POLYGONACE^. 



s.:7 



1 t Valves toothed. 



G. R- acu'tus. 



Icwrf^oblono-.cordate, acuminate; ichorls leafy ; w/rw oblon<T. subdentate, 

 all of them beaming granules. Ditches and waste places. Stem 2—3 feet 

 hitrh Leaves laroe, the lower ones distinctly cordate, on long petioles. 

 Racemes paniculat'e, composed of dense, leafy, dimidiate verlicels. Granules 

 lai-ge, red, one upon the back of each valve. May. Introduced. Dock. 



7. P. pa'llidus. Etc. 



Leaves linear-lanceolate, acute ; spikes slender; valves ovate, entire, hardly 

 Uro-er than the granule. Found in salt marshes, Ms. Stems numerous, 

 ascendino-. Leaves smooth, acute, petioled, wavy on tJie margin. Flowers 

 crowded,°on short pedicels. Granule large, white, nearly covering the back 

 of each valve. June. Per. W late Dock. 



8. R. obtusifo'lius. 



S/Mftrouo-hish; radicalleaves ovate, obtuse; valves iooihed, one of them 

 principally°bearing a granule on the back. A weed as troublesome as the 

 first, growing about houses and fields wherever it is least welcome. Stem 



2 3 feet hiffii, furrowed, branching, leafy. Leaves oblong, cordate, obtuse, 



crenate-wavl' ; upper ones narrower and more acute ; root leaves very large, 

 oblono- heart-shaped, often with stalk and veins red. Flowers in long, nearly 

 nakedracemes. July. Fer. Introduced. Bioad-lcaccd Duck. 



* * Flowers dioecious. Valves without granules. Acetosa. 



9. R. acetose'lla. 



Leaves lanceolate-hastate ; floicers dioecious. A common weed, growing in 

 pastures and waste grounds throughout the U. S., preferring dry, hard soils. 



Stem a 1 foot high, leafy. Leaves halbert-shaped, very acid, but pleasant 



to the'taste. Flowering all summer. Flowers small, red or reddish, collected 

 in panicled racemes, the valves destitute of granules The stamens and styles 

 are on sepaiate plants. Per. i^idd Sorrd. Sheep Sorrel. 



• 3. RHEUM. 



Calyx colored, 6-sepaled, persistent ; stamens 9 ; styles 3; 

 stigma"^s multifid, reflexed; achenia 3-angled, llie angles mar- 

 gined. 



The name comes from Rha, the ancient name of the river Volga, on the 

 banks of which it was first discovered. Herbs. Fls. fascicled, in racemose 

 panicles. 



R. Riiapo'kticum. — Leaves smooth, cordate-ovate, obtuse ; petioles 

 channeled above, rounded at the edges. Native of Asia, cultivated in gardens 

 for the sake of the juicv, acid petioles. These are taken in a green state, in 

 the spring of the year, "and made into tarts and pies, whose excellence is well 

 known to every one. Stem stout and fleshy, 3 — 4 feet high, hollow, with 

 large, sheathing stipules at the joints. Leaves very large, 1— '2 ii?et long, § 

 as wide, on petioles of nearly the same length. Panicle terminal, at first 

 enclosed in a white, membranous bract which at length bursts, disclosing 

 innumerable o-reenish white flowers. May. Per. Garden Rhubarh or Pie-plwjLt. 



