Lactuca. COMPOSITE. 443 



-1 -t Involucre more imbricated, commonly three-fourths inch high; outermost and intermediate 

 bracts ovate and ovate-lanceolate. 



L. LiUdoviciana, DC. Glabrous, leafy to the open panicle, 2 to 5 feet high : leaves all 

 oblong and auriculate-clasping, 3 or 4 inches long, siiiuate-pinnatifid, somewhat spinulosely 

 dentate, more or less bristly-ciliate, more or less hispidulous-setose on the midrib beneath: 

 peduncles squamose-bracteolate : flowers yellow : akeues oblong-oval, about equalled by the 

 filiform beak. Prodr. vii. 141; Torr. & Gray, I.e. Sonchus Ludovicianus, Nutt. Gen. ii. 

 125. Gulathcnium Ludovicianum, Nutt. Trans. Am. Phil. Soc. 1. c. Moist or dry banks of 

 lakes and streams, Dakota, Nuttall, Geyer. Iowa, Arthur. Black Hills of the Platte, Hay- 

 den. Ivio Limpio, S. W. Texas, Bigelow. 



2. LACXucXsTRUM. Akcncs lanceolate-oblong, flat, marginless, tapering 

 into a beak nearly like that of the preceding section, but not longer than the 

 breadth of the body : root perennial : involucre well imbricated, glabrous. 



Li. pulcliella, DC. A foot or two high, very glabrous, glaucescent, leafy up to the open 

 corymbiform panicle : leaves from linear-lanceolate to narrowly oblong, entire or runciuate- 

 deutate, or some lower ones pinnatifid ; cauline sessile, with base not auriculate-clasping, dis- 

 posed to be vertical : branches of the loose panicle and peduncles squamose-bracteolate : 

 involucre two-thirds inch high, 15-20-flowered ; its outer bracts ovate-lanceolate: flowers 

 bright blue or violet-purple : akenes barely 2 lines long, striate-nervose ; the tip of short 

 beak soft and usually whitish. Prodr. vii. 134; Gray, Bot. Calif, i. 442. L. integrifolia, 

 Nutt. Gen. 1. c., not Bigel. Sonchus jiii/chi-l/its, Pursh, Fl. ii. 502. S. Sibiricus, Richards.; 

 Hook. Fl. i. 293, not L. Mulgedium pnh-ln-lliun, Torr. & Gray, Fl. ii. 497. M. pulchclliim & 

 M. heterophfillitm, Nutt. Trans. Am. Phil. Soc. vii. 441. Alluvial ground, Upper Michigan 

 to the Hudson's Bay region in lat. 60, south to New Mexico, west to Brit. Columbia and 

 mountains of Nevada and adjacent California. 



3. MULGKDIUM. Akenes thickish, oblong, with some strong ribs and nerves, 

 contracted at summit into a stout short beak mainly of the texture of the body, 

 or into a mere (even obscure) neck under the dilated pappiferous apex : involucre 

 (glabrous, 15-25-flowered) and habit of Scar tola, or more branching: glabrous 

 biennials or annuals, with or without some hairs or weak bristles on the mid- 

 rib and veins beneath, commonly with bluish flowers. Here characterized for 

 the American species only of Mulgedium, Cass. (Agathyrsus, Don), leaving the 

 older name, CicerUta, Wallr., for the Old World species of less affinity to true 

 Lactuca. 



* Flowers light blue : pappus bright white : cauline leaves on margined or winged petioles, not 

 clasping nor auriculate at insertion: heads loosely paniculate. 



L. Ploridana, G/ERTN. Stem 3 to 7 feet high : leaves deeply lyrate-pinnatifid ; lobes 

 simply or doubly dentate, lateral ones ovate, terminal dilated-deltoid and acuminate: invo- 

 lucre half-inch long : akenes acuminate into a manifest beak. Gacrtn. Fruct. ii. 262, name, 

 but the akenes figured, t. 158, probably from herb. Banks, are of L. leucophina. Sonchus 

 Floridanus, L. Spec. ii. 795; Willd. Spec, iii. 1520; Michx. Fl. ii. 85, in part; Ell. Sk. ii. 

 225. Muhjedium lyratum, Cass. Diet, xxxiii. 297. M. Floridanum, DC. Prodr. vii. 249; 

 Torr. & Gray, Fl. ii. 498, excl. vars. Arjalhi/rsns Floridanus, Beck, Bot. 171. ( nthtthenium 

 Floridamnn, Nutt. Trans. Am. Phil. Soc. I.e. 443. Alluvial ground and along streams, 

 Penn. to Illinois, Florida, and Texas. 



L. acuminata, GRAY. Leaves from ovate-oblong to oblong-lanceolate, acuminate at both 

 ends, or cauline not rarely sagittate or hastate, sharply and sometimes doubly serrate, occa- 

 sionally some of the lower cleft at base, forming a pair of lateral lobes : involucre 5 lines 

 high : akenes beakless and with hardly a neck : otherwise nearly like the preceding. Proc. 

 Am. Acad. xix. 73. L. rilfosa, Jacq. Hort. Schcenbr. iii. t. 367 ; Beck, Bot. 170, but the plant 

 mostly glabrous or nearly so. Sonchus acumina/iis, Wilkl. Spec. iii. 1521; Ell. 1. c. S. 

 Floridanus, Michx. 1. c., in part. Mti/f/ed/um urmnhintmn, DC. 1. c. ; Torr. & Gray, 1. c. 

 Borders of woodlands, New York to Illinois and Florida. 



