376 POLYGONACE^. (BUCKWHEAT FAMILY.) 



1. P. BSCULENTUM, Moench. (Buckwheat.) Smoothish; flower with 8 

 honey-bearing yellow-glands interposed between the stamens ; the fruit acute 

 and entire. (Polygonum Pagopynim, i.) — Old fields, remaining as a weed 

 where the plant has been cultivated, and escaping into copses. June -Sept. 

 (AdT. from Eu.) 



3. OXl^RIA, Hill. MoTOTAiN Sokrel. 



Calyx herbaceous, of 4 sepals ; the two outer smaller and spreading, the two 

 inner broader and erect (but unchanged) in fruit. Stamens 6. Stigmas 2, ses- 

 sile, tufted. Achenium lenticular, thin, flat, much larger than the calyx, sur- 

 rounded by a broad and veiny wing. Seed flattened in the opposite direction 

 from the wing. Embryo straight, occupying the centre of the albumen, slender. 

 — Low alpine perennials, with round-kidney-form and long-petioled leaves chief- 

 ly from the root, obliquely trancate sheaths, and small greenish flowers clustered 

 in panicled racemes on a slender scape. (Name from o|vj, sour, in allusion to 

 the acid flavor of the leaves, similar to that of Sorrel.) 



1. O. digyna, Campd. Leaves all round-kidney-form, usually notched 

 at the end ; fruit orbicular. — Alpine region of "White Mountains, New Hamp- 

 shire, Oakes, &c., and high northward. (Eu.) 



4. RtlMEX, L. Dock. Soekel. 



Calyx of 6 sepals ; the 3 outer herbaceous, sometimes united at the base, 

 spreading in frait; the 3 inner (called valves) larger, somewhat colored, increas- 

 ing after flowering and convergent over the 3-angled achenium, veiny, often 

 healing a grain-like tubercle on-the outer surface. Stamens 6. Styles 3 : stig- 

 mas tufted. Embryo slightly curved, lying along one side of the albumen, 

 slender. — Coarse herbs, with small and homely (mostly green) flowers, which 

 are crowded and commonly whorled in panicled racemes ; the petioles some- 

 what sheathing at the base. (The ancient Latin name of these plants; of un- 

 known etymology.) 



§ 1 . LAPATHUM, Tourn. — Flowers perfect, or moncedously polygamous : styles 



free : herbage bitter, 



* Leaves all lanceolate and acute at both ends, flat, smooth: valves of the fruiting 



calyx entire, or nearly so, not aum-bearing : root perennial. 



1. K. verticillatus, L. (Swamp Dock.) Racemes nearly leafless, 

 elongated, the flowers in crowded whorls ; fruit-bearing pedicels slender, club- 

 shaped, abruptly refkxed, 3-4 times longer than the fruiting calyx ; the valves dilated- 

 rhomboid, obtusely somewhat pointed, strongly n{gose-reticulated, each bearing u. very 

 large grain, from J to i the width of the valve. — Wet swamps and ditches ; 

 common. June, July. — Stem 2° -4° high, branched above, with pale green, 

 willow-like, thickish, wholly entire leaves. — E. Britannica, i., I now suspect 

 to be founded upon this same species. 



2. B. altissinins, Wood. (Tall Dock.) Kaccmes spike-like and 

 panicled, nearly leafless (3° -6° high) ; whorls crowded; pedicils nodding, rather 

 shorter than the fruiting calyx ; the valves round-heart-shaped, obtuse, thin, 1 - 3 of 



