Rumex.] LXIII. POLYGONACEJE. 383 



or sometimes monoecious, in long, terminal, leafless panicles, usually 

 turning red. Inner segments of the fruiting perianth enlarged, orbicular, 

 thin and almost petal-like, quite entire, without any tubercle, but each 

 with a minute scale-like appendage at the base, which, as well as the 

 small outer segments, is turned back on the pedicel. 



In meadows and moist pastures, in Europe, central and Kussian Asia, 

 in northern America, from the Mediterranean to the Arctic Circle, 

 ascending high into mountain-ranges, and reappearing in the southern 

 hemisphere. Extends all over Britain, and has long been in cultivation. 

 Fl. summer, 



10. R. Acetosella, Linn. (fig. 867). Sheep-sorrel. — A slender plant, 

 from 3 or 4 inches to nearly a foot high, acid like R. Acetosa, and often 

 turning red. Leaves all narrow-lanceolate and linear, and some at least 

 of every plant sagittate, the lobes of the base usually spreading and 

 often divided. Flowers small, dioecious, in slender terminal panicles. 

 Segments of the perianth small, broadly ovate or orbicular, entire, and 

 thin ; the inner ones closing over the nut as in the other species, but 

 scarcely enlarged ; the outer ones erect, not reflexed as in R. Acetosa. 



In pastures, especially in dry open places, over the greater part of 

 the globe without the tropics, penetrating far into the Arctic regions, 

 and ascending high upon alpine summits. Abundant in Britain. Fl. 

 from spring tUl autumn. 



II. OXYRIA. OXYKIA. 



A single species, with the habit of a small Rumex of the Acetosa group, 

 separated from that genus because the perianth has only 2 inner and 2 

 outer segments of the perianth, and the ovary has only 2 stigmas. 



1. O. reniformis, Campd. (fig. 868). Kidney Sorrel. — A glabrous 

 perennial, seldom above 6 inches high, of an acid flavour. Leaves 

 chiefly radical, cordate-orbicular or kidney-shaped, usually less than 

 half an inch, but sometimes an inch broad. Stem slender and almost 

 leafless, terminating in a simple or slightly branched raceme. Flowers 

 small, in clusters of 2 or 3, on slender pedicels ; the inner segments of 

 the perianth slightly enlarged, but shorter than the nut. Stamens 6. 

 Nut flat, orbicular, about 2 lines in diameter, including a scarious wing, 

 which surrounds it, and is entire or notched at the top and base. 0. 

 digyna, Hill. 



A high alpine plant, in all the great mountain-ranges of Europe and 

 Asia, descending to a lower level in the north, and extending far into 

 the Arctic regions. Frequent in the mountains of Scotland, northern 

 England, and North Wales ; rare in Ireland. Fl. summer. 



III. POLYGONUM. POLYGONUM. 

 Herbs, varying much in habit, but not so stiffly erect as the Docks, 

 and sometimes prostrate, floating, or twining ; the scarious stipules 

 usually sheathing the stem, and often fringed at the edge ; the leaves 

 alternate. Flowers small, pale-green or red, clustered or rarely solitary 

 in the axils of the upper leaves, or in terminal heads, spikes, or panicles. 

 Perianth of 5 (rarely fewer) segments, either all equaJ or 2 or 3 outer 



