POLYGONACE^E. (BUCKWHEAT FAMILY.) 385 



SUBORDER HI. ERIOGONE^E. Flowers surrounded by an invo- 

 lucre. Calyx 6-parted. Stamens 9. Qvule sessile. Embryo included 

 in scarce albumen. Stipules none. 

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



1. BUMEX, L. DOCK. 



Flowers perfect or dioecious. Calyx herbaceous, 6-parted, the 3 outer lobes 

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

 enclosing the 3-angied achenium, often bearing grain-like prominences on the 

 outside. Stamens 6 j anthers erect. Styles 3 : stigmas many-cleft. Achenium 

 3-angled. Embryo curved on the outside of the albumen. Herbs, with alter- 

 nate leaves, smooth truncated sheaths, and small green flowers in racemed or 

 panicled clusters. 



* Flowers perfect or polygamous. 



- Valves entire. 



1. R. crispus, L. Smooth; leaves lanceolate, wavy-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 ; whorls crowded in 

 fruit ; valves broadly cordate, obtuse, one or all grain-bearing. Waste ground 

 around dwellings, Florida, and northward. June and July. }J. Stem 2 -3 

 high. Lowest leaves 1 long. 



2. R. verticillatus, L. Smooth ; lowest leaves oblong, obtuse or cordate 

 at the 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, which is half as wide as the 

 valve. (R. Britannicus, Ell.) Swamps and ditches, Florida, and northward. 

 May and June. 1J. Stem 1 - 2 high. Lowest leaves 1 - 1 long. 



3. B. 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 deltoid- 

 ovate, obtusely pointed, each bearing a narrow grain, which is much narrower 

 than the reticulate valve. Deep river-swamps, West and South Florida. June. 

 1|. Stem 2 - 3 high. Leaves - 1 long. 



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

 the upper lanceolate, acute, obtuse or cordate at the base, wavy -margined ; pan- 

 icle leafless ; lower whorls distant ; pedicels very short ; valves oblong, longer 

 than the pedicel, one only prominently grain-bearing. Around Charleston, 

 Elliott. New Berne, Croom. Introduced. June and July. 1J. Stem 2 -3 

 high. Lowest leaves large, variegated with red veins. 



*- -i- Valves toothed or bristly on the margins. 



5. R,. obtusifolius, L. Stem roughish ; lowest leaves large, ovate-oblong, 

 cordate, mostly obtuse, the middle ones oblong, 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 



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