Genus S3.] 



THISTLE FAMILY. 



455 



2. Achillea Millefolium L,. Yarrow. 

 Milfoil. (Fig. 3983.) 



Achillea Millefolium L. Sp. PI. 899. 1753. 



Perennial from horizontal rootstocks; flow- 

 ering stems pubescent, or nearly glabrous, 

 simple, or corymbosely branched above, i- 

 2 high. Basal leaves, and those of the nu- 

 merous short sterile shoots, mostly petioled, 

 sometimes io / long and V z ' wide, those of the 

 stem sessile, all narrowly oblong or lanceolate 

 in outline and finely dissected into narrow 

 pinnatifid segments, tomentose, pubescent 

 or nearly glabrous; heads numerous, 2 // -3 // 

 broad, in terminal compound dense, some- 

 what convex corymbs; involucre ovoid, its 

 bracts oblong, obtusish, pubescent; rays 4-6, 

 white, or often pink or purple. 



In various situations throughout North Amer- 

 ica; in the east occurring' as a naturalized weed, 

 greener and less tomentose than the native west- 

 ern plant, which is probably specifically dis- 

 tinct. Native also of Europe and Asia. Old 

 names, Sanguinary, Thousand-leaf, Nosebleed, 

 Old Man's Pepper, Soldier's Woundwort. June-Nov. 



84. ANTHEMIS L-. Sp. PI. 893. 1753. 



Annual or perennial herbs, with pinnatifid or dissected, alternate leaves, and usually 

 large peduncled heads of both tubular and radiate flowers, terminating the branches. Invo- 

 lucre hemispheric, its bracts imbricated in several series, scarious-margined, appressed, the 

 outer shorter. Receptacle convex, conic or oblong, chaffy at least toward the summit, 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, fer- 

 tile, yellow, their corollas with 5-cleft limbs. Anthers obtuse and entire at the base. Style- 

 branches of the disk-flowers truncate. Achenes oblong, angled, ribbed or striate. Pappus 

 none, or a short coroniform border. [Greek name of Camomile.] 



About 60 species, natives of Europe, Asia and Africa. 



Rays white. 



Rays neutral; plant glabrous, or nearly so, fetid. 1. A. Cotula. 



Rays pistillate; plants pubescent. 



Annual; chaff of the receptacle acute. 

 Perennial; chaff of the receptacle obtuse. 

 Rays yellow; plant pubescent, or tomentose. 



A. arvensis. 

 A. nobilis. 

 A. tinctoria. 



Mayweed. 

 Dillweed. 



1753- 



1837. 



1. Anthemis Cotula L,. 

 Dog's, or Fetid Camomile. 

 (Fig. 3984.) 



Anthemis Cotula L. Sp. PI. 894. 

 Manila Cotula DC. Prodr. 6: 13. 



Annual, glabrous, or sometimes pubescent 

 above, glandular and with a fetid odor and 

 acrid taste, much branched, i-2 high. 

 Leaves mostly sessile, i / -2 / long, finely 1-3- 

 pinnately dissected into narrow, or almost 

 filiform, acute lobes; heads commonly nu- 

 merous, about 1/ broad; bracts of the invo- 

 lucre oblong, obtuse or obtusish, usually 

 somewhat tomentose; rays 10-18, white, at 

 length reflexed, neutral, or rarely with 

 abortive pistils, mostly 3-toothed; receptacle 

 convex, becoming oblong, its chaff bristly, 

 subtending the central flowers; achenes 10- 

 ribbed, rugose or glandular-tuberculate; pap- 

 pus none. 



In fields, waste places and along roadsides, 

 all over North America except the extreme 

 north. Naturalized from Europe, and widely 

 distributed as a weed in Asia, Africa and Aus- 



tralasia. Other names are Mather, Dog-fennel, Dog-finkle, Morgan. June-Nov. 



