XANTHOSIA (from xanthos, yellow; alluding to the yellow down with which some of the species are covered). SYN. Leucoloena. ORD. Umbelliferae. A genus comprising seventeen species of greenhouse herbs or small shrubs, diffuse or decumbent at the base, or erect, often clothed with long, soft hairs, mixed with a stellate tomentum, natives of Australia. Calyx lobes peltate, cordate, or not attached by the whole of the base; petals with an induplicate point and reduplicate margins; umbels usually compound, the partial ones with two or three bracts, and several almost sessile flowers, the general one of three or four rays, and as many bracts, but sometimes the whole umbel reduced to very few, or to a single flower. Leaves toothed, lobed, or ternately divided. The two species introduced require similar treatment to Trachymene. XANTHOSIA hirsuta (hairy). A synonym of XANTHOSIA pilosa. XANTHOSIA montana (mountain-loving). A synonym of XANTHOSIA pilosa. XANTHOSIA pilosa (pilose), fl. white; peduncles usually two at the nodes, each usually with two flowers, more rarely three or only one, with two or three short, narrow bracts forming a general involucre at the base of the short pedicels or rays. June. l. coarsely sinuate-toothed, three or five-lobed or rarely three-parted, the central lobe always longer than the lateral ones, rarely exceeding 1in. in length. h. 1ft. to 2ft. 1826. An erect, or more frequently diffuse or procumbent shrub. SYNS. XANTHOSIA hirsuta, XANTHOSIA montana. XANTHOSIA rotundifolia (round-leaved).* fl. white, rather numerous, on very short pedicels; peduncles long, each bearing a rather large, compound umbel; rays usually four, with a sessile umbellule in the centre: involucral bracts petal-like. June. l. shortly petiolate, nearly orbicular, irregularly and acutely toothed, 3/4in. in diameter, glabrous or woolly beneath, especially when young. Stems erect, 1ft. to 2ft. high, often woody at base. 1836. (B. M. 3582.)