Pl.ex.mo7i . 3 5. POLYGONEAS. 33. Bristorta. 267 
cidium) naked, or joined to the perigonium ; perisperm 
farinaceous, rarely nearly wanting; corculum inverse, lateral, 
rarely central ; plumula inconspicuous ; radicle above. — 
Stem herbaceous, rarely shrubby ; leaves alternate, sheath- 
ing at their base, or with an intrafoliaceous adnate sheath ; 
younger leaves revolute beneath ; flowers hermaphrodite, 
rarely unisexual, spiked or racemose. 
Perigonium 4 or 8-parted, not falling off. 
Flowers spiked, terminal Bistorta. 33. 
Flowers spiked or panicled; spikes many Persicaria. 34. 
Flowers axillary Polygonum. 35. 
Flowers corymbose ; thecidium 3-sided Fagopyrum. 36. 
Perigonium 4 or 6-sepaled, inner ones persistent > outer reflexed . 
Stigmata 3 ; corculum lateral ; 
inner sepales tubercular at the base Lapathum. 37. 
Stigmata 3 ; corculum lateral ; 
inner sepales not tubercular at the base .... Acetosa. 38. 
Stigmata 2 ; corculum central ; 
inner sepales not tubercular at the base Oxyria. 39. 
I. 33. BISTORTA. Snakeweed . 
Perigonium 5-parted, persistent; stamens 8; 3 opposite 
and 5 interposed ; styles and stigmata 3 ; thecidium 3-an- 
gular; corculum lateral. — Rhizoma tortuous; stem simple; 
ocreoe 2-valved, 2-flowered ; flowers spiked ; spike solitary, 
terminal. 
1 . Bistorta major . Great snakeweed. 
Leaves ovate, waved ; radical leaves decurrent into a pe- 
tiole ; spike dense, obtuse. 
Bistorta major, Rail Syn. 1 4T, 1 ; Ger. em. 399, 1. 
Bistorta major vulgaris, Park. 391. 
Polygonum Bistorta, Lin. S. P 516. 
Polygonum amoenum, Salisb. Prod. 258. 
Bistort Oyster loit. Passions , Cheshire. Patience dock , Manchester. 
Fields and pastures ; perennial ; May and June. 
Stem 18 in. high; leaves beneath, glaucous, veined; spike 
erect, many-flowered; flowers pedicelled. — Young shoots 
eaten as a potherb ; root strongly astringent, used also in 
tanning leather. 
