OXYRIA. POLYGONUM. 283 



% 



leafless. Nut elliptical Ditches and river-sides. P. VII. VIII. 

 Great Water Dock. 



*11. R. alpinus (L.) ; enlarged pet. cordate-ovate membranous 

 entire or denticulate without tubercles, /. roundish-cordate blunt 

 with channeled petioles, upper 1. ovate. E. B. S. 2694. Whorls 

 crowded, mostly leafless. Nut elliptical, acute. Formerly cul- 

 tivated. P. VII. Monk's Rhubarb. E. S. 



** FL dioecious. Herbage acid. Acetosella Tourn. Sorrels. 



12. R. acetosa (L.) ; enlarged pet. roundish-cordate entire 

 membranous with a very minute tubercle at the base, sep. reflexed, 

 1. oblong sagittate, stipules laciniate-dentate. R. Pseudo-acetosa 

 Bert, .E. 5. 127? Height 12 feet. Whorls leafless. Nut el- 

 liptical with acute angles. Smith describes under this name the 

 R.hispanicus ("Hunting," Koch) which is occasionally cultivated. 

 Meadows and pastures. P. V. VI. 



13. R. Acetosella (L.) ; petals scarcely enlarged ovate not 

 tubercled, sep. ascending, 1. lanceolate-hastate or linear with en- 

 tire lobes, stipules torn. E. B. 1674. Height 6 10 in. Whorls 

 leafless. L. very variable in breadth. Dry gravelly places. P. 

 V. VII. Sheep's Sorrel. 



[R. scutatus (L.) ; 1. hastate-ovate slightly fiddleshaped ; has 

 been found " naturalized " near Edinburgh and elsewhere.] 



2. OXYRIA Hill. Mountain Sorrel. 



1. 0. reniformis (Hook.). E. B. 910. St. 810 in. high, 

 usually leafless. L. radical, reniform, slightly notched at the end, 

 with the veins radiating from the insertion of the long footstalk. 

 Pedicels thickening upwards, jointed in the middle. The per- 

 manent pet. not enlarged. Lofty mountains. P. VII. VIII. 



3. POLYGONUM Linn. 



* Stem simple, bearing one spike. Ochrece truncate. Root a 

 rhizome. Nut triquetrous. Stam. 8. Styles 3. Bistorta. 



1. P. Bistorta (L.} ; spike dense, I. ovate subcordate, root-1. 

 with winged footstalks, faces of nut ovate smooth. E. B. 509. 

 St. 1 U foot high. Root large. Fl. flesh-coloured. Moist 

 meadows. P. VI. and X. Snakeweed. 



2. P. viviparum (L.); spike lax bulbiferous bearing fl. on its 

 upper part, /. linear-lanceolate with revolute margins, lower I. 

 elliptical with wingless footstalks, faces of nut ovate-lanceolate 

 smooth and shining. E. B. 669. Height 4 8 in. Spike 

 slender, the fl. on the lower part replaced by small red bulbs. 



