442 Annals of the Carnegie IVIuseum. 



writer lias been able to ascertain from his own studies in the field 

 and herbarium the belief has become quite strong that we are dealing 

 here with two distinct forms, whose relationships are probably best 

 indicated as those of species and variety, the latter limited to the in- 

 terior in its geographical distribution. 



The writer has had the privilege of examining the collections of 

 Lactuca spicata in the herbaria of the Philadelphia Academy of Nat- 

 ural Sciences, the National Herbarium at Washington, and the Ohio 

 State Herbarium at Columbus, and as far as could be determined 

 from the specimens, just as from the numerous specimens in the 

 Carnegie Museum, the color of the flowers was yellow in all plants 

 collected in or to the west of the Appalachians. The only blue- 

 flowered specimens seen were from the region distinctly to the east 

 of the mountains. 



The variety aiirca, as it occurs in the Pittsburgh region, is : 

 Biennial, perhaps rarely annual : stems stout, striate, glabrous, green 

 to brownish, often somewhat glaucous, about i to 5 meters high, 

 sometimes 2 cm. or more in diameter at the base, erect, strict, un- 

 branched up to the inflorescence ; leaves in general outline obovate, 

 acuminate, more or less deeply runcinate-pinnatifid and lobed, more 

 or less sinuately toothed, often doubly so, the leaves reaching a length 

 of 3 dm. or more, the terminal lobe being usually more or less unlobed 

 and equilaterally triangular and comprising one-third to one-half the 

 length of the leaf ; below the lamina narrowing to a widely margined 

 petiole, and more or less auriculate-clasping base, the leaves usually 

 pubescent on the veins and mid-rib beneath ; the inflorescence forming 

 an erect, rather densely spicate panicle, the upper leaves narrowing to 

 lanceolate-acuminate bracts with auriculate-clasping bases; pedicels 

 rather stout, divaricate to ascending, with two to four minute linear- 

 lanceolate bracts; heads numerous, in flower about i to 1.5 mm. broad, 

 the involucre 9 to 12 mm. high, oblong-cylindric, the principal bracts 

 of an equal length and from a little shorter to as long as the pappus 

 of the ripe achenes. linear-lanceolate, sub-acute to obtuse, whitish- or 

 scarious-margined, the outer bracts few, much shorter, all glabrous, 

 the ligules yellowish-green or sometimes golden, .soon withering; 

 achenes oblong, about 1.5 mm. wide by 4.5 to 5 mm. long, flat, quite 

 curved usually, the middle portion distinctly longitudinally striate, the 

 whole surface rugose with minute short transverse ridges, grayish- 



