tOLTGONACEJE. 323 POLYGONtJM. 



Properties. The roots of these plants are nauseous and purgative. Rhubarb of the shops 

 is the root of some unknown species of this order, native of Tariary. But the leaves and 

 stal/es of sorrel, the garden rhubarb, &c., are agreeably tan, and contain oxalic acid ; the 

 petioles of tlie latter, together with the farinaceous seeds of the buck-wheat, are well known 

 articles of food. 



Conspectus of the Genera. 



( 6. Stigmas 3, multifid. 3 outer sepals smaller. Ritmex. 2 



( 6. Stamens ) 9. Stigmas multifid Rheum. 3 



Sepals ( mostly 5, united at base, persistent and enclosing the fruit. . Polygonum. 1 



1. POLY'GONUM. 

 Calyx 4 — 6-sepalec], resembling a corolla; stamens 5 — 9, 

 mosllyS; styles 2 — 3; achenia mostly triangular, enclosed 

 in the calyx. 



Gr. TToXvi, many, and yovv, knee ; that is, with many joints. Herbs with 

 jointed stems. Fls. in axillary and terminal fascicles and spikes. Ova. trian- 

 gular or compressed. Styles generally 3, 2 in some species, very short, 

 tiliform. 



* Flowers axillary. Stamens 5 — 8. Stigmas 3. Polygonum veruvi. 



1. P. avicula're. 



.S'fcm procumbent ; Zeaces elliptical-lanceolate, rough-edged, acute, sessile ; 

 flmcers subsessile. A common weed in fields, highways and door-yards. 

 Stems slender, ^ — 1^ foot long, striate, smooth, branching, with sliort, white, 

 torn, remotely nerved stipules at the joints. Leaves smooth except tlie edges, 

 I — 1 inch long and J- as wide. Flowers reddish, small, 2 or 3 together in the 

 axils of the leaves, appearing all summer. Ann. Knot-grass. 



/3. glaucum (P. glaucum. jXult.) ; leaves fleshy, glaucous, revolute on the 

 margin. Grows on the sea-coast. Long Island. 



2. P. ERE'cTUM. p. aviculare. /3. latifolium. P. 

 Stern mostly erect, branched ; leaves smooth, broadly oval, petiolate ; flowers 



edicellate ; stamens mostly 5. A species remarkably distinct in appearance 

 rom the last, in similar situations, but seldom growing with it. Stem 1 — 2^ 

 feet high, branched, smooth. Leaves 1 — 2 inciies long and about ^ as wide, 

 rather obtuse, the petioles — i inch long Flowers 2—'i together, pedicellate, 

 in the axils of the leaves, yellowish. Jn. — Sept Per..' Erect Knot-grass. 



3. P. te'nue. 



Stem slender, erect, branched, acute-angled; leaves linear-lanceolate, erect, 

 acuminate; stipules tubular, villose at top; flowers alternate, subsolitary, 

 axillary. A small, slender plant, on rocky soils, Sugar-loaf Mt., tSitc. Stem 

 i — 1 foot high. Leaves 1 — 1^ inch long, 1 — 2 lines wide, 3-nerved, sessile. 

 Flowers white. July, Aug. Ann. Slender Foiygonum. 



* * Flowers in axillary or terminal spikes. Stamens 5 — 8. Stigmas mostly 

 2. Peksicaria. 



4. P. PUNCTA'TUM. Ell. P. Hydropiper. Mx. 

 Stem branched, often decumbent at base; leaves lanceolate, punctate with 



pellucid dots, waved and scabrous on the margin; spike loose, inteirupted, 

 drooping; stamens (J — 3; styles 2, united half way up. A plant well known 

 for its acrid taste, growing in ditches, low grounds, among rubbish, &c. 

 Stem smooth, swelling above the joints, 2 leet high, and, like the leaves, 

 sprinkled with glandular dots in which the acrimony is said to reside. Leaves 

 2—3 inches long and not more than a fifth as wide. Flowers green, tinged 

 with purple and white. Aug. Sept. Ann. Water Pepper. 



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