564 COMPOSITAE (COMPOSITE FAMILY) 



linear, at length with involute margins: pappus a crown of 4 or 5 mostly con- 

 nate scales, and not rarely 1 or 2 slender usually short awns. Dry ground; 

 Colorado and Arizona to Texas. 



80. ANTHEMIS L. MAYWEED. DOG FENNEL 



Annual or perennial herbs, with pinnatifid or dissected alternate leaves 

 and peduncled heads terminating the branches. Involucre hemispheric, the 

 bracts imbricated in several series, scarious-margined, appressed, the outer 

 shorter. Receptacle convex, conic or oblong, chaffy at least toward the sum- 

 mit, the chaff subtending -the disk-flowers. Ray-flowers pistillate and fertile, 

 or neutral, the tube terete or 2- winged, the ray white or yellow, entire or 

 2-3-toothed; disk-flowers perfect, fertile, yellow, the corollas with 5-cleft 

 limbs. Achenes oblong, angled, ribbed or striate. Pappus none, or a short 

 coroniform border. 



1. Anthemis Cotula L. Sp. PI. 894. 1753. Stems rather low; herbage un- 

 pleasantly strong-scented: leaves finely 3-pinnately dissected: receptacle 

 conical: rays mostly white, neutral or abortive: achenes 10-ribbed, rugose 

 or tuberculate. An excessively common weed eastward, now not infrequent 

 in waste ground in our range. 



81. ACHILLEA L. YARROW. MILFOIL 



Ours an erect strongly scented perennial herb with finely dissected alternate 

 leaves. Heads radiate, cymose at the ends of the stem and branches. Ray- 

 flowers few, pistillate, fertile. Involucral bracts appressed, imbricated in 

 few series, the outer shorter. Receptacle nearly flat, the chaff membranous 

 and subtending fertile disk-flowers. Achenes linear or oblong to obovate, 

 obcompressed. Pappus none. 



1. Achillea millefolium L. Sp. PI. 899. 1753. From villous-lanate to gla- 

 brate; stems simple, 2-6 dm. high: leaves elongated and narrow in outline, 

 sessile, bipinnately dissected into numerous small and linear to setaceous- 

 subulate divisions: heads numerous, crowded in a fastigiate cyme; involucre 

 oblong; the bracts pale or sometimes fuscous-margined, or even wholly brown- 

 ish: rays 4-5, about the length of the involucre, white, occasionally rose- 

 color. A. lanulos.a Nutt. and A. alpicola Rydb. are merely forms of a some- 

 what variable species, though there is more homogeneity in this species than 

 in many which no one has yet thought to disintegrate. Common throughout 

 the northern hemisphere. 



82. MATRICARIA L. 



Ours glabrous annuals with alternate leaves pinnately dissected into narrowly 

 linear segments. Heads solitary or somewhat cymose, with many greenish- 

 yellow or white flowers. Receptacle mostly slender-conical, naked. Bracts 

 of the involucre imbricated in few series, the outer ones a little shorter than 

 the inner, persistent, scarious-margined. Corollas tubular and without limb 

 in our species. Pappus reduced to a coroniform border, or none. Achenes 

 glabrous, irregularly nerved. 



1. Matricaria matricarioides (Less.) Porter, Mem. Torr. Club 5: 341. 

 1894. Annual, somewhat aromatic, glabrous, 1-2 dm. high, very leafy: 

 leaves 2-3-pinmitoly dissected into short and narrow linear lobes: heads all 

 short-ped uncled; bracts of the involucre broadly oval, white-scarious with 

 greenish center, hardly half the length of the well-developed greenish-yellow 

 ovoid disk: achenes oblong, somewhat angled, with an obscure coroniform mar- 

 gin at summit, which is occasionally produced into 1 or 2 conspicuous oblique 

 auricles of coriaceous texture. M. discoidea. California and far northward 

 and east to Wyoming and Montana; becoming naturalized farther eastward. 





