2T8 



WEEDS AXD USEFUL PLAifTS. 



Thorny Amaraxtus. 



Root annual. Stem 18 inches -2 or 3 feet high, often purple. Leaves 1-2 inches long, 

 rather obtuse, mucronate, entire, roughish-dotted, with glaucous blotches beneath 

 petioles about as long as the leaves, with 2 subulate spines at base, one fourth to half an 

 inch in length. Flowers small, clustered in oblong terete, erect terminal and sublermina] 

 spikes. 



Cultivated lots, way-sides and waste places : introduced. Native of India. Fl. August. 

 Fr. October. 



Ohs. This foreigner is naturalized in many places — especially in the 

 unfrequented streets and outskirts of our sea-port towns, — and is grad- 

 ually extending itself into the country. It is a vile nuisance -wherever 

 it prevails, and cannot be too sedulously guarded against. 



Ylowers in dose and small axillary clusters; stame'ns and sepals 3, 

 or the former only 2. 

 5. A. al'bus, L. Pale green and smooth, much branched ; leaves obo- 

 vate and spatulate-oblong. emarginate, setaceously mucronate ; flowers 

 triandrous, in small axillary clusters. 

 White Amaraxtus. 



stem 1-2 or 3 feet high, rather stout, pale green or whitish, generally much branched 

 — the principal branches near the base, spreading. Leaves half an inch to an inch and a 

 half long, entire, narrowed at base to a slender _pe<ioZ€, one fourth of an inch to an inch 

 and a half long. ' Flowers pale green, inconspicuous, in' small axillary bracteate clusters ; 

 tracts subulate-lanceolate, spinescently acuminate, longer than the flowers. 



Barn-yards, cultivated fields, &c. !fL August. i<'/-. September. 



Obs. A worthless common weed, considered by some as a native of 

 this country, but it has all the appearance of a naturalized plant, and 

 probably came from tropical America. 



Order LX. POLTGONA'CE^. (Buckwheat Family.) 



Herbs vf\th alternate, usually entire, leaves, with stipules cohering and forming sheaihs 

 (ochrese) around the stem above its swollen' joints ; ^ou'ers generally perfect, with a more 

 or less persistent 3-6-cleft calyx ; stanmu 4-12 inserted on the base of the calyx ; ovary 

 1-celled, bearing 2- S styles, becoming akene-like in fruit. Seed smgle, erect, straight, with 

 the embryo curved or straightish, on the outside of the aVoumen, or rarely in its centre, 

 ■i=Sepa!s mostly 5. 



Embryo curved around one side of the albumen. Cotyledons slender 



or flat. 1. POLTGOXTil. 



Embryo in the albumen. Cotyledons broad and twisted-plaited. 2. Fagoptrum 

 **Sepals 6. 



Fruit 3-angled, wingless. 3. EtriEES. 



Fruit 3-angled, winged at the angles. 4. RHEtra. 



1. POLT'GONUM, L. Kxot-weed. 



[Greek, Polys, many, and Gonu, a knee or joint : the stem being much jointed.] 



Calyx often colored, embracing the fruit. Stamens 4-9, mostly 8. 

 Ovary 1-celled, compressed or triquetrous ; styles 2-3, more or less 

 united below. Akenes lenticular or triquetrous, according as the styles 

 are 2 or 3 ; embryo in a groove of the albumen, and curved half way 

 around it. Flowers often with sheathing bracts; pedicels articulated. 



