Leucanthemum. composite. 393 



1. Leucanthemum vulgare, Lam. White-weed. Daisy. 



Stem erect, simple, somewhat branched ; leaves laciniately incised or pinnatifid-toolhed 

 the cauline ones sessile and somewhat clasping; the radical obovate-spatulate, petioled 

 scales of the involucre with narrow scarious rusty-brown margins. — DC. prodr. 6. p. 46 

 Torr. ^ Gr. fl. N. Am. 2. p. 412. Chrysanthemum Leucanthemum, Linn. sp. 2. p. 889 , 

 Engl. hot. t. 601 ; Pursh, fl. 2. p. 526 ; Ell. sk. 2. p. 400 ; Bigel. fl. Bost. p. 301 ; Beck, 

 hot. p. 212 ; Darlingt. fl. Cest. p. 490. 



Stem 1 - 2 feet high, erect or assurgent, smoothish. Leaves 1 - 2 inches long, smooth, 

 mostly pinnalifid-toothed towards the base ; the radical ones often orbicular-spatulate. Heads 

 1 J - 2 inches diameter. Rays 20 - 30, elliptical-oblong. Disk-flowers very numerous. 

 Achenia of the ray, as well as of the disk, without a pappus, dark purple. 



Fields, meadows and road-sides ; every where naturalized. June - August. Introduced 

 from Europe. A very pestilent weed. 



Div. 3. CoTULE^ and Artemisie.1;, DC. Receptacle naked {not chaffy). Heads discoid, homo- 

 gamous or helerogamous ; thefloioers all tubular; those of the disk perfect, but sometimes 

 infertile. 



33. TANACETUM. Linn.; DC. prodr. 6. p. 127. tansey. 



[A name altered from Alhanasia ; a, not, and thaiiatos, death; because its flowers are lasting.] 



Heads discoid, Jiomogamous, with the flowers all tubular and perfect, or heterogamous ; the 

 marginal flowers pistillate, in a single series, 3 - 4-toothed. Scales of the involucre im- 

 bricated, dry. Receptacle convex, naked. Achenia angled or ribbed, smooth, with a large 

 epigynous disk. Pappus either none or minute, membranaceous, coroniform, entire or 

 toothed, often unequal. — Herbs or sufiruticosc plants, with alternate variously dissected 

 leaves and solitary or corymbose heads. Flowers yellow. 



1. Tanacetum vulgare, Linn. Common Tansey. 



Stem herbaceous, erect, smooth ; leaves nearly smooth, bipinnately parted ; the rachis and 

 lobes incisely serrate ; corymb of numerous heads ; inner scales of the involucre scarious at 

 the apex, obtuse; pappus short, equal, 5-lobed (DC). — Engl. hot. t. 1229; Pursh, fl. 2. 

 p. 522 ; Torr. compend. p. 287 ; Beck, hot. p. 211 ; Darlingt. fl. Cest. p. 492 ; DC. prodr. 

 6. p. 128 ; Torr. Sf Gr. fl. N. Am. 2. p. 414. 



Perennial. Stem 2-4 feet high, ribbed. Leaves smoothish, dotted. Heads of flowers 

 depressed, in dense fastigiate corymbs. Corolla sprinkled with resinous dots. Pappus 

 coroniform. 



Old fields, road-sides and cultivated grounds : naturalized in many places. Introduced 

 from Europe. July - October. A well known domestic medicine. 

 [Floka.] 50 



