444 POLYGONACEAE 
Famity d. POLYGONACEAE — BUCKWHEAT FAMILY 
Plants various in habit. Leaves with manifest, Pieri oe 
stipules (ocreae) and inflorescence not olde: ate, or b ules som 
times obsolete and the inflorescence involuer ate.—Abo piece a id 
800 species, widely distributed.—Some plants iiri da food, others are 
used in ornamental gardening. Many ae are weeds. 
Flowers, or flower-clusters subtended y EIOS BRE 9: no sheaths (ocreae) 
at the nodes of the stem and the bra ribe I. ERIOGONEAE. 
Flowers, or flower-clusters, not involucrat, ‘put subtended 
by sheathing po Pru uh at the nodes of the 
inflorescence: stam 4-8: sheaths (ocreae) sur- 
ECOL, ‘and the branches above each 
ounding 
e į 
Hypanthium ea, developed, d often as a 
Stigmas tufted or fimbriate-pinnatifid. Tribe II. RUMICEAE. 
d not tufted. 
Stamens distinct: herbs or vines without ten- 
rils. Tribe III. POLYGONEAE. 
Stamens with the filaments united into a tube 
e base: vines with tendrils. Tribe IV. ANTIGONONES. 
Tribe V. COCCOLOBEAE. 
Hypanthian well. developed, enclosing the achene. 
I. EnIOGO 
Annual or perennial plants with alternate or whorled leaves and 
bracts: involucres lobed, sessile D. peduncleu, each with few 
or many exserted flowers : achene often swollen at the base. 1. ERIOGONUM. 
II. Rv 
Sepals of pistillate flower distinct, Mod mcm nor with 
spreading horn-like spines 
"nel Eg not developing wings: achene partly exposed, 
2. ACETOSELLA. 
inner s Spalt developing wings: achene included, smooth. 3. RUMEX. 
Sepals of gU pistillate flower partly united into an indurated 
Brccolaie perianth, tne 7 s of the three outer developing into 
spreading horn-like spine 4. EMEX. 
III. POLYGONEAE 
Internodes of the stem and the branches partly adnate. 
Inner sepals not fimbriate, often conspicuously &ccrescent. 
Inner sepals accrescent, wing-like: achene include 
Anthers alike or nearly so: outer sepals reflexed. 5. POLYGONELLA. 
nthers various, those of the filaments with dilated . 
bases very small and imperfect: outer sepals ap- 
ressed. 6. DENTOCERAS. 
Qin er sepals not accrescent: achene partly exposed. T. DELOPYRUM. 
er Po fimbriate, somewhat accrescent. 8.. THYSANELLA. 
iatemiodes of the stem and the branches not adnate. : 
Leaf- RFT aoe E the base: ocreae 2-lobed, becoming 
lac : filaments, at least As inner, dilated. 9. POLYGONUM. 
Lest blades not jointed. at th ase: ocreae [o not 2- 
lobed: filaments slender 
Ocreae cylindric, truncate: ' sometimes fringed. 
Sepals 4: calyx curved : stamens 4 or 5. 10. Tovana. 
Sepals 5. or if fewer, the stamens more than 5: calyx 
not curved. 11. PERSICARIA. 
Vanes oblique, more or less open on the side facing the | 
Sepals neither keeled on the back nor winged: erect 
or reclining herbs 
Racemes collected int terminal corymbs: embryo 
dividing the endosperm by an S-shaped curve: 
Plants smooth. 
Racemes not in terminal corymbs: embryo slender, 
2: one side of the endosperm: plants prickle- 
d. 13. TRACAULON. 
Sepals, a least the outer ones, keeled or winged: 
S with twining stems and branches or large 
nens with numerous hollow stems arising from 
extensively branching rootstocks. 
12. FAGOPYRUM. 
