POLYGONACE^.. (BUCKWHEAT FAMILY.) 419 



2. PAGOPYRUM, Tourn. BucKwriEAx. 



Calyx petal-like, equally 5-parte(l, withering and nearly unehangcd in fruit. 

 Stamens 8. Styles 3 : stigmas capitate. Achenium 3-si(lc(l, longer than tho 

 calyx. Embryo large, in the centre of the albumen, wiiich it divides into 2 parts, 

 with very broad and ibliaceous plaited and twisted cotyledons. — Annuals, with 

 triangular-heart-shaped or halberd-shaped leaves, scmicylindrieal sheaths, and 

 Cf"-vymbose racemes or panicles of white llowers, often tinged with green or rose- 

 color. (Name, (prjyos, the beech, and nvpos, wheat, from the shape of the grain 

 being that of the beech-nut ; whence also the English name Buckwheat, from 

 the German iSurfjf, lieech.) 



1. P. ESCULilNTU.M, Mocncli. (BucKwnEAT.) Smootliisli ; flower with 8 

 honey-bearing yellow-glands interposed between the stamens ; the fruit acute 

 and entire. (Polygonum Eagopyrum, Z.) — Old fields, remaining as a weed 

 after cultivation, and escaping into copses. June- Sept. (Adv. from Eu.) 



3. OXYRIA, Hill. Mountain Sorrel. 



Calyx herbaceous, of 4 sepals ; the two outer smaller and spreading, the two 

 inner broader and erect (but unchanged) in fruit. Stamens 6. Stigmas 2, ses- 

 sile, tufted. Achenium lenticular, thin, flat, much larger than llae calyx, sur- 

 rounded by a broad and veiny wing. Seed flattened in the opposite direction 

 from the wing. Embryo straight, occupying the centre of the albumen, slender. 

 — Low alpine perennia's, with round-kidney-form and long-petioled leaves 

 chiefly from the root, obliquely truncate sheaths, and small greenish flowers 

 clustered in panicled racemes on a slender scape. (Name from o^vs, sour, in 

 allusion to the acid leaves, like those of Sorrel.) 



1 . O. digyna, Campdera. Leaves all i-ound-kidney-forni, usually notched 

 at the end; fruit orbicular. — Alpine region of the White Mountains, New 

 Hampshire, Oakcs, &c., and high northward. (Eu.) 



4. RtlMEX, L. Dock. Sorrel. 



Calyx of 6 sepals ; the 3 outer herbaceous, sometimes united at the base, 

 spreading in fruit ; the 3 inner larger, somewhat colored, increasing after flow- 

 ering and convergent over the 3-angled achenium, veiny, often bearing a grain- 

 like tubercle on the back (in fruit called valves). Stamens 6. Styles 3: 

 stigmas tufted. Embryo slightly curved, lying along one side of the albumen, 

 slender. — Coarse herbs, with small and homely (mostly green) flowers, which 

 are crowded and commonly whorled in panicled racemes ; the ])ctiolcs somewhat 

 sheathing at the base. (The ancient Latin name of these plants ; of unknown 

 etymology.) 



§ 1. Dock. Fhncers perfct or nwiacioiisli/ poli/ijamoits : lierliotjr not sour: none 



of the liavfs hulbenf -shaped. {Flotariii;/ through the suvimei.) 



* Pereuiiiuls, 2° - 7° higli : ra/res not bearbiy bristles. 



•*- Valvis (larrje, 3" broad, thin) all ntdad or one with a small grain. 



1. R. Patiextia, L. (Patience Dock.) A very tall si)ccies, with ovate- 

 oblong and lanceolate leaves, those from the root 2° -3"^ long, and one of the 



