e04 Oedee 102.— poltgonace^. 



albuminous, with a straight or curved inverted embryo. Illuat. in Figs. 80, 315, 

 4:01, 408, 409, 413, 601, 103, 112. 



Genera 83, species 600 (Meisnor) widely diffused in all lands, but most abundant in the tem- 

 perate zones. , ,, «,.,».,. 



Properti^.—The roots of these plants are nauseous and purgatiye. Jlktibarb of the shops is 

 the root of Kheum palmatum and other species, native of Tartary. But the leases and etalka 

 of Sorrel, the petioles of Garden Rhubarb, etc., are agreeably tart, and contain oxalic acid ; the 

 petioles of the latter, together with the farlnaceons seeds of the Buck-wheat, are well-known 

 articles of food. 



TRIBES AND GENEEA. 



1. EEIOGONEjE. Flowers in dense, involucrate umbels, Ochrera Ekiogontim. I 



II. POLTGONEjE. Flowers not involucrate. Oohreee present, (a)' 



a Calyx 4-parted, regular. Stamens G. Styles 2. Achenia winged Oxraii. 2 



a Calyx 6-parted. Stamens 9. Sepals all similar, short EniinM. 8 



a Calyx 6-parted. Stamens 6. Sepals 8, inner increiuslng, tubcrculate.. RuiiBX. 4 



a Calyx 5-parted (irregularly 4-parted in one species), (b) 



b Sepals, the 3 inner fimhriate-pectinate. Pedicels solitary Thtsanklla. 5 



b Sepals entire, — 3, closed on the achenia, or all open. Pedicels solitary .Polygonella, 6 

 —all closed on the aohenium. Pedicels usually fascicled. .Polyoohdm. 7 

 —all open. Nectaries 8. Pedicels fascicled in the bract. . .Fagopybdm. 8 



1. ERIOG'ONUM, Mx. (Gr. epiov, wool, yow, knee ; being woolly 

 at the joints, etc.) Flowers many in each common 6-toothed involucre ; 

 calyx deeply 5-cleft ; stamens 9 ; styles 3 ; achenia 3-angled or 3-lobed ; 

 embryo in or near the axis of scanty albumen. — Herbs clothed with 

 dense cottony wool. Lvs. alternate, exstipulate, mostly at the base of 

 the stem, the upper bract-like, often whorled at the forks of the umbel- 

 late inflorescence. Invol. solitary or capitate. Pedicels within the in- 

 vol. 1-flowered. 



1 E. tomentosum Mx. Lower lvs. crowded, spatulate, obovate or oblong,, pe- 

 tiolate, beneath rusty white, tomentous, veins tawny red ; flowering branches 

 several times forked ; invol. solitary, campauulate, sessile, 6-toothed, loose-flow- 

 ered; cal colored, funnel-form. — U Sandy hills, S. Car. to Ma., frequent. St. 1 

 to 3f high. Lvs. 2 to 3' long, those of the stem much smaller. Ks. 3 to i" long, 

 cream-white, with wool of the same color outside. Jn. Aug. 



2 E. longifolium Nutt. Lower lvs. crowded, oilong-lmear, with a long, attenu- 

 ated base, beneath white-tomentous, upper lvs. scattered ; panicle ample, sevferd 

 times forked ; bracts minute ; invol. solitary, campanulate, pedunculate many- 

 flowered ; cal green, woolly. — Fla. to Ark. St. 2 to 4f high. 



2. OXYR'IA, R. Br. Mountain Sorrel. (Gr. o^g, acid ; in allu- 

 sion to the qualities of its leaves.) Calyx herbaceous, 4-sepaled, the 2 

 inner sepals erect, larger, the 2 outer reflexed ; achenium lens-shaped, 

 thin, girt with a broad, membranous wing ; stamens 6, equal ; stigmas 



2, sessile, penicillate. — 71 Low, nearly acaulescent, alpine plants. 



O. reniformis Hook. Radical lvs. reniform, on long petioles ; outer sepals ob- 

 long, half as long as the inner, valvular sepals ; fruit orbicular. — Found on the 

 summits of the White Mts., in moist ravines; and N. to the Arc. Sea. The plant 

 is acid to the taste, like Eumex acetosus. Stem 3 — i' in height, nearly leafless, 

 racemed or subpaniculate. Jn. (Rumex digyuus L.) 



3. RHE^UM, L. Rhubarb. {Rha, the river Volga, on whose banks 

 the plants arc said to be native.) Calyx colored, 6-sepaled, persistent ; 

 stamens 9 ; styles 8, very short, spreading ; stigmas multifid, reflexed ; 

 achenia 3-angled, the angles margined. — 2C Fls, fasciculate in racepious 

 panicles. 



R. Rhap6nticum L. Gaedejj Ehubakb on Pie-plant. Lva. ample, 

 smooth, cordate-ovate, obtuse ; petioles channeled above, rounded at the edges. — 

 Gardens. Stem stout and fleshy, 3 — 4f high, hollow, with large, sheathing sti- 

 pules at the joints. Leaves very large, 1 — 2f long, f as wide, on petid|s of 



