Anecdotal evidence suggested that germination and seedling growth of the federally endangered beach clustervine (Jacquemontiareclinata [Convolvulaceae]) were best in the shade, but mature plants usually occur in coastal strand areas that are open or have low vegetation. We conducted an experiment using potted seedlings grown without shade, or under low, moderate, or heavy shade enclosures. Shade did not affect shoot growth, or leaf or stem dry mass. Plants subjected to all levels of shade, however, had 40% to 70% less root dry mass and about 50% lower root-to-shoot ratios than non-shaded plants. Moreover, the roots of non-shaded plants had 2 to 4 times more soluble sugars and starch than plants grown in shade. These findings suggest that when water and nutrition are not limiting, J. reclinata seedlings are best grown without shade.