252 COMPOSITE. (COMPOSITE FAMILY.) 



ribbed or angled, muricate on the ribs ; the apex abruptly produced into a long 

 beak. Pappus of copious white hairs. Stemless perennial herbs. Scapes hol- 

 low, bearing a single head of yellow flowers. Leaves all radical, oblong or 

 lanceolate, entire or pinnatifid. 



1. T. Dens-leonis, Desf. Leaves pinnatifid, the lobes acute, toothed; 

 heads showy. Damp soil, sparingly naturalized. 



88. PYRRHOPAPPUS, DC. 



Heads many-flowered. Involucre double, of numerous subulate scales ; the 

 inner ones erect and partially united, often with a callous appendage at the apex. 

 Receptacle flat, naked. Achenia oblong, nearly terete, 5-furrowed ; the apex 

 narrowed into a long filiform beak. Pappus of copious soft reddish or brownish 

 hairs. Smooth annual herbs. Leaves oblong or lanceolate, commonly toothed 

 or pinnatifid. Heads solitary, terminating the naked stem or peduncle-like 

 branches. Flowers yellow. 



1. P. Carolinianus, DC. Stem branching ; leaves lanceolate, mostly 

 toothed or pinnatifid ; achcnia shorter than the filiform beak. (Borkhausia, 

 Ell.) Fields, Florida to Mississippi, and northward. April - July. Stem 

 1 - 2 high. 



89. LACTUCA, I,. LETTUCE. 



Heads few- or many-flowered. Scales of the cylindrical involucre imbricated ; 

 the outer ones short. Receptacle naked. Achenia compressed parallel to the 

 scales, smooth, abruptly narrowed into a filiform beak. Pappus of copious soft 

 white hairs. Tall herbs, with entire or pinnatifid leaves. Heads paniculate. 

 Flowers white, purple, blue, or yellow. 



1. L. elongata, Muhl. Smooth or nearly so; stem tall (4-8), simple 

 or paniculate ; leaves elongated, lanceolate, sessile or partly clasping ; the upper 

 ones mostly entire ; the lower pinnatifid ; panicle long, leafless ; flowers yellow. 

 Var. INTEGRIFOLIA. Leaves all undivided, or the lowest pinnatifid ; flowers 

 yellow or purplish. Var. GRAMINIFOLIA. Smaller (2- 3), leaves linear or 

 linear-lanceolate, rather rigid, all entire, or the lowest ones sparingly toothed 

 or pinnatifid; flowers purple. Dry soil, Florida, and northward. July -Sept. 



90. MTJLGEDIUM, Cass. 



Heads many-flowered. Scales of the involucre imbricated, the outer ones 

 short. Receptacle naked. Achenia smooth, laterally compressed, nan-owed into 

 a short beak, which is expanded into a ciliate disk at the apex. Pappus of co- 

 pious white or tawny hairs. Tall herbs. Leaves pinnatifid or undivided. 

 Flowers mostly blue. 



* Pappus white. 



1. M. acuminatum, DC. Smooth; stem panicled above ; leaves ovate 

 or ovate-lanceolate, acuminate, toothed, on winged petioles, the lowest some- 

 times sinuate-lobed ; heads racemed, on spreading peduncles. (Sonchus, Eli] 



