POLYGOXACE^. (BUCKWHEAT FAMILY.) 407 



Suborder III. EKIOGONE^. Flowers surrounded by an involucre. 

 Calyx 6-parted. Stamens 9. Ovule sessile. Embryo included in scarce albu- 

 men. Stipules none. 

 7. ERIOGONUM. Involucre 5-toothed. Woolly or silky herbs. 



1. RUMEX, L. Dock. 



Flowers perfect or dia'cious. Calyx herbaceous, 6-parted, the 3 outer lobes 

 spreading or recurved, tlie inner ones (valves) mostly enlarged in fruit, and 

 euclusiiig the 3-augled achenium, often bearing grain-like prominences on the 

 outside. Stamens 6 : autliers erect. Styles 3 : stigmas many-cleft. Ache- 

 nium 3-angled. Embryo curved on tlie outside of the albumen. — Herbs, 

 with alternate leaves, smooth truncated sheaths, and small green flowers iu 

 racemed or jjanicled clusters. 



* Flowers perfect or polyfjamous. 

 •I- Valves etttire. 



1. R. erispus, L. Smooth; leaves lanceolate, Avavy-crisped, acute at 

 both ends, or the lowest truncate or slightly cordate at the base, and long- 

 petioled, the uppermost linear; panicle leafy at the base; wliorls crowded 

 in fruit ; valves broadly cordate, obtuse, one or all graiu-bearing. — Waste 

 ground around dwellings. June -July. 5/ — Stem 2° -3° high. Lowest 

 leaves 1° long. 



2. R. vertieillatus, L. Smootli ; lowest leaves oblong, obtuse or cor- 

 date at tlie base, flat, the others lanceolate, acute at each end ; panicle naked, 

 loose-flowered ; pedicels slender, thickened upward, reflexed in fruit ; valves 

 ovate, obtuse, rugose-veined, each bearing a large grain, half as wide as the 

 valve. — Swamps and ditches, Florida, and northward. May -June. ^ — 

 Stem 1°- 2'^ high. Lowest leaves 1° - H° long. 



3. R. Floridanus, Meisner. Smooth; stem stout, branching; leaves 

 lanceolate, acute at each end ; panicle naked, dense-flowered ; pedicels about 

 twice as long as the valves, thickened upward, reflexed in fruit ; valves del- 

 toid-ovate, obtusely pointed, each bearing a narrow grain, which is much nar- 

 rower than the reticulate valve, — Deep river swamps, Florida, and west- 

 ward. June. 2/ — Stem 2° - 3° high. Leaves i° - li° long. 



4. R. sanguineus, L. Lowest leaves oblong, cordate, acute or obtuse, 

 the upper lanceolate, wavy-margined ; panicle leafless ; lower whorls distant ; 

 valves ol)long, longer than the pedicel, one only prominently grain-bearing. — 

 Waste ground. Introduced. June -July. ^ — Stem 2° - 3° high. Lowest 

 leaves large, variegated with red veins. 



•»- -f- Valves toothed or hristly on the margins. 



5. R. obtusifolius, L. Stem ronghish ; lowest leaves large, ovate-ob- 

 long, cordate, mostly obtuse, the uppermost lanceolate, acute at each end ; 

 panicle large, leafy below; lowest whorls scattered, the upper somewhat 

 crowded ; valves triangular-ovate, toothed near the base, nearly as long as the 

 sleniler recurved pedicels, one or all more or less prominently grain-bearing. 

 — Waste ground. Introduced. June -Aug. 11 — Stem 2° -3° high. Lowest 

 leaves 1°-1J° long. 



