CICHORIACEAE 1 85 



Leaves not pinnatifid. 3. L. aagittifoUa. 



Leaves pinnatifid. 4. L. Canadensis. 



Flowers blue ; achenes short-beaked. 5. L. pulchdla. 

 Flowers blue ; achenes beakless. 



Leaves not pinnatifid. 6. L. villosa. 



Leaves deeply ly rate-pi nnati fid. 7. L, Floridana. 



1. L. virosa L. PRICKLY LETTUCE. l-3 high : leaves irregularly 

 denticulate to sinuate-denticulate, clasping at base, spiny on midrib and 

 leaf margins : achenes striate, linear-ovate. Has become a very abundant 

 weed in the last few years. July-September. 



2. L. Ludoviciana ( Nutt. ) DC. 2-5 high : leaves oblong, clasping 

 at base, deeply pinnatifid : achenes oval. Rarely found as a waif at Shef- 

 field. July-September. 



3. L. sagittifolia Ell. 2-10 high : leaves oblong-lanceolate, clasp- 

 ing at base, denticulate : achenes oval. Not uncommon in dry soil. 

 June-October. 



4. L. Canadensis L. Like the last, but leaves deeply sinuate-pinna- 

 tifid. Abundant in dry soil. June-October. 



5. L. pulchella (Pursh) DC. l-3 high, glabrous: leaves linear- 

 lanceolate, entire to runcinate-pinnatifid : achenes flat, lanceolate oblong. 

 Found as a waif at Sheffield. June-September. 



6. L. villosa Jacq. 2-10 high, glabrous : leaves ovate, pointed, 

 denticulate, tapering or abruptly narrowed into a winged petiole, some- 

 times with one or two additional lobes at base : achenes oblong, thick, 

 little flattened. In woods throughout, but not common. July-Sep- 

 tember. 



7. L. Floridana (L.) Gaertu. Like the last but leaves deeply lyrate- 

 piunatifid. Common in moist woods. July-September. 



6. NOTHOCALAIS Greene. 



Perennial herbs with linear-lanceolate, woolly, crisped-margined leaves, 

 and large heads of yellow flowers. Involucre imbricated in several series. 

 Achenes fusiform, 10-striate. Pappus composed of narrow scales mixed 

 with bristles. 



1. N. cuspidata (Pursh) Greene. FALSE DANDELION. 1 high from 

 a thickened caudex. Not uncommon in barrens throughout the south- 

 western part. April-May. 



7. SITILIAS Raf. 



Perennial herbs with large heads of yellow flowers. Principal in- 

 volucral bracts in one series, with smaller ones at base. Achenes fusi- 

 form, 5-ribbed, tipped with a long filiform beak. Pappus brownish, 

 surrounded at base by a soft-villous ring. 



1. S. Carollniana (Walt.) Raf. FALSE DANDELION. l-3 high, 

 branched : leaves oblong-lanceolate, entire to pinnatifid. Found as a 

 waif along the railroad near Dodson. June-September. 



