Ordeb 102.— POLYGONACE^E. 005 



nearly the same length. Panicle terminal, at first enclosed in a white, membran- 

 ous bract which at length bursts, disclosing innumerable greenish-white flowers. 

 May. \ Siberia. — The large juicy petioles are well-known to tho pastry cook. 

 Their agreeable acidity is due to the presence of oxalate of lime. 



4. RITMEX, L. Dock. Sorrel. Calyx of 6 sepals nearly distinct, 

 the 3 inner (valves) larger, petaloid, connivent over the achenium, 1 or 

 more of them usually bearing a tubercle or grain on the back, the 3 

 outer herbaceous, reflexed in fruit ; stamens 6 ; styles 3, short ; stigmas 

 penicillate-fringed ; achenium and seed 3-angletl, embryo lateral. — 

 Weed-like herbs with small, greenish lis. in racemes or pauicles. 



§ LAl'.YTIIU.M. Flowers .ill or mostly perfect. Talves bearing grains on the back. (*) 



* Valves entire or merely angular, (a) 



a Pedicels in fruit 2 to 5 times longer than the sub-cordate valves Nos. 1, 2 



a Pedieels in fruit twice longer than founded or truncate valves JSoS. 3, 4 



a Pedieels in fruit shorter or not longer than tho valves, (b) 



b Leaves flat, all tapering to both ends Nos. 5, C 



b Leaves wavy, the lower cordate or subcordale Nos. 7, S 



* Valves conspicuously toothed on each side near the base Nos. 9 — 11 



§ ACETOSA. Flowers diceceous. Valves grainless. Leaves acid (.hastate) Nos.l'J, 18 



1 R. crispus L. Yellow Dock. Lvs. lanceolate, waved, acute, the lower ollong, 

 subcordate; pedicels twico longer than calyx ; valves broad-ovate, cordate, each 

 beariug a grain. — 1C Can. and U. S. A weed too common in cultivated grounds, 

 about rubbish, etc., much to tho annoyance of the farmer. Stem 2 — of high, 

 smooth, channeled, from a yellow, fusiform root. Flowers numerous, in a largo 

 panicle, consisting of many racemes of half-whorls, interspersed with leaves. 

 Pedicels 3 to 4'' long. Calyx-valves each with a grain on tho back. Ju. § Eur. 

 — Tho root is used in medicine for cutaneous diseases. 



2 R. vcrticillatu3 L. Water Dock. Lvs. ohlong-lanceolate, acute at each end ; 

 valvc3 entire, broad-ovate, each bearing a grain ; rac. leafless, with flowers in 

 clo 50 whorls ; pedicels elongated, thickened, iqnuards. — If An aquatic species of 

 muddy situations. Can. and U. S. St. 2f high, with long, tubular sheaths and 

 few branches. Lvs. long, narrow, acute, flat. Wborl3 10 to 30-ilowered. Pedi- 

 cels 7 to 10" long, deflexed. Ju. (R. Brittanicus L. ? fide Gray.) 



3 R Hydrolapathum Hudson. /?. Americana Gra}-. Great Water Dock. 

 Lvs. lanceolate, acuminate, lower lance-oblong, very long, upper minutely undu- 

 lale-crenulatc, all acute or attenuate at base, petiolate ; panicle compound, at length 

 naked; verticils at first distinct; valves roundish-ovate, obtuse, all grain-bearing. — 

 If Northern U. S. Ponds and ditches. St. 3 to 5f high. Lvs. somewhat plati- 

 ceus, lower very largo, 1 to 2f long, 2 to 5' wide, with a stout midvein. Pedi- 

 cels in fruit 5 to G" long, twice longer than tho calyx. (R. aquation Smith.) 



4 R. Floridarru.3 Meisn. Lvs. long-lanceolate, acuto and unequally narrowed at 

 "both ends, flat ; panicle, leafless above, racemes at length denso ; podieels twico 

 longer than the fruiting calyx ; valves broadly ovate-deltoid, bluntly acuminate, all 

 grain-bearing. — Fla. (Rugel apud Meisner.) Pedicela 3 to 5'' long. 



5 R. altf ssirnus. Peach-leaved Dock. Glabrous, tall, erect : lvs. flat, thick, 

 linear-elliptic, entire, petiolate, tapering to each end; rac. slender, paniculate, 

 Bomewhat secund, leafless or the lowest verticil axillary; fls. all £ ; valves larger, 

 broad-cordate., one graniferous, one abortively so, and the third naked. — If Marshy 

 prairies and borders of streams, Mid. and W. States. A very showy Rumex, 

 3 — 6f high, slightly branched above. Leaves 3 — 5' by \ — 1', somewhat acumi- 

 nate, broadest in the middle. Verticils approximate, pedicels reflcxed, not longer 

 than tho valves. Jn. 



6 R. salicifolius Weinm. (i. Bigklovii. Pale Dock. Lvs. iliin, wary at 

 edge, attenuate-acute at each end, linear-lanceolate, petiolate ; panicle simple, 

 leafy at base, racemes spicate, loose and interrupted below ; pedicels much shorter 

 than tho fruiting calyx ; valves all grain-bearing, ovate-oblong, scarcely longer than 

 the grains. — Sea coast, Mass. and Can. Sts. terete, slightly furrowed, 2 to 3/ 

 high. Lvs. 4 to 7' long. Grainy unequal, large, white. Jn. (R. pallidus Bw.) 



7 R. conglomerates Murr. Lvs. ovate or oblong, base rounded or cordate, the 

 upper lanceolate, attenuatc-acnta at each cud, margins crispato ; panicle somewhat 



