176 WEEDS AND USEFUL PLANTS. 



1. 1. Hele'nium, L. Stout ; pubescent ; leaves large, oblong ovate, those 

 of the stem clasping ; akenes 4-sided. 



Elecampane. 



Stem 3-5 feet high, sulcate, branching above. Leaves 9-18 inches long, and 4-8 inches 

 wide, acute or acuminate, denticulate, hoary-tomentose beneath, the radical ones petio- 

 late. Outer scales of the involucre ovate, tomentose. Anthers produced at the base into 

 two tails, or bristle-like appendages. Akenes smooth ; pappus pale tawny. 



Roadsides, &c. Naturalized from Europe. July - August. 



Obs. Common along road-sides, and having a very slovenly aspect 

 after the flowering season is past. The large thick root has a camphor- 

 like smell and a warm, bitter taste ; it was formerly in high repute as a 

 medicine, but is now seldom used ; it is a tonic and expectorant, as 

 those medicines are called which affect the secretions of the throat. * 



8. AMBRO'SIA, Tournef. BAG-WEED. 



[Poetically, Food of the Gods; in this case something like Lucus, a non lucendo.] 



Sterile and fertile flowers in different heads on the same plant ; 

 the staminate in terminal racemes or spikes, the pistillate ones at 

 their base or in the axils of the upper leaves. STAMINATE FL. Invo- 

 lucre flattish, hemispherical, or subturbinate, composed of several united 

 scales, 5 - 20-flowered. Corolla funnel-form, 5-toothed. Receptacle 

 flattish, usually with filiform chaff among the florets. PISTILLATE FL. 

 Involucre globose-ovoid or turbinate, closed, acuminate, usually with 4 

 -8 pointed tubercles near the summit, 1-flowered. Corolla none. 

 AJcene subglobose or obovoid. Annual herbs. Leaves lobed, or pinnati- 

 fidly dissected. 



1, A. trifi'da, L. Stem tall and stout, hairy and rough ; leaves mostly 

 opposite, palmately 3-5-lobed, hairy, scabrous, the lobes oval lanceo- 

 late, acuminate ; petioles narrowly winged, ciliate ; racemes elongated, 

 paniculate. 



TRIFID AMBROSIA. Great Rag-weed. 



Stem 3-6 or 8 feet high, branched. Leaves 4-6 or 8 inches long ; petioles 1-2 inches 

 long. Staminate heads small, numerous, in long terminal paniculate racemes ; florets 

 whitish. Pistillate, heads at the base of the racemes ; the involucre turbinate-obovoid, 

 with a conical apex, 6-ribbed, the ribs terminating in so many pointed tubercles round the 

 base of the conical acumination. 



Low grounds and waste places : Canada to Georgia. Fl. August. Fr. October. 



06s. This coarse ugly weed is sufficiently common, and worthless, to 

 entitle it to the notice of every farmer who desires to keep his premises 

 clear of such nuisances. 



2. A, artemisiaBfo'lia, L, Stem paniculately branched, villous ; 

 leaves bipinnatifid, smoothish above, somewhat canescent beneath, 

 the uppermost simply pinnatifid ; petioles ciliate with long hairs ; 

 racemes somewhat spicate, paniculate. 



ARTEMISIA-LEAVED AMBROSIA. Bitter-weed. Rag- weed. 



