WOOTON AND STANDLEY—FLORA OF NEW MEXICO. 623 
TYPE LocaLity: ‘On the banks of the Missouri.”’ 
RanaeE: British America to Michigan, Kansas, and New Mexico. 
New Mexico: Farmington; Tunitcha Mountains; Dulce; Pescado Spring; Johnsons 
Mesa; Pecos; Perico Creek; Santa Fe; Silver City; Mangas Springs; Mogollon Moun- 
tains; Mesilla Valley; White and Sacramento mountains. Open slopes and in waste 
ground, in the Upper Sonoran and Transition zones. 
3. Lactuca ludoviciana (Nutt.) DC. Prodr. 7: 141. 1838. 
Sonchus ludovicianus Nutt. Gen. Pl. 2: 25. 1818. 
Type Locautry: ‘In humid places, in the open plains, and Fort Mandan on the 
Missouri.”’ 
Range: Montana and Minnesota to New Mexico and Texas. 
New Mexico: Farmington (Wooton 2592), River valleys, in the Upper Sonoran 
Zone. 
4, Lactuca canadensis L. Sp. P1.°796. 1753. 
Tyrer Locauity: ‘Habitat in Canada,”’ 
RanGE: British America to New Mexico and Florida, 
New Mexico: Tunitcha Mountains; Gallinas Canyon; Sandia Mountains; Mimbres 
River; Ruidoso Creek. Upper Sonoran and Transition zones. 
5. Lactuca graminifolia Michx. Fl. Bor. Amer. 2: 85. 1803. 
Type Locauiry: “‘In Carolina inferiore.”’ 
Rance: Colorado and Arizona to North Carolina and Florida, 
New Mexico: Winsors Ranch; Las Vegas; South Percha Creek; Middle Fork of the 
Gila; Parkers Well; Cloudcroft; Tularosa Creek; Ruidoso Creek. Open slopes and 
meadows, in the Upper Sonoran and Transition zones, 
8. SONCHUS L. Sow TnaistLe. 
Succulent annuals or biennials with alternate, auriculate-clasping, dentate or 
pinnatifid, prickly leaves, and corymbs of medium-sized heads of yellow flowers; 
involucre ovoid or campanulate, becoming thickened at the base, the bracts im- 
bricated in several series, the outer successively smaller; receptacle flat, naked; 
achenes oval, flattened, ribbed, truncate; pappus of soft smooth capillary bristles. 
KEY TO THE SPECIES. 
Heads 25 mm, high; involucres glandular-pubescent...........------ 3. 8. arvensis. 
Heads about 15 mm. high; involucres not glandular-pubescent. 
Auricles of leaves acute; achenes not transversely wrinkled...... 1. S. asper. 
Auricles obtuse; achenes transversely wrinkled................-. 2. 8. oleraceus, 
1. Sonchus asper (L.) All. Fl. Pedem. 1: 222. 1785. 
Sonchus oleraceus asper L. Sp. Pl. 794. 1753. 
TyPE LocALITy: European. 
New Mexico: Farmington; Carrizo Mountains; Pecos; Santa Fe; Sandia Moun- 
tains; Mangas Springs; Berendo Creek; Cloverdale; Mesilla Valley; Fresnal; Round 
Mountain. . 
A common weed in gardens and cultivated fields, widely introduced into North 
America from Europe. 
2. Sonchus oleraceus L. Sp. Pl. 794. 1753. 
Type Locauity: ‘“‘ Habitat in Europae cultis,”’ 
New Mexico: Kingston; Patterson. 
Introduced from Europe. 
3. Sonchus arvensis I.. Sp. Pl. 793. 1753. 
Tyrer Locauity: ‘Habitat in Europae agris argillosis.’’ 
New Mexico: Shiprock (Standley 7825). 
Abundant along irrigating ditches in this one locality; introduced from Europe, 
