410 ORDER LXVIII. COMPOSITE. 



Ge.nus XC— PYERHOPAP'PUS. D. C. {Borkhausia.) 

 (From purros, reddish, and papptis.) 



Involucre many-leaved, with a dorsal tooth near the summit, 

 surrounded at the base with a few short subulate scales. Pap- 

 ims haiiy, stipitate. Receptacle naked. Florets perfect. 



1. P, Carolinia'nus, (D. C.) {B. Car oUni ana, Is nii.) Stem erect, few- 

 flowered, pubescent toward the summit. Leaves oblong-lanceolate, old 

 ones pinnatifid, pubescent along the margins, narrow. Flowers few, 

 solitary, on the summit of the branches ; florets numerous. Seed com- 

 pressed, striate. — Yellow. 2+. March — July. Common. 



Genus XCI— LACTU'CA. Tourn. 

 (From lac, milk, in allusion to the milky juice.) 



Involucre cylindrical, imbricate, scales membranaceous at the 

 margin. Receptacle naked. Florets perfect. Seeds smooth ; 

 pappus simple, stipitate. 



1. L, elonga'ta, (Muhl.) Stem glabrous. Leaves long, smooth be- 

 neath, the lower ones runcinate, amplexicaul, entire, toothed, the upjier 

 ones lanceolate ; involucre imbricate, reflexed when old ; florets nu- 

 merous. Flowers in corymbose panicles. Seeds compressed ; pappus 

 stipitate, hairy. — Yellow. If. July — Sept. 4 — '7 feet. Fire-weed. 



2. L. graminifo'lia, (Mich.) Stem erect, simple, glabrous. Leaves 

 gessile, long, tapering to an acute point, narrow, sometimes amplexicaul, 

 usually undivided. Flowers in loose, leafless panicles; leaves of the 

 involucre subulate. Seeds compressed, lanceolate. — Purple, ir. April 

 — Sept. In dry soils. 



3. L. sagittifo'lia, (Ell.) Stem erect, terete, glabrous. Leaves ses- 

 sile, sagittate, tapering toward the apex, entire, glabrous. Flowers in 

 loose, terminal panicles; involucre with glabrous, subulate leaves. Seed 

 compressed ; pappus hair3\ — Yellow. If. July — ^Sept. Middle Car- 

 olina. 4 — 6 feet. 



Genus XCII— MULGE'DIUM. Cass. 

 (From rmdgeo, to milk.) 



Heads many-liowered. Involucre many-leaved, imbricate. 

 Receptacle alveolate, naked. Achenia glabrous, compressed, 

 with the summit extending into a short beak. Pappus capil- 

 lary. Herbaceous plants, with undivided or pinnatifid leaves. 

 Floivers blue. 



1. M. acximina'tum, (D. C.) {Sonchus acuminatus, Willd.) Radical 

 leaves slightly runcinate, spatulate, ovate, sometimes angled, acutely 

 toothed. Petiote winged, upper surface glabrous, lower pubescent. 

 Cauline leaves ovate, acuminate, toothed in the middle, petioled. — Pur- 

 ple. If. Aug. — Sept. Rich soils. 



2. M. Florida'num, (D. C.) {Sonchus Floridanns, L.) Stem erect, 

 glabrous. Leaves narrow, lanceolate, Ivrnte, sometimes with 1 or 2 

 runcinate segments, acutely denticulate. Flowers in long slender j^ani- 

 cles. Peduncles scabrous. — Blue. 2T. July — Sept. Upper districts 

 Car. and Geo. 3 — 5 feet. 



