XANTHORHIZA (from xanthos, yellow, and rhiza, a root; alluding to the bright yellow colour of the long roots and rootstock). SYN. Zanthorhiza. ORD. Ranunculaceae. A monotypic genus. The species is a hardy, dwarf shrub or under-shrub. It thrives in common garden soil, and may be increased by suckers. XANTHORHIZA apiifolia (Apium-leaved). fl. dark purple, small, often polygamous, in slender, compound racemes, appearing before (and under) the leaves; sepals five, petaloid; petals five, small, clawed, often dilated at apex. March and April. l. pinnate, long-petiolate; leaflets three to five, ovate and lanceolate-ovate, incisely lobed and toothed from near the acute base. Stems 2ft. to 3ft. high. North America, 1766. (B. M. 1736; B. M. Pl. 9.)