TIARELLA (from tiara, a Persian diadem; alluding to the shape of the capsules). ORD. Saxifrageae. A genus including five species of hardy, erect, slender, perennial herbs; one is a native of the Himalayas, and the rest are North American. Flowers white, on slender pedicels; calyx tube short, the limb five-lobed; petals five, entire; stamens ten, the filaments elongated; racemes terminal. Leaves mostly radical, long-stalked, simple or trifoliolate; stipule small, adnate with the petioles. TIARELLA cordifolia is the best-known species. It thrives in ordinary soil, and is well suited for rockwork, or for the front of the flower border. Increased by divisions. TIARELLA cordifolia (heart-shape-leaved). * False Mitrewort. fl. white; petals oblong, clawed; raceme simple; scapes 6in. to 12in. high. April. l. cordate, acutely lobed, unequally mucronate-toothed, hirsute above, pubescent beneath. Stem thick, sending out creeping stolons after flowering. North America, 1731. (B. M. 1589.) TIARELLA Menziesii (Menzies'). A synonym of Tolmica Menziesii.