Rumex.] POLYGON ACE JE. 351 



brown. Panicle with erect branches, leafless ; male whorls densely 4-8-fld. ; 

 pedicels jointed below the middle. Sepals of male fl. herbaceous, margins 

 white or pink, scarious ; of female, \ in. when in fruit, pink or crimson. 

 Fruit brown, shiuing. — Distrib. N. temp, and Arctic zones. — A salad and 

 pot-herb ; abounds in binoxalate of potasn. 



11. R. Acetosel'la, L. ; dicecious, lower leaves hastate, uppermost 

 sessile, outer fruiting sepals appressed, inner hardly enlarged oblong- 

 ovate entire herbaceous, midrib thickened at the base. Sheep's Sorrel. 

 Dry pastures, N. to Shetland, ascends to 2,500 ft. in York ; Ireland ; Channel 

 Islands ; fl. May- Aug. — Perennial, acid, glabrous, often bright red in autumn. 

 Rootstock creeping, much branched. Stems 3-20 in., often many and tufted, 

 decumbent at the base, slender. Leaves §-2 in., long-petioled, variable in 

 breadth, often 3-lobed ; stipules silvery, torn. Panicle leafless, branches 

 erect ; male flowers largest ; pedicels as long as the fruiting sepals, jointed 

 at the top, length variable. Fruiting sepals T ^ in., obtuse, closely investing 

 the yellow-brown fruit. — Distrib. N. temp, and Arctic zones; introd. into 

 theS. 



3. OXYR'IA, Hill. Mountain Sorrel. 



Characters of Rumex, but sepals 4 ; anthers versatile ; ovary com- 

 pressed ; stigmas 2 ; fruit lenticular, broadly winged, and embryo axile. — 

 Distrib. Arctic regions and Alps of the N. temp, zone ; species 1. — 

 Etym. b^vs, from the acidity of the leaves. 



O. digyna, Hill ; leaves cordate or reniform. 0. reni/or'mis, Hk. 

 Mountain rocks and streams, from N". Wales and "Westmoreland to Orkney ; 

 ascends to near 4,000 ft. ; S.W. Ireland ; fl. July-Aug. — Perennial, glabrous, 

 rather fleshy, acid. Rootstock tufted. Stem 6-18 in., stout, subsimple. 

 Leaves, radical many, |-| in. broad, long-petioled, rounded or refuse, rarely 

 3-lobed or subhastate ; cauline solitary. Panicle slender, leafless, lax-fld. ; 

 pedicels slender, jointed at the middle, top thickened. Outer sepals spreading 

 or reflexed ; inner ^ g in., spathulate, 3-5-nerved. Fruit £ in. diam. ; wing 

 orbicular-cordate, membranous, veined, top notched. — An excellent pot-herb 

 and antiscorbutic. 



Order LXI1I. aristolochiace^g. 



Herbs or shrubs, aften climbing. Leaves alternate, entire or lobed, 

 exstipulate. Flowers 2-sexual, solitary spiked or racemed, regular or 

 irregular. Perianth superior, tubular, campanulate or trumpet-shaped ; 

 limb 3-lobed or 1 -lipped, valvate in bud. Stamens 6 or 12, rarely 5 ; 

 anthers subsessile, free or adnate to the style, cells introrse or extrorse. 

 Ovary 4-6-celled ; styles 6, inner surface stigmatic ; ovules very many, 

 anatropous, 2-seriate in the inner angles of the cells. Fruit a 4-6-valvec! 

 septicidal capsule, or a berry. Seeds horizontal flattened or boat-shaped, 

 raphe thickened, albumen copious fleshy or horny ; embryo minute, 



