418 ' COMPOSITE. Taraxacum 



1. Taraxacum Dens-leonis, Desf. Common Dandelion 



Plant at length smooth ; leaves equally and acutely runcinate, the lobes toothed anteriorly 

 exterior scales of the involucre reflexed ; achenia muricate at the summit. — DC. prodr. 7 

 p. 145; Torr. <^ Gr. fl. N. Am. 2. p. 494. Leontodon Taraxacum, Linn.; Engl, hot 

 t. 510 ; Pursh,fl. 2. p. 497 ; Ell. sk. 2. p. 250 ; Bigel.fl. Bost. p. 286 ; Beck, hot. p. 168 ; 

 Darlingt. fl. Cest. p. 443. 



Root thick, descending. Leaves all radical. Scapes often several from one root. Inner 

 scales of the involucre at first appressed, at length reflexed. Beak of the achenia long and 

 very slender, forming a stipe to the diverging pappus. 



Pastures, road-sides, etc. ; every where very common. Introduced from Europe. April - 

 November. The Dandelion is sometimes used as a salad or potherb, and is also a popular 

 diuretic. An extract of the plant is sold by the Shakers. 



52. LACTUCA. Tourn. ; DC. prodr. 7. p. 135. LETTUCE. 



[ From the Latin, lac, milk ; the plant affording a milky juice.] 



Heads fevr- or several-flowered. Involucre cylindrical ; the scales imbricated in 2 - 4 series ; 

 the exterior shorter. Receptacle naked. Achenia obcompressed, flat, wingless, abruptly 

 produced into a filiform beak. Pappus of copious very soft and white capillary bristles. — 

 Caulescent herbs, with entire or pinnatifid leaves and paniculate heads. 



1. Lactuca elongata, Muhl. Wild Lettuce. Fire-weed. 



Stem tall, paniculate at the summit ; leaves partly clasping, pale underneath, the upper 

 usually lanceolate and entire, the lower runcinate-pinnatifid ; heads in an elongated leafless 

 panicle ; achenia oval, longer than the beak. — Torr. df Gr. fl. N. Am. 2. p. 496. 



var. 1 . longifolia : smooth or slightly hairy ; upper leaves lanceolate and often entire ; the 

 lower runcinate-pinnatifid, with the lobes entire or repand-toothed , terminal lobe elongated ; 

 flowers mostly yellow. — Torr. ^ Gr. I. c. L. longifolia, MicJix. fl. 2. p. 85. L. elongata, 

 Muhl. in Willd. sp. 3. p. 1523 ; Pursh, fl. 2. p. 500 ; Ell. sk. 2. p. 252 ; Bigel. fl. Bast, 

 p. 287 ; Hook. fl. Bor.-Am. I. p. 296 ; Beck, hot. p. 169 ; Darlingt. fl. Cest. p. 443 ; DC. 

 prodr. 7. p. 137. Galathenium elongatum, Nutt. in trans. Amer. phil. soc. (n. ser.) 7. p. 443. 



var. 2. integrifolia : smooth ; leaves all or nearly all undivided, lanceolate, acute or acumi- 

 nate, entire or repand-denticulate , the lowest sometimes pinnatifid ; flowers often tinged with 

 purple. — Torr. <^ Gr. I. c. L. integrifolia, Bigel.fl. Bost. p. 287 ; Beck, hot. p. 169 ; DC. 

 prodr. 7. p. 137, not of Nutt. L. sagitlifolia, Ell. sk. 2. p. 253 ; DC. I. c. Galathenium 

 integrifolium {and salicifolium, partly), Nutt. I. c. 



var. 3. sunguinea : leaves all or nearly all runcinate, mostly hairy (as well as the stem), 

 particularly on the midrib underneath , the terminal lobe not prolonged ; flowers usually more 

 or less tinged with purple or red. — Torr. ^ Gr. I. c. L. hirsuta, Muhl. cat. p. 72 ; Nutt. 

 gen. 2. p. 124 ; Beck, hot. p. 169. L. sanguinea, Bigel. I. c. ; DC. I. c. Galathenium 

 sanguineum, Nutt. trans. Am. phil. soc. I. c. 



