78 ENGLISH BOTANY. 
form: nearly smooth when growing in marshes: and quite smooth 
when growing in water, with minute raised dots but no superficial 
glands beneath. ; 
In waste places, cultivated fields, and by roadsides; also in marshes, 
ponds, and ditches. Common, and generally distributed. 
England, Scotland, Ireland. Perennial. Late Summer, Autumn. 
This plant presents two very distinct aspects, according to its place 
of growth. When growing in dry places the stem is 1 to 3 feet high, 
usually simple, or with short branches in the axils of the leaves; the 
leaves have short stalks, } to 1 inch long; and lamin 3 to 18 inches 
long, generally very rough to the touch, though sometimes, when 
growing in marshy places, nearly smooth; the ochre are generally 
clothed with hairs; the spikes are 3 to 24 inches long, and the fruit 
appears very rarely to attain to maturity. In the aquatic form, the 
length of the stem depends on the depth of the water, as the flower 
always rises above the water; the leaves are coriaceous and float 
on the surface; the petioles are 1 to 3 inches long; the lamina some- 
what resembles that of Potamogeton natans, but is narrower and more 
parallel-sided, the length varies from 2 to 5 inches, and the surface 
is destitute of hairs, as are also the ochrew; the spike is not above 1 
to 14 inch long, thicker in proportion, and often perfects its fruit. 
In both forms the bracts are acuminate or cuspidate, scarious 
brown, surrounding the fascicles, but not the rachis. The perianth 
is } inch long, pale bright rose. Stamens exserted. Nut % inch 
long, dark chestnut, with difficulty separated from the perianth. When 
growing in dry places, the plant frequently does not flower. ° 
Amphibious Bistort. 
French, Renouée amphibie. German, Ortwechselnder Knéterich. 
Dr. Withering says, “ Water fowls are said by Curtis to be fond of the seeds. 
Greville designates the plant a mischievous weed.” 
Section V.—BISTORTA. Tournef. (non Meisn.). 
Stems unbranched, erect. Leaves chiefly radical, ovate, oblong or 
lanceolate, often waved at the edges. Flowers in a solitary terminal 
spikelike raceme or spike. Perianth not accrescent. Stamens 8. 
Styles 3, elongate. Embryo lateral; cotyledons narrow, foliaceous, flat. 
SPECIES XUI—POLYGONUM BISTORTA. Linn. 
Prats MCCXLIIL 
Billot, Fl. Gall. et Germ. Exsice. No. 2357. 
Perennial. Rootstock slender, woody, rather extensively creeping, 
much branched; the branches terminating in enlarged tubers, gene- 
