Polygonum Pensylvanicum. Pale - flowered 



Persicaria. 



POLYGONUM Unnai Gen. PL Octandria Trigynia. 



RaiiSyn. Gen. 5. Herb;eflore imperfecto seu Stamineo(vel apetala potius,) 

 POLYGONUM floribus hexandri?, digynis; flipulis muticis ; pedunculis fcabris ; feminibus utrinque 



depreffis. 

 POLYGONUM floribus o&andris digynis, pedunculis hifpidis, foliis lanceolatis, flipulis muticis. 



Linnxi Syjl. Vegetal. Sp. Plant, p. 519. 

 PERSICARIA mitis major foliis pallidioribus. D. Bobarti, Dead Arfmart the greater with pah leaves. 

 Rail Syn. ed. 3./. 145. Hud/on Fl. Angl. p. 148. 



RADIX fibrofa, annua. 



CAULIS tripedalis circiter, teres, glaber, fiftulofus, 



ramofus ; rami patentes, geniculis maxime in- 



craffatis. 

 FOLIA ovato-lanceolata, fupra glabra, fubtus glandulis 



punctata, fiepe pubefcentia, ciliata, nunc ma- 



culata nunc immaculata. 



PETIOLI fubtus hirfuti, fcabriufculi. 

 STIPULE bafi nervofe, muticae. 



PEDUNCULI pilis brevibus glanduliferis fcabri.j%\ 1. y 



FLORES herbacei, pedunculis brevibus infidentes, denfe 

 glomerati, fpicae ovatas, feminibus maturis fub- 



uutantes. 



laciniis o- 



CALYX : PeriANTHIUM qumquepartitum 



vatis, obtuiis, fig. 2, 3. 

 COROLLA nulla. 

 STAMINA: Filamenta fex, fubulata, alba, Corolla 



paulo breviora ; Anthers biloculares ; Pol- 

 len globofum, Jig. 4. 

 PISTILLUM : Germen fubovatum ; Stylus fere ad 



bafin diviius ; Stigmata duo fubrotunda, 



Jig, 5, 6. 

 SEMEN cordatum, acuminatum, comprefTum, medio 



deprefium, nitidum, Jig. 9, 10, magnit. nzt.jig. 



7, 8, lente audi, fubinde obtufe triquetrum, 



* 



ROOT fibrous and annual. 



STALK about three feet high, round, fmooth, hollow* 



branched, the branches fpreading, and the 



joints very much fwelled. 

 LEAVES of an oval pointed fhape, fmooth on their 



upper furface, underneath dotted with fmall 



glands, and often downy, edged with little 



hairs, fometimes with and fometimes without 



fpots. 

 FOOT-STALKS of the leaves hairy underneath, with 



a flight roughnefs to the touch. 

 STIPUL/E rib'd at bottom, and not terminated by any 



hairs. 

 FOOT-STALKS of the flowers rough with little glands. 



fig- 1. 



FLOWERS of a greenifh colour, fitting on fhort foot- 

 stalks, and growing thickly together ; fpikes 

 oval, and when the feeds are ripe drooping 

 a little. 



CALYX: aPERiANTHiUM divided into five fegments, 

 which are oval and obtufe, fg. 2, 3. 



COROLLA wanting. 



STAMINA : fix Filaments, tapering, white, a little 

 fhorter than the Corolla ; Anthers bilocular ; 

 Pollen globular, J$g\ 4. 



PISTILLUM: Germen fomewhat oval; Style divi- 

 ded, nearly down to the bafe ; Stigmata two, 

 roundifh, fg. 5, 6. 



SEED heart-fhaped, pointed, flat, with a deprejfion in 

 the middle, mining,^. 9, 10, of its natural 

 fize, fig. 7, 8, magnified, fometimes obtufely 

 triangular, fig. 1 2. 



it here figured, is the Perficaria mitis major foliis pallidioribus, D. Bobarti, and which is particularly 

 the 3d. edition of Ray's Synopfis, p. 145 : from the confonancy of this defcription, with that which 



The plant 

 defcribed in tr. 



Linnjeus had given of the Polygo?ium 'Penjyhanicum, in the 3d. edition of his Speices Plantarum, Mr. Hudson fet it 

 down in his Flora as that fpecies : and Linnjeus, in the kit edition of his Syfiema Vegeiab. as a confirmation of our 

 Englifn Polygonums, being the fame with his Penfylvanicum, quotes Bob arts's defcriptive name. 



By Ray^ Linnaeus, and Hudson, then, it is made a diitincl fpecies ; by Haller it is confidered as a variety 

 of the Polygonum Perficaria ; but as the Baron forms his judgment from dried fpecimens that were fent him, in which 

 many of the diftinguifhing characters of this plant would be unavoidably loft, he feems the moft likely to be miftaken : 

 I fhall therefore join in making it a diftincl fpecies ; and I truft fhall give fuch ftriking additional characters, as will 

 fettle this matter beyond difpute. 



The true Polygonum Penjyhanicum (for there are feveral varieties of it) has the greateft affinity with the Polygonum 

 Perficaria, but differs from it in the following particulars, viz. place of growth, fize, ftipulae, leaves, foot-ftalks of 

 the leaves, foot-ftalks of the flowers, ftyle, and feeds. 



While the Polygonum Perficaria ufually delights to grow by the fides of moift ditches, the Penjyhanicum prefers a 

 richer and more luxuriant foil ; and fo common is it with us about town, that there is fcarce a dunghill on which it, 

 may not be found : indeed in its attachment to this particular foil, it refembles many of the Chenopodiums or Oraches. 

 Was it never to occur in other fituations, fome might be ready to fufpect. that it was a variety of the Perficaria anfing 

 from richnefs of foil ; but it is frequently found in other places : and I remember once to have feen the Polygonum 

 Perficaria, Hydropiper, and Penjyhanicum, all growing by the fide of a ftream within fix inches of each other. 



In its moft common ftate it is much larger than the Polygonum Perficaria, and its joints in particular are more fwelled ; 

 its Stipule are much more ftrongly rib'd at bottom, and have no Cilias ; its leaves are broader, the veins fomewhat 

 deeper, and more ftrongly marked ; the hairs on the edges of the leaves more vifible, but particularly fo under the 

 foot-ftalk of the leaf, to which they give a manifeft roughnefs : in the uppermoft leaves the under fide is generally 

 dotted with very minute glands, while in the lowermoft it is covered with a kind of down : this laft character, though 

 contrary to what Linnaeus aflerts, is never feen in the Polygonum Perficaria ; but in this fpecies it is always more or 

 lefs predominant. The foot-ftalks of the flowers are thickly befet with little yellowifh glands, ftanding on _ fhort 

 foot-ftalks, which fometimes extend halfway down the plant ; this appearance never or exceeding rarely occurs in the 

 Polygonum Perficaria: the flowers are of a pale or greenifh hue, and form thicker and largerfpikes than in the Polygonum 

 Perficaria, and when ripe are fo heavy as frequently to hang down a little: the Style is divided very nearly down to 

 the Germen, while in the Polygonum Perficaria it is divided only half way ; and this divifion of the Style, I look upon 

 as one of the moft conftant and certain criteria of this fpecies : laftly the form of the feeds contributes not a little to 

 the farther afcertaining and fixing it ; in the Perficaria the feeds are either triangular, or of a pointed oval fhape, with 

 a little convexity on each fide ; in this fpecies it is in general flat, with a deprejfion on each fide ; it is alfo larger and 

 broader ; now and then a feed occurs forming an unequal triangle, but thefe are very rare, while the triangular feed 

 is moft frequent in the Polygonum Petficaria, 



