Etym.: dedicated to the German botanist who lived most of his life in Uruguay, Dr. Guillermo Herter.
Spore-sac relatively small, up to 6 mm diam, easily separated from the stem. Exoperidium apparently hyphal, with mycelial threads agglutinated with soil particles. Endoperidium not completely smooth, light ferrugineous. Mouth fibrillose, large for the size of the peridium, felty, with a dentate peristome as in a bryophyte capsule. Socket appressed, shallow, with a dentate membrane. Gleba ferrugineous to ochraceous. Stem up to 10 x 1.2 mm, light brown to dark, slightly rugose-fibrose, straight, ending basally in a small mycelial bulb.
Spores subglobose, subsmooth under L.M., appearing asperulate under a high-power immersion lens, 4-4.8 Âµm diam, episporium thick, apiculate, with a small eccentric vacuole, light yellowish brown. Under SEM the ornamentation appears formed by blunt, appressed verrucae. Capillitium branched and septate, threads thick-walled, lumen almost solid, hardly at all swollen at the scarce, uncoloured septa; 2.4-6 Âµm diam.
Habitat: in dry sites with herbaceous vegetation in sandy soils.
Distribution: South America: Argentina, Bolivia and Uruguay. North America: SE and SW United States.
Lectotype (selected): no collection indicated as a holotype was found, so the following is considered the lectotype: Uruguay: Cerro de Montevideo, leg. Herter nÂ° 2148 (FH!).