478 SYXGEXESIA [Sesecioxideje 



ScnopiiuLors Xantiuum. Vvlgb — Clot-wccd. Cockle-bur, 

 Ga//.-Lampourde. Germ.-Dic Spitzklette. JK*/;.-Lampazo pequeno. 



Root annual. Stem I to 3 feet high, angular, scabrous pubescent, branching. 

 Leaves 3 to 6 inches long, and nearly as wide as long, alternate, bruad-ovate, 

 angulate-dentate, often somewhat 3-lobed, roughish-pubesccnt on both! e idea, sub- 

 cordate at base, but cuneately produced in the centre, at the union of the 3 prin- 

 cipal nerves; petioUs 2 to 4 inches long, striate, scabrous-pubescent. Heads of 

 flowers in axillary racemose clusters,— the staminate ones at the summit, the 

 pistillate ones at the base, of the racemes ; involucre of the pistillate heads 2-fiow- 

 cred, elliptic-oblong, persistent, uncinately spinose, with 2 stouter straight spin- 

 osj beaks at apex, 2-celled, each cell containing an oblong compressed ukene. 

 Hub. Farm-yards ; roadsides, &.C. frequent. Ft. August— Sept. Fr. Octo. 



Obs. This is an obnoxious weed— though not much inclined to spread ; and, 

 with a little attention, is easily to be kept in subjection. The burs art a great 

 annoyance in the fleeces of sheep. Mr. Nuttall says it is Indigenous in the West ; 

 but to me it has the appearance of a stranger, here. 



8. X. spixosuM, L. Stem armed with stipular tern ate spines ; leaves 

 ovate-lanceolate, finally often 3-lobed. Beck, But, p. 210. 



Spinose Xanthium. Vulgo — Thorny Clot-weed. 



Root annual. Stem 2 to 3 or 4 feet high, terete, striate, pubescent, branched. 

 Leaves 1 to 3 inches long, and 1 fourth to 3 fourths of an inch wide, alternate, 

 ovate-lanceolate, attenuate at apex, entire, or re.'uand-denticulate, finally often 

 3-lobed, or with a lobe-like tooth on each side, tne upper surface pale green, 

 sprinkled with cinereous hairs, which arc dense on the midrib, the under surface 

 clothed with a short cinereous tomcntuin, the base narrowed to a short pubescent 

 petiole, on each side of which is a triple or 3 forked spine, the branches or spines 

 about an inch long, very sharp, yellowish, or straw-colored, on a common foot- 

 stalk scarcely a line in length. Heads of flowers axillary, solitary ; involucre 

 pubescent, that of the fruit uncinate-prickly. 

 Hub. Farm-yards ; Honey- brook : rare. Fl. September. Fr. October. 



Obs. This execrable foreign weed was found, about 3 years since, partially 

 naturalized in the N. West side of this County; but it is as yet, happily, very 

 rare. It will behove our farmers to be vigilant in arresting its progress, whilst it 

 It yet within their control. It is becoming abundant in the vacant lots of Philad- 

 elphia, between Broad Street and the Schuylkill,— where it was introduced a few 

 years ago, from the South. One other species, likewise a foreigner, occurs in the 

 U. Stales. 



382. AMBROSIA. L. Mitt. Gen. 703. 

 [A poetical name: the food of the Gods ; but the application seems forced.] 



Heads homogamous, monoicous, — the pistillate ones 1-flowered, inves- 

 ted by an unarmed involucre, — the staminate ones many-flowered; 

 receptacle without bracts. Akenes subglobose. 



1. A. tuifida, L. Hairy and scabrous ; leaves 3- or 5-lobed, serrate, 

 the lobes oval-lanceolate, acuminate ; racemes elongated, paniculate. 

 Beck y Bot. p. 209. 



Tiiifid Amuuosi a. 



Root annual. Stem 3 to 6 or 6 feet high, angular, striate, hairy and scabrous, 

 branched. Leaves 4 to 6 or 6 inches I jng, and nearly as wide as long, mostly 



