Xanthocephalum
(from xanthos, yellow, and cephale, a head; alluding to the yellow flower-heads). SYN. Xanthocoma. ORD. Compositae. A genus consisting of eight species of greenhouse or hardy herbs or sub-shrubs; one is found in Ecuador, and the rest are Mexican. Flower-heads wholly yellow, rather large or mediocre, solitary or loosely corymbose at the tips of the branches, heterogamous; involucre hemispherical or broadly campanulate, the imbricated bracts in several series; receptacle flat, foveolate; ray florets ligulate, spreading, nearly entire; disk florets five-cleft at apex; achenes glabrous. Leaves alternate, narrow, entire or toothed. Only two species call for mention here. Both thrive in any fairly good soil. X. centauroides may be increased by cuttings, and X. gymnospermoides by seeds.
X. centauroides (Centaurea-like). fl.-heads yellow, solitary; involucre clammy; outer scales spreading. July to September. l. sessile, thickish, linear, pinnatifidly toothed, wrinkled, glabrous. h. 1 1/2ft. Mexico, 1826. Greenhouse sub-shrub. SYN. Grindelia coronopifolia.
X. gymnospermoides (Gymnosperma-like).* fl.-heads orange yellow, about 1in. in diameter, corymbose. September. l. 3in. to 6in. long, lanceolate, linear, and small above, the lower ones sub-spathulate and serrated towards the point, the rest entire. h. 2ft. to 4ft. New Mexico, 1859. Hardy annual. See Fig. 230. SYN. Gutierrezia gymnospermoides (B. M. 5155).
