Guide to Liverworts of Oregon: Key to Genera 72
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1a plants thallose > 2b chloroplasts numerous > 62b thallus tissue complex > 70b terrestrial > 72
Riccia sorocarpa. Left: Spencer Butte, Lane Co., Oregon. DHW m1358; right: Ferris Gulch, Jackson Co., Oregon, DHW 9186.
72a Upper epidermis composed of cells which are all alike; plants repeatedly bifurcating, tending to form rosettes; lobes with sharp, dorsal, median furrow, at least at lobe tip; sex organs embedded in thallus, the capsule also remaining embedded; lacking elaters
Riccia
Conocephalum conicum, Lincoln County, Oregon.
72b Pores in upper epidermis surrounded by cells different from other epidermal cells; plants usually not forming clear rosettes but eventually sprawling with irregular branching; lobes sometimes
canaliculate but not sharply furrowed; sex organs variously placed, the archegonia and capsules usually
developing in structures elevated above surface of thallus; elaters present
(Couplet 73)