160 COMPOSIT.E. 



;he involucre 8 — 10, lanceolate, acute or acuminate, very pubescent and 

 glandular on the back, white and scarious at the summit. E. glaucescens 

 /? leucolepis D. C. E. linearifol'mm, Mich, (in part.) 



Sandy swamps. Long Island, N. Y., to Flor. Aug. — Oct. %..—Stem 2 feet 

 high, mostly simple, slender. Leaves 2 inches long and 4 — 5 lines wide, spread- 

 ing and sometunes recurved. Floivers white. Style much exserted. 



While-scaled Hempweed. 



11, E. pubescens MuKL. : stem pubescent ; leaves opposite, sessile, ovate, 

 acuminate, sparingly pubescent and glandular-punctate on both sides; 

 lower doubly serrate, upper slightly serrate ; corymb compound, fastigiate ; 

 heads 5-flowered ; scales of the involucre 10, linear-lanceolate, acute. 

 E. ovatum Big. 



Sandy woods. Mass., N. J., and Penn. Aug. — Oct. %. — Stem 2 feet high, 

 the lower branches opposite. Leaves thin and slightly scabrous. Flovoers white. 



Pubescent Hempweed. 



12, E. album Linn : stem pubescent at the top ; leaves opposite, subses- 

 sile, broad-lanceolate, attenuate at base, with a few coarse teeth at the 

 apex, somewhat scabrous, punctate beneath ; heads 5-flowered, in a ter- 

 minal corymb ; scales of the involucre 10, oblong-lanceolate, acuminate, 

 almost exceeding the corolla, glandular on the back. E. glandulosum 

 Mich. 



Woods. N. Y. to Flor. Aug.— Oct. %..—St€m erect, about 2 feet high. 

 Flowers in a terminal fastigiate corymb, white. Scales white at the tips. 



White-headed Hempweed. 



13, E. verbencBfolium Mich. : stem roughish-pubescent ; leaves opposite, 

 (the upper often alternate,) sessile, ovate-oblong or ovate-lanceolate, scab- 

 rous, coarsely serrate-toothed ; corymb compound, somewhat panicled ; 

 heads 5 — 6-flowered ; scales^ of the involucre 10, oblong-lanceolate, rather 

 acute, hispid-pubescent. E. ieiccrifolium and lanceolatu7ii Willd. 



Low woods. Mass. to Car. Aug. — Nov. %. — Stem 2 — 3 feet high, erect, 

 rather slender. Leaves sometimes almost incised ; the lower broad at base and 

 closely sessile. Heads somewhat clustered, corymbose. Flowei-s white. Scales 

 ecarioas on the margin, white at the tips. Michaux's name for this species has 

 the claim of priority, and, as Mr. Elliott remarks, is equally, perhaps more, ap- 

 propriate. Vervain-leaved Hempweed. 



14, E. rotundifoLium Linn. : stem densely pubescent ; leaves opposite, 

 sessile, roundish-ovate or ovate-cordate; obtuse, toothed, veined, pubescent, 

 glandular-punctate beneath ; corymb fastigiei^e ; heads 5-flowered; scales 

 of the involucre 10, acuminate. E. Marrubium Wall. 



Sandy fields. Can. to Flor. Aug., Sept. %.. — Stem 2 feet high, slender, 

 roughish-pubescent. Leaves sometimes almost orbicular, sprinkled with resinous 

 dots. Flowers in a flat-topped corymb, white. Round-leaved Hempweed. 



8. MIKANIA. WiLld.—CMmhmg Hempweed. 

 (In honor of Prof. Mikan, of Prague, a botanist of the last century.) 



Heads mostly 4-flowered. Receptacle naked, narrow. In- 

 volucre 4-leaved. Corolla with the tube short, dilated or sub- 

 campanulate at the summit, 5 -toothed. Anthers somewhat ex- 

 serted. Achenia angled. Pappus in a single series, rough. 



