POL 



OH, BOTANICAL DICTIONARY. 



POL 



377 



the Persicaria division of this germs which has a perennial 

 root. It may also be distinguished from others by the leaves 

 being hollowed at the base, and fringed with hairs at the 

 edges; they are also harsher, especially when the plant 

 grows out of the water. This species has the name of Amphi- 

 Limn, from its growing both on land and in water. We may 

 conclude that the latter is its natural situation, from its sel- 

 dom producing the fructification in dry places. From its 

 floating leaves the elder botanists thought it was apondicced, 

 but Ray rectified the mistake. Villars informs Us, that it was 

 supposed in Alsace to be injurious to cattle; but he is of 

 opinion that it is rather useful to them, on account of its acid 

 antiseptic qualities. He remarks very justly, (hat all marshy 

 situations being unwholesome, the plants which are most 

 common there, are accused of doing all the mischief. As a 

 weed, certainly few plants are more pernicious, for the roots 

 not only creep, but penetrate so deeply into the earth, that 

 they ore seldom or never eradicated : but as it rarely flowers 

 on arable land, it is a more local plant than some of the 

 same genus, of the seeds of which waterfowl are very fond. 

 Native of most parts of Europe, in ponds, ditches, and 

 rivers, and sometimes on arable land. In water its long 

 creeping roots run deep into the mud, throwing out whorls of 

 fibres here and there, whilst the leaves float upon the surface, 

 and the beautiful spikes of flowers in July and August are 

 elevated above it. Frequently however, as liny observes, the 

 roots are thrown out with the mud in clearing ditches, and if 

 liy that or any other accident the plants get out of the water, 

 the stems grow more erect, the leaves become narrower and 

 hairy, and the flowers are more sparingly produced. 



8. Polygonum Filiforme. Flowers pentandrous, digynous; 

 spikes filiform ; leaves ovate ; stipules ciliate ; stem round, 

 marked with obsolete raised lines, erect, villose, with close- 

 pressed hairs, ferruginous. It flowers in September and 

 October. It is very nearly allied to the thirteenth species. 

 Native of Japan, near Nagasaki. 



9. Polygonum Ocreatum ; Spear-leaved Polygonum. 

 Flowers pentandrous, trigynous; leaves lanceolate. Flowers 

 in July. Perennial. Native of Siberia. 



10. Polygonum Hydropiper ; Water or Bitiny Pcrsicaria. 

 Flowers hexandrous, semidigynous; leaves lanceolate, waved, 

 unspotted; spikes filiform, nodding; stem erect; root annual, 

 fibrous. This plant is readily known by its pale unspotted 

 leaves, and lax, slender, drooping spikes, of red and white 

 in conspicuous flowers. Dr. Stokes remarks, that the 

 whole plant is sprinkled with minute glandular dots; but 

 even with the surface, and more obvious with a moderate 

 than a higher magnifier; probably the seat of its very acrid 

 property. Mr. Curtis adds, that these little cells or glands 

 are more particularly observable on the calix, which is accord- 

 ingly more biting than any other part of the plant. From 

 its hot acrid taste it has the names of Hydropipcr, Water 

 Pepper, and Arsesmart. Withering observes, that the whole 

 plant has an exceeding hot biting taste. It cures those little 

 ulcers in the mouth commonly called the thrush ; and the dis- 

 tilled water, drank to the quantity of a pint or more in a day, 

 has been found serviceable in the gravel and stone. It is a 

 diuretic of considerable efficacy, and has frequently been 

 administered with success in the jaundice, and the beginning 

 of dropsies. The expressed juice of the fresh-gathered plant 

 appears to be the best preparation of it, and may be taken 

 with safety to the amount of two or three ounces for a dose. 

 This is the only Persicaria that has any pretensions to be an 

 active medicine. When given in infusion or decoction, it 

 proves diuretic, and hence is used in the dropsy and jaun- 

 dice. The distilled water is recommended by Boyle in the 



stone and gravel. The ashes of this plant, mixed with soft 

 soap, is a nostrum for dissolving the stone in the bladder; 

 but it may be reasonably questioned whether it has any ad- 

 vantage over other semicaustic preparations of the vegetable 

 alkali. Its acrimony rises in distillation ; and the distilled 

 water, drank to the amount of two or three half-pints daily, 

 has been found very effectual in some gravelly cases. Lin- 

 neus observes, that this plant will dye woollen cloth of a 

 yellow colour; and that all domestic quadrupeds reject it. 

 Native of most parts of Europe, and found in great 

 abundance on places that lie under water during the winter, 

 flowering in September, a month later than the thirteenth 

 species ; from which it differs in its leaves of a yellower hue, 

 its slenderer spikes, and larger, more acuminate, and chestnut- 

 colonred seeds. 



11. Polygonum Persicaria; Spotted Persicaria, or Dead 

 A rsesmart. Flowers hexandrous, semidigynous ; spikes ovate- 

 oblong, erect; peduncles even; stipules ciliate. Hoot simple, 

 fibrous; stem upright, sometimes rooting at bottom, two feet, 

 or from two to three feet high, alternately branched, round, 

 smooth, gradually thickened above the joints, often red. 

 Each leaf is usually marked with a central, black, or kidney- 

 shaped spot, the under side spotted with glands, and some- 

 times white and downy. This is very nearly allied to the 

 sixth species, but the style is divided only half way down, 

 mostly into two parts, and then the germen is a little convex 

 on. each side; but sometimes into three parts, and then the 

 germen is always triangular. It may be distinguished from 

 the preceding species, which are upright, of an ovate shape 

 more or less round. Its taste is slightly astringent. Woollen 

 cloth dipped in a solution of alum, obtains a yellow colour 

 from this plant. Goats, sheep, and horses, eat it; cows 

 and swine refuse it. Common in ditches and marshes in 

 most parts of Europe ; flowering from July to September. 



12. Polygonum Minus; Small Creeping Persicaria. Flow- 

 ers hexandrous, submonogynous ; leaves linear-lanceolate, 

 flat; spikes filiform, almost erect; stem rooting at the base. 

 This, which Mr. Curtis has ascertained to be a distinct spe- 

 cies, and not a variety of the preceding, as Linneus supposed, 

 is very abundant in the watery parts of Tothill-fields, West- 

 minster; flowering in September. It has also been found 

 on Putney common ; in a gravel pit on Malvern-chase in 

 Worcestershire, and on Costesy common, near Norwich. 



13. Polygonum Barbatum ; Bearded Polygonum. Flow- 

 ers hexandrous, trigynous; spikes rod-like; stipules truncate, 

 setaceous, ciliate; leaves ciliate, lanceolate; stem herba- 

 ceous, rufous. Thunberg describes three varieties, all which 

 he found in the ditches and swampy parts of Japan. The 

 species he observed at the Cape of Good Hope, Ceylon, 

 and Java. 



14. Polygonum Tinctorium; Dyers Polygonum. Flowers 

 hcxandrous, trigynous; spikes rod-like; stipules smooth, 

 contracted, truncate, ciliate; leaves ovate, sharpish, smooth; 

 stem herbaceous, perennial, round, two feet high, manifold, 

 nearly erect. Native of China, near Canton. The Chinese 

 use it to dye abeautiful blue or green colour; and the Japa- 

 nese cultivate the thirteenth, eighteenth, and twenty-fourth 

 species, for the same purpose. 



15. Polygonum Orientale; Oriental or Garden Persicaria. 

 Flowers heptandrous, digynous ; leaves ovate ; stem erect ; 

 stipules rough-haired, salver-shaped; root composed of many 

 strong fibres, growing in tufts. Stem round, five or six feet 

 high; leaves large, downy, and flaccid, flower-stalks panicled, 

 hairy, laden with thick, obtuse, cylindrical, drooping spikes 

 of beautiful crimson flowers. The stipules are deserving of 

 notice, being unusual in their form, and making the stem look 



