Polygonum Hydropiper. Biting Persicaria or 



Water Pepper. 



POLYGONUM Linnai Gen. PL Octandria Trigynia. 



Cal. o. Cor. 5-partita, calycina. Sent. 1, angulatum. 



Ral Syn. Gen. Herbje flore imperfecto seu Stamineo vel apetalo potius. 

 POLYGONUM Hydropiper floribus hexandris femidigynis ; foliis lanceolatis, undulatis, immaculatis ; 



fpicis filiformibus nutantibus. 

 POLYGONUM Hydropiper floribus hexandris femidigynis, foliis lariceolatis, ftipulis fubmuticis. Linn. 



Syfi. Vegetab. p. 312. 

 POLYGONUM foliis ovato lanceolatis, fpicis florigeris, vaginis calvis. Hatter, hlft. p. 256. n. 1 554* 

 POLYGONUM Hydropiper. Scopoll FL Carnlol. n. 467. 

 PERSICARIA urens feu Hydropiper. Bauhln. pin. 10 1. 

 PERSICARIA vulgaris acris feu minor. Parkin/on. 856. 



HYDROPIPER. Gerard, emac. 445. Rail Syn. p. 144. Water-pepper, Lakeweed or Arfmart. Hudjbtr 

 FL Angl. p. 148. 



RADIX annua, fibrofa. 



CAULIS erectus, ramofus, bail nonnunquam repens, 

 pedalis ad tripedalem, geniculis incraifatis, de- 

 mum ruberrimus. 



FOLIA lanceolata, undulata, e viridi flavefcentia, glabra. 



STIPULE ciliata?. 



FLORES fpicati, fpica tenues, demum nutantes. 



CALYX : Perianthium quadripartitum, glandulls mi- 

 nimis adfiperfium, laciniis obtufis, concavis, Jig. 

 1 ' 2 5« 



COROLLA nulla. 



STAMINA : Filamenta fex alba ; Anthers albae 

 biloculares, jig. 3. 



PISTILLUM: Germen ovatum; Stylus bifidus, ad 

 medium ufque divifus ; Stigmata duo, ro- 

 tunda, fig. 4, 5. 



SEMEN ovato-acuminatum, caftaneum, fig. 6. 



ROOT annual and fibrous. 



STALK upright, branched, fometimes creeping at bot- 

 tom, from one to three feet high, the joints 

 fwelled, finally becoming very red. 



LEAVES lanceolate, waved, of a yellow iih green colour 

 and fmooth. 



STIPULE ciliated. 



FLOWERS growing in fpikes, which are Jlender and 

 finally drooping. 



CALYX : a Perianthium divided into four fegments, 

 fiprlnkled with very minute glands, the fegments 

 blunt and hollow, fig. 1, 2, 3. 



COROLLA wanting 



STAMINA fix white Filaments; Anthers white 

 and bilocular, fig. 3. 



PISTILLUM: Germen oval; Style bifid, divided 

 down to the middle; two round Stigmata, 



fg- 4, 5- 

 SEEDS of an oval pointed fliape, and chefnut- colour, 



fg- 6. 



It is one of the maxims laid down by the Author of that fyftem of Botany which at prefent is fo defervedly held 

 in efteem, and which I trufr. for the fake of this delightful fcience will for ever withftand the attempts of all thofe 

 who frame fyftems merely to raife themfelves into confequence, that in all fpecific defcriptions tafte is to be ex- 

 cluded : fome may perhaps be ready to treat this as too dogmatical, but when they come to find that both the 

 Hydropiper and Sedum acre, plants which in general are very hot and biting, fometimes are found infipid, they will 

 readily adopt it as founded in ftrict propriety. 



The prefent fpecies of Polygonum very properly receives its name of Hyaroplper from its hot and biting tafte, 

 which appears to arife from its eflential oil difperfed in little cells or glands all over the plant, but more particularly 

 obfervable on the Calyx with a fmall magnifier, and which, if tailed, will be found to be more biting than any 

 other part of the plant : this quality which is peculiar to the Hydropiper, generally leaves a ftrong Idea of the plant 

 on the mind of the Tyro : but it is has other more invariable characters whereby it maybe diftinguifhed. Notwith- 

 standing its obvious difference from the other plants of this genus, apparent even to fuch as know very little of 

 Botany, both Scopoli and Haller feem to entertain doubts whether it be really diftincl: from the P. Perficaria 

 and P. minus. 



The three plants as they ufually grow, and I have feen them all three grow together, are certainly diftincT: enough : 

 but there are fome intermediate varieties which bring them very near together, and perhaps juitify fuch fufpicions : 

 a variety of the Hydropiper, fcarce differing in any other refpecl: but its infipidity, I have now and then met with 

 in the fame fituation as we ufually find the true fpecies : from the P. Perficaria it differs principally in its leaves, 

 fpikes, form and fize of its feeds ; and firfr. its leaves are of a yellower hue, more undulated, and never marked with 

 any fpots ; its fpikes are (lender, and when the feeds are ripe they bend and hang down ; the feeds are much larger, 

 more acuminated, and of a chefnut colour; its ftipuhe are very evidently ciliated ; though Haller makes their 

 want of ciliae one of its ftriking characters; and Linnjeus alfo calls them fiubmutica, which certainly tends to 

 miflead. 



It is the only Perficaria that has any pretenfions to be an active medicine : given in infufion or decoction it proves 

 diuretic, hence it is made ufe of in the Dropfy and Jaundice; and the diftilled water of it is recommended by Boyle 

 as efficacious in the Stone and Gravel: Linnaeus informs us that the plant will dye Woolen cloth of a yel- 

 low colour. 



Although the herb is fo acrid, the feeds are infipid and nutritive. 



It is found in great abundance in all thofe places which lie under water during the Winter, flowers in Sep- 

 tember, generally a month later than the P. Perficaria : in expofed places it becomes very red in going off. 



