Obdbe 102.— POLTGONACE^. 605 



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

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

 May. J 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. RU'fflEX, 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-angled, embryo lateral. — 

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



JLAPATHUM. 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-coroUite valves Nos. 1, 2 



a Pedicels in fruit twice longer than roxcnded or truTlcaie 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, 6 



b -Leaves wavy, the lower cordate or subcordate Nos, 7, 8 



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



5 ACETOSA. Flowers diceceous.' Valves grainless. Leaves acid (hastate) Nos.l2, 13 



1 R. crispus L. Yellow Doce. 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, 

 ahout 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 mapy racemes of half-whorls, interspersed with leaves. 

 Pedicels 3 to 4" long. Calyx-valves each with a grain on the back. Jn. § Bur. 

 — The root is used in medicine for cutaneous diseases. 



2 R. verticill^tuB L. Watek Dock. Lvs. oblong-lanceolate, acute at each end ; 

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

 close whorls; pedicels elongated, thickened, upwards. — y An aquatic species of 

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

 few branches. Lvs. long, narrow, aeute, flat. "Whorls 10 to 30-flowered. Pedi- 

 cels 1 to 10" long, deflexed. Jn. (E. Brittanious L. ? fide Gray.) 



3 R. Hydrolap^thum Hudson. /3. Ambeioana Gray. Great "Water Dock. 

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

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

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

 If. 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. aquations Smith,) 



4 R, Floridkntis Meisn. JJvs. long-lanceolate, acute and unequally narrowed at 

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

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

 grain-bearing. — Pla. (Rugel apud Meisner.) Pedicels 3 to 5" long. 



5 R. altissimuB. Pbaoh-leaved Dock. Glabrous, tall, erect; lvs. Jlat, thick, 

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

 somewhat secund, leafless or the lowest verticil aiiUary ; fls. all ^ ; valves larger, 

 broadrcordate, one graniferous, one abortively so, and the third naked. — 2f Marshy 

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

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

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

 than the valves. Jn. 



6 R, salicif61ius "Weinm. fl. Biobl6vii. Pale Dock. Jjvs. thin, wavy 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 the fruitmg calyx ; valves ail grain-bearing, ovate-oblong, scarcely longer than 

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

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



7 R. conglomer^tua Murr. Lvs. ovate or oblong, base rounded or cordate, the 

 upper lanceolate, atteuuate-acuts at eaeh eud, margins crispate ; panicle somewhat 



