Matricaria. COMPOSITE. 413 



" Lake Huron, Br. Todd.'''' York Factory, Drummond ; and as far north 

 as Bear Lake, Richardson! ji. Shores and islands of the Arctic sea, 

 Richardson ! Chamisso.'" Hook. — We are not well satisfied that the Ameri- 

 can plant is the same as the European M. inodora, or that it is an annual. 



§ 2. Heads discoid, rayless: pappus none, or an obscure entire margin: 

 corolla of the disk 4-toothed, obcompressed, and more or less 2-winged. 

 — Anactidea, DC. (Lepidotheca, Nutt.) 



2. M. discoidea (DC. ! 1. c.) : branched from the base, glabrous, leafy ; 

 leaves 2-3-pinnately parted ; the lobes short, linear, acute ; heads (small) on 

 short peduncles ; scales of the involucre oval, with broad while scarious mar- 

 gins ; rays none ; pappus an obsolete coroniform margin ; receptacle acute- 

 ly conical. — M. tanacetoides, Fisch. S^' Meyer, 7tk ind. sem. St. Petersh. 

 Santolina suaveolens, Pursh ! jl. 2. p. 520 ; DC. prodr. 6. p. 37. Artemisia 

 matricarioides, Less, in Linneea, 6. p. 210. Tanacetum matricarioides. Less, 

 syn. p. 265. T.? suaveolens. Hook.! fl. Bor.-Am. 1. p. 2,21, t. 110. T. pau- 

 ciflorum, DC. prodr. 6. p. 131 ; not of Richards. Cotula matricarioides, 

 Bongard, veg. Silcha, in mem. acad. St. Petersh. I. c. p. 150. Lepidotheca 

 suaveolens, Nutt. ! in trans. Amer. phil. soc. {n. ser.) 7. p. 397. 



Western America from California! to Unalaschka! Shcha! and the ad- 

 jacent parts of Asia. Also in barren places around St. Louis, Missouri, Dr. 

 Engelmann ! perhaps introduced, as Nuttall states it was raised in a garden 

 at Philadelphia from seeds brought by Capt. Lewis. May-July. — An in- 

 conspicuous weed-like plant ; "with nearly the receptacle, involucre, and 

 achenia of M. suaveolens." The achenia of this species, and of M. Cham- 

 omilla, although appearing perfectly smooth under an ordinary lens, when 

 moistened emit from their whole surface innumerable filaments of extreme 

 tenuity, forming a kind of gelatinous mass, much as in Blennosperma, 

 p. 272. 



M. Chamomilla (Linn.), which abounds in waste grounds in Europe, and possess- 

 ing to some extent the bitter and aromatic properties of the officinal Chammomile, is 

 sometimes substituted for it, under the name of Wd I Chammomile, has been collected 

 in Texas (" Bottom land on the Brazos") by Dr. Lindheimer : doubtless introduced, 

 and perhaps very locally naturalized. 



Pyrethrum Parthenium (the Feverfeid) has escaped from gardens, and is begin- 

 ning to be naturalized in some places. 



P. serotinum, Linn., which has been in cultivation for a long period, is doubtless 

 not of North American origin. 



Chrj/santhemum ? nanum (Hook.) : stem somewhat branched, clothed with loose 

 deciduous wool ; leaves pinnatiiid ; the segments linear and entire ; heads terminal, 

 solitary ; achenia obovate-oblong, minutely papillose (receptacle naked, convex ; rays 

 8-10, entire, apparently white; scales of the involucre elliptical.) Hook'. Jl. Bor.- 

 Am.. 1. p. 320. 



North West Coast of America, Menzies. — A plant of doubtful genus, 3-5 inches 

 high ; the head about the size of a Daisy. Hook. 



Div. 3. CoTULE^: & Artemisie^:, DC. — Receptacle naked 

 (not chaffy. ) Heads discoid, homogamous or heterogamous; the flowers all 

 tubular ; those of the disk perfect, but sometimes infertile. 



154. AROMIA. Nutt. in trans. Amer. phil. soc. {n. ser.) 7. p. 395. 



Heads discoid, heterogamous ; the flowers all tubular ; the 4 or 5 marginal 

 pistillate, with the corolla obliquely truncate and 2-3-toothed ; the others 



