140 GAMOPETALOUS EXOGENS 



spine, the branches about an inch long, and very sharp. Heads of flowers axillary, 



mostly solitary. 



Hob. Farm-yards, and waste places. Nat. of Europe. Fl. Sept. Fr. Octo. 



Obs. This execrable foreign weed has found its way into our 

 County, but is happily yet rare ; and it behooves every good citizen 

 to extirpate it, wherever it may appear. Some years since, the 

 authorities of on.e of our cities where it was becoming a great 

 nuisance, in the streets enacted an ordinance against the plant, 

 denouncing it by the name of Canada Thistle! The misnomer 

 probably did not impair the efficacy of the ordinance : But it would 

 be more reputable to all concerned, if they could avoid confounding 

 objects which are essentially distinct, -and learn to designate even 

 weeds by their proper names. 



SUBTRIBE 2. HELIAN'THEAE. 



Beads mostly radiate, the disk-florets always perfect; anthers blackish, without 

 tails at base; pappus none, or crown-form, or consisting of awns, or awn like chaff, 

 never capillary, nar of uniform distinct chaffy scales. Receptacle chaffy. Leaves 

 often opposite. 



2O1. HEMOP'SIS, Persoon. 

 [Gr. Helios, the sun, and opsis, aspect; resembling the sun, or sun-flowers.] 



Heads many-flowered; ray-florets 10, or more, pistillate. Involucral 

 scales in 2 or 3 series, the outer ones foliaceous, and somewhat 

 spreading, the inner, shorter than the disk. Akenes of the disk 

 4-angled, smooth; pappus none, or a mere border. Receptacle con- 

 vex ; chaff long, linear. Perennials : resembling Helianthus ; leaves 

 opposite, petiolate; flowers yellow. 



1. H. laevis, Pers. Smoothish ; leaves lance-ovate or oblong- 

 ovate, serrate ; involucre pubescent, the outer scales lance-oblong, 

 spreading, subserrate at apex. 

 SMOOTH HELIOPSIS. False Sunflower. 



Stem 2 to 4 feet high, dl-or tri-chotomously branching at summit. Leaves 2 or 3 

 to 6 inches long, 3-nerved, obtuse at base, or abruptly narrowed to a petiole half 

 an inch to an inch in length. Heads of flowers m,iddle-sized, pn long naked term- 

 inal peduncles; rays an inch to an inch and a half long. Akenes of the disk 4-an- 

 gled, of the ray 3-angled, with the outer side convex, all truncate at apex, red- 

 dish-brown. 

 Hob. Banks of streams : frequent. Fl. July. Fr. Sept. 



202. RUDBECK'IA, L: 



[In honor of Olaus Rudbeck, father and son; Swedish Botanists.] 

 Heads many-flowered ; ray-florets neutral. Involucral scales in about 

 2 series, foliaceous, spreading. Akenes 4-angled ; pappus a minute 

 crown-like border. Receptacle more or less conical ; chaff short, 

 concave, not rigid. Chiefly perennials : leaves alternate ; rays yel- 

 low, generally long and drooping. 



f Disk oblong-conical, greenish-yellow. 



1. R. laciniata, L. Stem smooth ; lower leaves pinnatifid, 



upper ones 3- to 5-lobed, or lance-ovate and entire; pappus cre- 



nate. 



LACINIATE RUDBECKIA. Jagged-leaved Cone-flower. 



