelotheca hydropiperis infects and damages live ovary of Persicaria lapathifolia
Remarks: season: 8-9

Foodplant / pathogen
sorus of Sphacelotheca hydropiperis infects and damages live ovary of Persicaria maculosa
Remarks: season: 8-9

Foodplant / pathogen
sorus of Sphacelotheca hydropiperis infects and damages live ovary of Persicaria laxiflora
Remarks: season: 8-9

Sphacelotheca hydropiperis (Schum.) DeBary, Verg
Morph. Biol. Pike 187. 1884.
Uredo Hydropiperis Schum. Enum. PI. Saell. 2 : 234. 1803. UsHlago Candolld Tvil. Ann. Sci. Nat. III. 7: 93. 1847. Ustilago Hydropiperis Schrot. Beitr. Biol. Pfl. 2 : 355. 1877.
Sori in ovaries, forming oblong or ovate bodies about 3-5 mm. in length, protected by floral envelopes at base, with false membrane dehiscing at apex, revealing purple-black spore-mass and ijiore or less evident columella ; sterile cells besides forming membrane also constituting part of the columella, spore-like (often probably immature spores) , hyaline or occasionally violettin ted, easily separatiiig into individual cells, chiefly subspherical, 6-17 ^ ; spores pxirplish, broadly oblong or ovate but chiefly subspherical, minutely but abundantly verruculose, mostly 10-17 ii in length.
On Polygonaceae :
Persicaria Hydropiper {Polygonurn Hydropiper) , Nebraska, Rhode Island.

Sphacelotheca borealis (Clinton) Schcilcnb. Ann. Myc. S: 386. 1907 Sphacelotheca Ilydropipcrii var. borealis Clinton, I'roc. Boston Nal Ilisi 31: 395 1904. Sori in the ovaries, forming oblong or ovate bodies, 3-4 mm. in length, protected by floral envelopes at base, with false membrane dehiscing at apex, revealing a dark-purple spore-mass and a well-developed robust columella; sterile cells hyaline or slightly tinted, subspheric, thickwalled, chiefly slightly larger than the spores; spores violet-purple, ovoid to spheric or occasionally more irregular, often apparently smooth but really minutely granular, chiefly 9-11 ;i in length.
On Polygonaceae :
Bistorta bistortoides (Polygonum bislcrtoides) , Colorado, Washington, Wyoming.
Persicaria {Polygonum) sp., California, Oregon; Nova Scotia. T'VTE locality: Mt. Rainier, Washington, on Polygonum bistortoides. Distribution: Washington and California to Colorado; Nova Scotia; also in Switzerland.