United States, Colorado, Boulder, Mouth of South S. Vrain Canyon. Hall Ranch Open Space, S W of Lyons, desert-steppe, sandstone/conglomerate rim rock of Lyons Formation, S-W-facing gentle slope; just north of trail-head
Leaves broadly deltoid-ovate; leaf cells smooth, the median and marginal cells quadrate, thick-walled, apical cells narrow, the lumen almost excluded; costal filaments at leaf base elongate, with thin-walled rectangular cells, lacking papillae; filaments becoming very dense and much shorter at mid-leaf and distally, the papillae 2-several, solid.