520 



COMPOSITAE. 



VOL. III. 



92. MATRICARIA L. Sp. PI. 890. 1753. 



Annual or perennial, mostly erect herbs, similar to some species of the preceding genus, 

 with alternate leaves, dissected into filiform or narrowly linear segments and lobes, and 

 peduncled heads of both tubular and radiate flowers, or rays wanting in some species. Invo- 

 lucre hemispheric, its bracts appressed, imbricated in few series, the outer shorter. Recep- 

 tacle conic, elongated or hemispheric, naked. Rays, when present, white, pistillate and fertile. 

 Disk-flowers yellow, perfect, fertile, their corollas 4-5-toothed. Anthers obtuse and entire 

 at the base. Style-branches of the disk-flowers truncate, penicillate. Achenes 3~5-ribbed. 

 Pappus none, or a coroniform border. [Latin, matrix, from its medicinal virtues.] 



About 20 species, natives of the northern hemisphere and South Africa. The following are the 

 only ones known to occur in North America. Type species : Matricaria inodora L. 



Rays present, white. 



Achenes obpyramidal, strongly 3-ribbed. 



Plant tall, much branched ; bracts of the involucre green. i. M. inodora. 



Plant low, nearly simple, arctic ; bracts dark brown or black. 2. M. grandiflora.. 



Achenes nearly terete, oblong, faintly 3-s-ribbed. 3. M. Chamomilla. 



Rays none ; achenes oblong, faintly nerved. 4. M. matricarioides. 



i. Matricaria inodora L. Scentless Camo- 

 mile. Corn Mayweed. Fig. 4565. 



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



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

 1763- 



Annual; stem usually much branched, glabrous, 

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

 numerous, sessile, 2-3-pinnately dissected into fili- 

 form lobes, the rachis somewhat dilated at the 

 base; heads several or numerous, terminating the 

 branches, i'-ii' broad; bracts of the involucre 

 lanceolate-oblong, obtuse, green with brown scari- 

 ous margins ; rays 20-30, white, spreading ; recep- 

 tacle hemispheric or ovoid ; achenes obpyramidal 

 with three prominent ribs; pappus a short entire 

 or 4-toothed crown. 



In fields and waste places, Newfoundland to New 

 Jersey, Pennsylvania and Michigan. Naturalized or 

 adventive from Europe. June-Sept. 



2. Matricaria grandiflora (Hook.) Britton. 

 Arctic Camomile. Fig. 4566. 



Chrysanthemum grandiflorum Hook, in Parry's 2d Voy. 398. 

 1825. 



Pyrethrum inodorum var. nanum Hook. Fl. Bor. Am. i : 

 320. 1833. 



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



Perennial ; stem usually simple and monocephalous 

 glabrous, 4'-i2' high. Leaves sessile, or the lowest 

 short-petioled, i-2-pinnately dissected, \'-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 hemispheric when mature. 



Coast of Hudson Bay to Alaska. Reported from Lake 

 Huron. Summer. 



