278 WEEDS AND USEFUL PLANTS. 



THORNY AMARANTUS. 



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 subtermiiud 

 spikes. 



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

 Fr. October. 



Obs. 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. 

 * * * Flowers in close and small axillary clusters ; stamens 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 AMARANTHS. 



Steml-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 petiole, one fourth of an inch to an inch 

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

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



Barn-yards, cultivated fields, &c. Fl. August. Fr. September. 



Obs. A worthless common -weed, considsred by somo as a native of 

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

 probably came from tropical America. 



ORDER LX. POLYGONA'CE^E. (BUCKWHEAT FAMILY.) 



Herbs with alternate, usually entire, leaves, with stipules cohering and forming slwatlis 

 (ochrcaj) around the stem above its swollen joints ; powers generally perfect, with a more 

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

 1-celled, bearing 2- 3 styles, becoming akenc-like in fruit. Seed single, erect, straight, with 

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

 *Sepals mostly 5. 

 Embryo curved around one side of the albumen. Cotyledons slender 



or flat. 1. POLYGOXUM. 



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



**Sepals 6. 



Fruit 3-anglfd, wingless. 3. RUMEX. 



Fruit 3-anglcd, winged at the angles. 4. RHEUM. 



1. POLY'GONUM, L. KNOT-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 wav 

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



