COMPOSITE. (COMPOSITE FAMILY.) 199 



63. MATRICARIA, 1 Tonrn., L. 



Herbs, with finely once or thrice dissected leaves, and pedunculate heads, 

 the rays white (or wanting) and the disk-flowers yellow. 



1. M. discoidea, DC. Annual, somewhat aromatic, glabrous, a span to 

 a foot high, very leafy : leaves 2 to 3-pinnately dissected into short and narrow 

 linear lobes : heads all short-peduncled : bracts of the involucre broadly oval, 

 white-scarious with greenish centre, hardly half the length of the well-devel- 

 oped greenish-yellow ovoid disk : akenes oblong, somewhat angled, with an 

 obscure coroniform margin at summit, this occasionally produced into one or 

 two conspicuous oblique auricles of coriaceous texture. — From W. California 

 to Montana and far northward; becoming naturalized in the Atlantic States. 



64. TANACETUM, Tourn. Tansy. 



Strong-scented, alternate-leaved, yellow-flowered perennials. Ours are low, 

 with stems rather slender and naked above, bearing rather small (2 lines 

 broad) globular heads, and leaves simply or pedately 3 to 5-cleft. 



1 . T. Nuttallii, Torr. & Gray. Silvery-canescent, loosely cespitose, a span 

 high : leaves short, mostly broad-cuneate with tapering base, obtusely 3 to 5- 

 lobed at the broad summit ; those of the flowering stems usually oblong or 

 linear and entire : heads few, somewhat paniculate or loosely clustered, some of 

 them slender-pedunculate: involucre very scarious. — M. ii. 415. Mountains 

 of N. Wyoming. 



2. T. capitatlim, Torr. & Gray. Silvery-canescent, densely cespitose, a 

 span high : leaves simply or pedately 3 to 5-parted into linear lobes, or some 

 of them only 3-cleft at summit : flowering stems scapiform or 2 to 4-leaved : 

 heads 10 or more, sessile in a globose glomerule. — Loc. cit. Mountains of 

 N. Wyoming. 



65. ARTEMISIA, Tonrn., L. Wormwood. Sage-brush. 



Herbs and low shrubs, bitter-aromatic; with alternate leaves and small 

 paniculate heads, commonly nodding ; the flowers yellow or whitish, usually 

 sprinkled with resinous globules. 



§ 1. Heads heterogamous ; the dish-flowers hermaphrodite but sterile, their ovary 



abortive, and style mostly entire : receptacle not hairy. — ■ Dracunculus. 

 * Akenes and flowers beset with long cobwebby and crisped hairs : spinescent 



undershrub. 

 1. A. spineseens, Eaton. Stout and densely branched, rigid, 4 to 18 

 inches high, villous-tomentose : leaves small, pedately 5-parted and the divis- 



> The following species of the Old-World genus ChrystmtTimium has become extensively 

 naturalized, its broad heads and conspicuous white rays making it very prominent It 

 may be characterized as follows : — 



C. Leucanthemum, L. Glabrous, a foot or two high, simple or sparingly branched : eau- 

 line leaves spatulate, and the upper gradually narrower, becoming small and linear, pinnately 

 dentate or incised, partly clasping at base * radical broader, petioled : head broad and flat : 

 rays inch long: pappus none. — Known as "Ox-eye Daisy" or " Whiteweed." Lewxmthe 

 mvm vulgare, Lam. 



