Clubmoss (Selaginella densa Rydb) provides extensive ground cover throughout the Northern Mixed Prairie of North America but little is known about how this cryptogam affects seedling emergence relative to precipitation Seedbed treatments including a control Glyphosate applied to kill clubmoss and clubmoss removal were factorially combined with ambient precipitation precipitation reduced and irrigation Graminoid and forb emergence in the seedbeds and the microsites of live clubmoss dead clubmoss bare soil litter and caespitose grasses was determined Forb emergence was greatest with clubmoss removal and irrigation About 2 6-3 6-fold more forbs emerged from bare soil microsites but clubmoss reduced forb emergence by 32-76% Litter reduced forb emergence in 2 of 3 years Graminoid emergence did not vary among seedbeds (P >= 0 780) but Irrigating increased seedling emergence Graminoid emergence was unaffected or improved in live clubmoss dead clubmoss bare soil and litter microsites In the semiarid Northern Mixed Prairie above-average precipitation combined with bare soil will favor emergence of forbs By contrast clubmoss does not limit graminoids because seedlings emerge from a range of seedbeds and microsites provided diaspores are present and precipitation is above average Emergence of graminoids and forbs is constrained primarily by precipitation in the semiarid Northern Mixed Prairie (C) 2010 Elsevier Ltd All rights reserved