Guide to Liverworts of Oregon: Key to Genera 62
1a plants thallose > 2b chloroplasts numerous > 62
Aneura pinguis, Linn Co., Oregon. DHW m1284.
62a Thallus tissue homogeneous internally; composed solely of thin-walled, translucent cells, lacking air chambers; all rhizoids with smooth internal walls; lacking ventral scales (except Blasia)
Left:Riccia sorocarpa, Spencer Butte, Lane Co., Oregon. DHW m1492. Right: Pressia quadrata, Thallus cross section (lightly stained with toluidine blue). - North Cascades National Park, WA. M. Hutten.
62b Thallus tissue heterogeneous, stratified internally; composed of different cell types, usually with a distinct epidermis and internal air chambers; rhizoids dimorphic, smooth-walled ones mingled with those having internal peg-like thickenings; almost always with ventral scales
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Copyright 2006 Northwest Botanical Institute