A new acridone alkaloid, 1,3,5-trihydroxy-10-methylacridone (8), and two new coumarins, trans-clausarinol (9) and khelmarin-D (11), were isolated from the root of Yalaha [several hybrid seedlings resulting from a cross of Duncan grapefruit (Citrus paradisi Macf.) x Dancy tangerine (C. tangerina Hort. ex Tanaka)], and structures were determined on the basis of spectroscopic evidence. Seventy known coumarins, acridone alkaloids and miscellaneous compounds were also characterized.