WEEDS OF MAINE. 273 



Some weeds are much more productive than the Pigweed. The 

 extirpation of the Pigweed is easily effected, when the plants are 

 small, by simply cleaning the ground of them with a hoe or culti- 

 vator. 



Order 30. AMARANTHS— Amaranthace^. "Genera 46, 

 species 480, most abundant within the tropics. The properties 

 are not important. A few are cultivated for their richly-colored 

 imperishable flowers ; others are mere weeds." — ( Wood.) 



93. Gkeen Amaranth. -Pigweed — Amaranthus retroflexus. Annual, Stem two to four 

 feet high, branched. Leaves two to five inches long, ovate or rhombic-ovate. Flowers 

 green, small, in close clusters in a stiff jjanicle. Bracts awned. 



Equally prevalent with the Chenopodium album, and should be 

 destroyed in a similar manner. 



Order 31. SORPtELWORTS— Polygonace^. According to 

 Meisner, this order contains 690 species. They are chiefly natives 

 of the northern temperate zone. The juice is watery; acrid or 

 rubefacient in the Smartweed, Water-pepper, Knotweed, &c.; 

 agreeably acid in the Sorrel (Eumex), and Rhubarb. The seeds 

 of the Buckwheat furnish a nutritious flour. 



94. Lady's THtrMB. -Spotted Knotweed. -Smartweed — Polygonum. Per sicaria. Annual. 

 Stem one to two feet high, smooth, branched, often purplish. Leaves two to four inches 

 long, lanceolate, usually marked with a dark triangular or lunar spot near the middle. 

 Flowers generally rose colored, in a dense spike one to two inches long. 



A very common and troublesome weed, naturalized from Europe, 

 growing in waste and cultivated grounds, about buildings, fences, 

 &c. The P. Pennsylvanicum much resembles the Spotted Knot- 

 weed, but may be distinguished by its larger growth and unspotted 

 leaves. Both species are worthless weeds, and should be carefully 

 eradicated. Polygonum Hydropiper. -Water Pepper. -Smartweed, 

 may be known from the two preceding by its minutely pellucid 

 punctate leaves, and slender, nodding, loosely-flowered spikes. It 

 generally inhabits moist grounds and ditches, but is frequently 

 found with the preceding. Like the P. Pennsylvanicum, it is 

 indigenous. The juice is extremely acrid, "sometimes causing 

 obstinate ulcerative inflammation when incautiously applied to the 

 skin." — [Darlington.) 



95. Goose-grass — Door-weed — Knot-grass — Polygonum avkulare. Root annual, 

 long and fibrous, very tough. Stem spreading in' every direction, generally prostrate, 

 much branched, leafy. Leaves alternate, one half an inch to an inch and a half long, 



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