ORDER 102. POLYGONACE^E. 605 



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 the 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, conmvent over the acheniurn, 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 

 penieillate-fringed ; achenium and seed 3-angled, embryo lateral. 

 Weed-like herbs with small, greenish fls. in racemes or panicles. 



5 LAPATIIUM. Flowers all or mostly perfect. Valves 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 Pedicels in fruit twice longer than rounded or truncate valves Nos. 3, 4 



a Pedicels in fruit shorter or not longer than the valves, (b) 



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



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



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



ACETOSA. Flowers dioecious. Valves grainlcss. Leaves acid (hastate) Nos.12, 13 



1 R. crispus L. YELLOW DOCK. Lvs. lanceolate, waved, acute, the lower oblong, 

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

 bearing a grain. y Can. and U. S. A weed too common in cultivated grounds, 

 about rubbish, etc., much to the annoyance of the farmer. Stem 2 3f high, 

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

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

 Pedicels 3 to 4'' long. Calyx-valves each with a grain on the back. Jn. Eur. 

 The root is used in merlicine for cutaneous diseases. 



2 R. verticillatus L. \.~ATER DOCK. Lvs. oblong-lanceolate, acute at each end; 

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

 close whorls; pedicels elongated, thickened, upwards. U 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. Whorls 10 to 30-flowered. Pedi- 

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



3 R. Hydrolapathum Hudson. (3. AMERICANA Gray. GREAT WATER DOCK. 

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

 late-crenulate, all acute or attenuate at base, petiolate ; panicle compound, at length 

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

 i| Northern U. S. Ponds and ditches. St. 3 to 5f high. Lvs. somewhat glau- 

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

 cels in fruit 5 to 6" long, twice longer than the calyx. (R. aquaticus Smith.) 



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

 both ends, flat ; panicle, leafless above, racemes at length dense ; pedicels twice 

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

 grain-bearing. Fla. (Rugel apud Mcisner.) Pedicels 3 to 5" long. 



5 R. altissimus. PEACH-LEAVED DOCK. Glabrous, tall, erect: Ivs. flat, thick, 

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

 somewhat 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 reflexed, not longer 

 than the valves. Jn. 



6 R. salicifolius Weinm. ,3. BIGELOVIL PALE DOCK. Lvs. thin, wavy at 

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

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

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

 the grains. Sea coast, Mass, and Can. Sts. terete, slightly furrowed, 2 to 3t' 

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



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

 upper lanceolate, attenuate-acute at each cud, margins crispate : pznick somewhat 



