442 COMPUSITJ-:. Lacluca. 



Kiul imbricated scales, the lowest ovate, the upper successively longer and oblong- 

 lanceolate : pappus of rather rigid light-brownish bristles. 



Gravelly hills, or in sand, Mono Lake (IJolander), anil through the western pail of Nevada, 

 near the northern borders of which it was first collected by AiUiall. 



123. LACTUCA, Tourn. LicrnicK. 

 Head few - niauy-llowered. Involucre cyliudraceous or sometimes canipanulate, 

 seldom thickened at base; the scales thinnish, in two or few series, the outer shorter. 

 Receptacle Hat, naked. Akenes ilat, I'rom broadly oval to lanceolate, the sides few- 

 several-ribbed, the apex contracted and commonly i)ii)longed into a beak, its 

 summit abruptly dilated into a disk which boars the (usually bright white) coi)ioU8 

 pappus of very soft and tine uniform antl merely denticidato capillary bristles, falling 

 separately. — Leafy-stemmed herbs, glabrous, or with some bristly hairs, with panic- 

 idate middle-sized heads of yellow or blue flowers. — IJenth. & Hook. Gen. PI. ii. 

 524. Lactuca & MuUjtdium, Cass., DC, Torr. & Gray, Fl. ii. 495, 497. 



A large genus in the Old World, represented by a few species in North America ; but no 

 genuine Lactuca (with broad and Hat akenes and long filiform beak) is known on the Pacific side 

 of the continent. The only Californian species being intermediate between true Lacluca and 

 MuUjcdiuiu, it is the more expedient to follow Benthani in suppressing the latter genus. 



1. L. pulchella, DC. A foot or two high, wholly glabrous: stem commonly 

 simple, leafy, bearing a loose and naked panicle of several or numerous rather largo 

 heails : leaves pale, from oblong-lanceolate to linear, either entire, runcinately few- 

 toothed, or sparingly pinnatiiid : pedicels scaly-bracteolate : involucre cylindraceous, 

 20-30-ilowered, the outer scales successively shorter: corollas blue: akenes oblong- 

 lanceolate, rather thick -edged, several-ribbed on each face, miiuitely scabrous, taper- 

 ing into a rather long stout beak, the ui)pt^r part of which is pale and less hrm in 

 texture. — Jj, iiite<iri folia, Nutt. (ien. KSonchiis pulrhellns, Pursh. A'. SihiricuH, 

 Itichardson, not of Linn. JIuli/edluia pulcktUuvi & kderophyUum, Nutt. 



Eastern part of the Siena Nevada, north to Oregon, and east nearly to the Mississippi. Heads 

 three fourths of an inch long. The root is apparently biennial or annual. 



L. LEUCOPHAiA {Sonchus Icucophwus, WilKl., and MuUjediuin leucophceum, DC.) extends across 

 the continent from New England to the coast of Oregon, and may occur in northern California. 

 It is a tidl and coarse species, known by its runcinate leaves, ample panicle of rather small heads of 

 pale blue or whitish (lowers, rusty-colored pappus, and beakless akenes having only a short neck. 



124. SONCHUS, Linn. Sow-Tiiistle. 

 Head many-flowered. Involucre lliishy-thickened at base, ovoid, conical, or cam- 

 jianulate ; its scales more or less imbricated, the outer shorter. Eecejitaele flat, 

 naked. Akenes compressed, oval or oblong, several - many-ribbed or nerved, desti- 

 tute of a beak or neck and of a dilated pappus-bearing disk. Pappus of copious 

 very fine and soft white capillary bristles, most of them somewhat united at base so 

 as to be deciduous together, a few separate and stronger ones sometimes less decid- 

 \U)U3. — Leafy-stennucd and mostly glabrous herbs, generally of coarse aspect, with 

 somewhat coryndioso or paniculate heads of yellow flowers. Probably none of them 

 indigenous to this country, but the first and second species, the common annual 

 So^v-Thistles, are weeds almost all over the world. 



1. S. oleraceus, Linn. Two or three feet high : leaves runcinate-pinnatilid or 

 rarely undivided, beset with short and soft spiny teeth, clasping by a heart-shaped 

 base with acute auricles : akenes minutely rugose-scabrous. 



Waste grounds around dwellings ; but no Californian specimens yet seen. 



