We investigated fruit set, seed set, and germination requirements of shrubby reed-mustard (Hesperidanthus suffrutescens), an endangered endemic shrub in the Uinta Basin of eastern Utah, U.S.A. To determine the degree of self-compatibility, 120 plants received four pollination treatments each for 2 y. Treatments included autogamy, geitonogamy, xenogamy, and an open control. Autogamy and geitonogamy produced substantially and significantly fewer fruits, seeds, and seeds per fruit than xenogamy, suggesting little self-compatibility. Additionally, the maternal reproductive success of outcrossed flowers was significantly greater than open control flowers suggesting pollen limitation, perhaps due to reduced pollinator abundance or activity...