554 POLYGONACEAE. 
Fagopyrum Tataricum (L.) Gaertn. 
Tartary Buckwheat. (Fig. 1317.) 
Polygonum Tataricum J, Sp. Pl. 364. 1753. 
ie eA um Tataricum Gaertn. Fr. & Sem. 2: 182. 
l. 189. f. 6. 1791. 
ee similar to the preceding species, but 
the leaves deltoid-hastate or oblong-hastate, 
often broader than long, 1/-4’ wide, acute or 
short-acuminate at the apex; racemes terminal 
and axillary, mostly solitary, simple and few- 
flowered, long-peduncled; flowers whitish, short- 
pedicelled; achene subacute, 2%’ long, its 
angles crested with 3 prominent lobes above 
the middle, its faces pinnately sulcate from a 
conspicuous groove. 
In waste places, eastern Canada and New Eng- 
land. Adventive from Asia, Summer. 
6. POLYGONUM L. Sp. Pl. 359.1753. 
Annual or perennial, terrestrial or aquatic herbs, some species woody, with erect, pros- 
trate, climbing or floating stems, alternate sessile or petioled entire leaves, continuous with, 
or jointed, to the cylindric funnelform or two-lobed, often lacerate or fringed ocreae. Flowers 
small, normally perfect, green, white, pink or purple, variously clustered, the clusters termi- 
nal or axillary. Pedicels jointed, subtended by ocreae or ocreolae; calyx 4-5-parted or 4-5- 
cleft, the outer sepals or segments somewhat larger than the inner; stamens 5-9, included or 
exserted; filaments filiform, or dilated at the base, glabrous; anthers oblong; style 2-3-parted 
or 2-3-cleft, its branches included or exserted; stigmas capitate; achene lenticular or 3-angled 
(rarely 4-angled ), invested by or exceeding the calyx. Embryo near the end of the seed, in 
one of its angles. [Greek, many-knees, from the swollen joints of some species. ] 
About 200 species, of wide geographic distribution. Besides the following, some 33 others 
occur in the western and southern parts of North America. 
1, Flowers in terminal spicate racemes; calyx 5-cleft or 5-parted; stem not twining. 
Raceme solitary; alpine species; perennial, not aquatic. 1. PF. viviparum., 
Racemes solitary or 2; aquatic or swamp species; perennials. 
Leaves oblong, elliptic, or elliptic-lanceolate, not acuminate. 
Leaves narrowly lanceolate, or oblong- lanceolate, not acuminate. 
Leaves ovate-lanceolate, or oblong-lanceolate, usually acuminate. 
Racemes several or numerous; annuals or perennials, mostly terrestrial. 
Ocreae naked or ciliolate, ‘their limbs not spreading. 
Racemes drooping. 
Achene ovoid; style 2-parted to near the base. 6. P. incarnatum, 
Achene broadly oblong-ovoid; style 2-cleft to below the middle. 7. P. lapathifolium. 
Racemes erect. 
Style-branches scarcely or slightly exserted. 
Achene broadly oblong, biconvex. 
Achene orbicular, flat. 8. 
Style branches long-exserted; achene ovoid, somewhat gibbous. 
Ocreae fringed with bristles, their limbs not spreading. 
Racemes not interrupted, erect; achene lenticular or 3-angled. 
P. amphibium., 
P. Hartwrightii. 
P. emersum, 
Hyp 
. Portoricense. 
. Pennsylvanicum. 
. longistylum. 
0 rH 
bytes 
Ocreae conspicuously fringed; achene broadly ovoid. 10. P. Persicaria, 
Ocreae inconspicuously fringed; achene narrowly ovoid. u1. P. persicarioides. 
Racemes not interrupted, erect; achene always 3-angled. 
Ocreolae conspicuously fringed, 14. P. Opelousanum. 
Ocreolae inconspicuously fringed. 
Leaves mostly glabrous above; achene pointed at the top. 15. P. hvdropiperoides. 
Leaves strigose above; achene pointed at both ends. 13. P. selaceum. 
Racemes not interrupted, drooping. 12. P. Careyi. 
Racemes interrupted, erect or drooping. 
Achene granular and dull; racemes drooping. 16. P. Hydropiper. 
Achene smooth, shining; racemes erect. 17. P. punctatum. 
Ocreae fringed with bristles, their limbs normally spreading. 18. P. orientale. 
2. Flowers in long naked much interrupted spicate racemes; calyx 4-parted. 19. P. irginianum. 
8. Flowers in axillary clusters; stems more or less wiry, not twining. 
Plants prostrate; achene invested by the calyx. 
Achene pointed at the apex, rounded at the base. 
Leaves mostly acute; style 3-parted to below the middle. 20. P. aviculare. 
Leaves mostly obtuse; style 3-parted to the base. 21. P. littorale. 
Achene pointed at both ends, 22. P. Bellardi. 
Plants prostrate; achene protruding beyond the calyx. 
Leaves mostly longer than the internodes; sea beach species. 23. P. maritimum. 
Leaves shorter than the internodes; plant of waste places. 24. P. Rayt. 
