Guide to Hornworts of Oregon: Key to Phaeoceros 3
Hornworts 1b stalked ventral tubers absent > Hornworts 2b spores yellow > Phaeoceros 1b spores not brown > Phaeoceros 2b sporophytes less than 2cm > Phaeoceros 3
Phaeoceros hallii, distal surface of spore. Coyote Prairie, Lane County, Oregon. DHW m2691.
3a Spores with coarse warts (verrucae) or bumps on distal surface; thallus with apical and marginal, sometimes stalked, tubers.
Phaeoceros hallii
Left: distal aspect; right: proximal aspect. Coyote Prairie, Lane County, Oregon. DHW m2691a.
3b Spores finely echinate or papillose on distal surface; thallus lacking tubers.
Phaeoceros oreganus