GENUS 92. 



THISTLE FAMILY 



3. Matricaria Chamomilla L. Wild or 

 German Camomile. Fig. 4567. 



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



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

 Leaves aromatic, finely 2-3-pinnately dissected 

 into numerous linear lobes ; heads numerous, 

 8"-i2" broad, slender-peduncled at the ends of 

 the branches; bracts of the involucre oblong, 

 obtuse, green, or with brownish margins ; rays 

 10-20, white, spreading ; receptacle ovoid, be- 

 coming conic and hollow ; achcnes nearly oblong, 

 or somewhat obovoid, faintly 3-5-ribbed; pappus 



In waste places and on ballast, southern New York 

 to Pennsylvania. Adventive or fugitive from Eu- 

 rope. Horse-gowan. Summer. 



4. Matricaria matricarioides (Less.) 



Porter. Rayless Camomile. Wild 



Marigold. 4568. 



Santolina suaveolens Pursh, Fl. Am. Sept. 520. 



1814. Not M. suaveolens L. 1755. 

 Artemisia matricarioides Less. Linnaea 6: 210. 



1831. 



Matricaria discoidea DC. Prodr. 6: 50. 1837. 

 Matricaria matricarioides Porter, Mem. Torr. 



Club 5: 341. 1894. 

 M. suaveolens Buchenau, Fl. Nord. Tief. 496. 



1894. 



Annual, glabrous ; stem very leafy, at length 

 much branched, 6'-i8' high. Leaves 2-3-pin- 

 nately dissected into linear acute lobes ; heads 

 numerous, 3"-4" broad, peduncled ; bracts of 

 the involucre oval or oblong, green, with 

 broad white scarious margins, much shorter 

 than the ovoid yellow disk; rays none; recep- 

 tacle conic ; achenes oblong, slightly angular, 

 faintly nerved ; pappus an obscure crown, 

 sometimes produced into 2 coriaceous oblique 

 auricles. 



In waste places, in ballast and along railroads, 

 Missouri to Massachusetts and Maine. Adven- 

 tive from the Pacific coast. Naturalized as a 

 weed in northern Europe. May-Aug. 



93. TANACETUM [Tourn.] L. Sp. PL 843. 1753. 



Erect, strongly aromatic herbs, our species perennials, with alternate, i-3-pinnately dis- 

 sected or divided leaves, and numerous small corymbose heads of tubular flowers, or with 

 rays sometimes present and imperfectly developed. Involucre hemispheric, depressed, or cam- 

 panulate, its bracts appressed, imbricated in several series. Receptacle flat or convex, naked. 

 Marginal flowers pistillate, fertile, their corollas 2-s-toothed or lobed, sometimes produced 

 into short rays. Disk-flowers perfect, fertile, their 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 30 snecies, natives of the northern hemisphere, 

 in California. Type species: Tanacetum vulgare L. 



Glabrous, x>r nearly so ; heads numerous, 3"- 5" broad. 

 Villous-pubescent ; heads few, 6"-8" broad. 



Besides the following, another occurs 



1 . T. vulgare. 



2. T. huronense. 



