252 COMrOSITyK. (rOMrOSITK 1 A-MII.V.) 



ribbed or aii^rlccl, murirato nn the ribs ; the apex nbrii|)lly prodticetl into a lon;^ 

 beak. Pappus of copious white hairs. — Steniless peruiiuia! herbs. Scapes hol- 

 low, bearin:^ a siiij^le licail 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. Achcnia oblong, nearly terete, .'j-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 pedunele-likc 

 branches. Flowers yellow. 



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

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

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

 10-2° high. 



89. LACTUCA, L. Lettlce. 



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°-80), simple 

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

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

 — Var. ixTKGRiFOLiA. Lcavcs 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. MULGEDIUM, Cass. 



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

 short. Receptacle naked. Achenia smooth, laterally compressed, narrowed 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 ovatc-lanccolatc, acuminate, toothed, on winged petioles, the lowest some- 

 times sinuate-lobcd ; heads racemcd, on spreading peduncles. (Sonchus, Ell) 



