Genus S6.] 



THISTLE FAMILY. 



459 



I. Matricaria inodora L. Scentless 

 Camomile. Corn Mayweed. 

 (Fig. 3992.) 



Matricaria inodora L- Fl. Suec. Ed. 2, 297. 1755. 

 Chrysanthemum inodorum L. Sp. PI. Ed. 2, 1253. 



1763. 



Annual; stem usually much branched, gla- 

 brous, or very nearly so throughout, i-2 high. 

 Leaves numerous, sessile, 2-3-pinnately dis- 

 sected into filiform lobes, the rachis somewhat 

 dilated at the base. Heads several or numerous, 

 terminating the branches, Yz'-^Yz' broad; bracts 

 of the involucre lanceolate-oblong, obtuse, 

 green with brown scarious margins; rays 20-30, 

 white, spreading; receptacle hemispheric or 

 ovoid; achenes obpyramidal with three promi- 

 nent ribs; pappus a short entire or 4-toothed 

 crown. 



In fields and waste places, Newfoundland to New 

 Jersey, and locally in the interior. Naturalized or 

 .adventive from Europe. June-Sept. 



2. Matricaria grandiflora (Hook.) Britton. 

 Arctic Camomile. (Fig. 3993-) 



Chrysanthemum grandiflorum Hook, in Parry's 2d 



Voy. 398. 1825. 

 Pyrethrum inodorum var. nanuni Hook. Fl. Bor. Am. 



1:320. 1833. 

 M. grandiflora Britton, Mem. Torr. Club, 5: 340. 1894. 



Perennial; stem usually simple and monocephal- 

 ous, glabrous, 4 / -i2 / high. Leaves sessile, or the 

 lowest short-petioled, 1-2-pinnately dissected, i / -2^ / 

 long. Head not very long-peduncled, i / -2 / broad; 

 bracts of the involucre ovate or ovate-oblong, obtuse, 

 glabrous, brown or nearly black, or with broad, 

 brown, scarious margins; rays 15-35, bright white, 

 slightly 3-5-toothed at the summit; receptacle hemi- 

 spheric when mature. 



Coast of Hudson Bay to Alaska. Reported from Lake 

 Huron. .Summer. 



3. Matricaria Chamomilla L. Wild 

 or German Camomile. (Fig. 3994.) 



Matricaria Chamomilla L- Sp. PI. 891. 1753. 



Annual, glabrous, much branched, i-2 high. 

 Leaves aromatic, finely 2-3-piunately dissec- 

 ted into numerous linear lobes; heads numer- 

 ous, 8 // -i2 // broad, slender-peduncled at the 

 ends of the branches; bracts of the involucre 

 oblong, obtuse, green, or with brownish mar- 

 gins; rays 10-20, white, spreading; receptacle 

 ovoid, becoming conic and hollow; achenes 

 nearly oblong, or somewhat obovoid, faintly 3- 

 5-ribbed; pappus none. 



In waste places and on ballast, southern New 

 York to Pennsylvania. Adventive or fugitive 

 from Europe. Called also Horse-gowan. Summer. 



