10 16 FLORA. ^ 



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. 



Rays present, white. 



Achenes obpyramida!, 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 3-5-ribbed. 3. M. Chamomilla. 



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



1. Matricaria inodora L. SCENTLESS CAMOMILE. CORN MAYWEED. (I. F. f. 

 3992.) Annual; stem glabrous, or very nearly so throughout. 3-6 dm. high. 

 Leaves numerous, sessile, 2-3-pinnately dissected into filiform lobes, the rachis 

 somewhat dilated at the base. Heads several or numerous, terminating the 

 branches, 1.5-4 cm. broad; bracts of the involucre lanceolate-oblong, obtuse, green 

 with brown scarious margins; receptacle hemispheric or ovoid; pappus a short 

 entire or 4-toothed crown. In fields and waste places, Newf. to N. J., and locally 

 in the interior. Nat. or adventive from Europe. June-Sept. 



2. Matricaria grandiflora (Hook.) Britton. ARCTIC CAMOMILE. (I. F. f. 

 3993.) Perennial; stem usually simple and monocephalous, glabrous, 1-3 dm. 

 high. Leaves sessile, or the lowest short-petioled, i-2-pinnately dissected, 3-7 cm. 

 long. Head not very long-peduncled, 3-5 cm. broad; bracts of the involucre ovate 

 or ovate-oblong, obtuse, glabrous, brown or nearly black, or with broad, brown, 

 scarious margins; receptacle hemispheric when mature. Coast of Hudson Bay to 

 Alaska. Reported from Lake Huron. Summer. 



3. Matricaria Chamomilla L. WILD OR GERMAN CAMOMILE. (I. F. f. 

 3994.) Annual, glabrous, much branched, 3-6 dm. high. Leaves aromatic, finely 

 2-3-pinnately dissected into numerous linear lobes; heads numerous, 16-25 mm - 

 broad, slender-peduncled at the ends of the branches; bracts of the involucre 

 oblong, obtuse, green, or with brownish margins; receptacle ovoid, becoming conic 

 and hollow ; pappus none. In waste places and on ballast, southern N. Y. to Penn. 

 Adventive or fugitive from Europe. Summer. 



4. Matricaria matricarioides (Less.) Porter. RAYLESS CAMOMILE. (I. F. 

 f- 3995-) Annual, glabrous; stem very leafy, at length much branched, 15-45 

 cm. high. Leaves 2-3-pinnately dissected into linear acute lobes; heads numer- 

 ous, 68 mm. broad, peduncled ; bracts of the involucre oval or oblong, green with 

 broad white scarious margins, much shorter than the ovoid yellow disk ; receptacle 

 conic; pappus an obscure crown, sometimes produced into 2 coriaceous oblique 

 auricles. In waste places, in ballast and along railroads, Mont, to Mo., Me. and 

 Mass. Adventive from the Pacific coast. May -Aug. 



88. TANACETUM L. 



Erect, strongly aromatic herbs, our species perennials, with alternate, 1-3 -pin- 

 nately dissected or divided leaves, and numerous small corymbose heads of tubular 

 flowers, or with rays sometimes present and imperfectly developed. Involucre 

 hemispheric, depressed, or campanulate, its bracts appressed, imbricated in several 

 series. Receptacle flat or convex, naked. Marginal flowers pistillate, fertile, 

 their corollas 2-5-toothed or lobed, sometimes produced into short rays. Disk-flowers 

 perfect, fertile, the corollas 5 -toothed. Anthers obtuse and entire at the base, their 

 tips broad. Style-branches truncate and penicillate at the summit. Achenes 

 5 -angled or 5 -ribbed, truncate or obtuse. Pappus none, or a short crown. [From 

 tanasie, old French for tansy; Greek, athanasia, immortality.] About 35 species, 

 natives of the northern hemisphere. Besides the following, 6 others occur in western 

 and northwestern N. Am. 



Glabrous, or nearly so; heads numerous, 6-10 mm. broad. i. T. vulgar e. 



Villous-pubescent; heads few, 12-16 mm. broad. 2. T. Huronense. 



I. Tanacetum vulgare L. TANSY. (I. F. f. 3996.) Stem stout, usually 

 simple up to the inflorescence, 4-9 dm. high. Leaves pinnately divided into linear- 

 oblong, pinnatifid or incised segments, the lobes acute, usually serrate; lower seg- 

 ments of the leavesoftens mailer than the others; basal leaves often 3 dm. long; heads 



