960 . CARDUACEAE 



lobes; involucres 7-10 mm. broad; bracts glabrous, oval to oblong, with broad 

 scarious margins; ligules none; disk-corollas yellow, 4-lobed; receptacle conic; 

 achenes oblong, slightly angular; pappus an obscure crown. M. discoidea DC. 

 M. matricarioides (Less.) Porter. Moist and sandy places, roadsides, and waste 

 places: Alaska — Calif. — Ariz. — N.D.; adv. or nat. eastward to Newf. — N.J. — 

 N.Y., and in Eu. Plam — Suhmont. Mr-S. 



119. LEUCANTHEMUM (Tourn.) Mill. Ox-eye Daisy. 



Perennial herbs with rootstocks. Leaves alternate, dentate or entire or in 

 some exotic species pinnatifid. Heads radiate, rarely discoid, soUtary, rather 

 long-pedimcled at the ends of the stems. Involucre saucer-shaped ; bracts many, 

 rather narrow, in 2-4 series, somewhat imbricate. Receptacle flat or convex, 

 naked. Ray-flowers in a single series, pistillate and fertile; hgules usually well- 

 developed, white. Disk-corollas yellow. Anthers with ovate tips. Style of 

 the ray-flowers sUghtly exserted, with short oblong branches, that of the disk- 

 flowers included and with short branches, truncate and fimbriate at the apex. 

 Achenes all cjdindric, 10-ribbed or 10-angled. Pappus wanting. 



1. L. Leucanthemum (L.) Rydb. Stem 3-10 dm. high, glabrous; basal leaves 

 petioled, obovate or spatulate, coarsely dentate or incised; stem-leaves sessile, 

 narrowly oblanceolate to nearly hnear, dentate; involucres 12-15 mm. broad; 

 bracts lanceolate, margined by a narrow brown band and a scarious margin ; ligules 

 white, 12-15 mm. long. Chrysanthemum Leucanthemum L. L. vulgare Lam. 

 Meadows, roadsides, and pastures: Lab. — Fla. — Utah — B.C.; nat. from Eu. 

 Plain — Suhnont. My-N. 



120. TANACETUM (Tourn.) L. Tansy. 



Strongly aromatic, leafy, mostly perennial herbs, with rootstocks. Leaves 

 alternate, once to thrice pinnatifid, conspicuously punctate. Heads corymbose, 

 usually several or many, radiate, but the rays often inconspicuous and not ex- 

 ceeding the disk. Involucre hemispheric or broader; bracts in 2-3 series, usually 

 narrow, not very unequal in length; receptacle convex, naked. Ray-flowers 

 pistillate and fertile; ligules yellow, varying from erect, 3-lobed, concave and 

 scarcely exceeding the disk to spreading, flat, and well developed. Disk-flowers 

 many, hermaphrodite and fertile; corollas yellow. Style in the ray-flowers 

 shghtly exserted, in the disk-flowers included. Anthers with obtuse tips. Achenes 

 subcyhndric, those of the ray-flowers mostly 3-angled, those of the disk-flowers 

 5-angled. Pappus-squamellae united into a short crown. 



1. T. vulgare L. Stout perennial; stem 5-10 dm. high, glabrous or nearly 

 so; leaves bipinnatifid, with oblong-acute serrate divisions, glabrous or nearly 

 so; heads numerous in a corymbiform panicle; involucre 6-10 mm. broad; floweis 

 yellow; marginal flowers with short obUque 3-toothed Umbs. Roadsides and 

 waste places: N.S. — N.C. — Miss.; Calif. — Wash., escaped from cultivation; native 

 of Eurasia. Jl-S. 



121. SPHAEROMERIA Nutt. 



Low cespitose perennials, with a woody base, or small shrubs. Leaves alter- 

 nate, often crowded at the base, pinnately or pcdately divided or simple, usually 

 silvery-canescent. Heads heterogamous but apparently discoid, few, corym- 

 bose, or in subcapitate clusters or solitary. Involucre hemispheric to broadly 

 campanulate; bracts few, in 2 subequal series, usually broad; receptacle conic or 

 convex, naked. Marginal flowers (functionally ray-flowers) few, pistillate and 

 fertile, but without ligules; corollas cylindric to lance-ovoid, 3- or 4-lobed, 

 slightly if at all obhque. Disk-flowers many, hermaj)hrodite and fertile; corollas 

 with the short tube passing into the campanulate or cylindro-campanulate 

 throat. Style of the ray-flowers short-exsertcd, that of the disk included; 

 branches of the former oblong, obtuse, of the latter short, truncate and penicillate 

 at the apex. Achenes subcyhndric, tapering at the base, 5-10-ribbed. Pappus 

 wanting. 



