78 ENGLISH BOTANY. 



form: nearly smooth when growing in marshes: and quite smooth 

 when growing in water, with minute raised dots but no superticial 

 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 ])resents 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 mch long; and laminae 3 to 18 inches 

 long, generally very rough to the touch, tliough sometimes, when 

 grooving in marshy places, nearly smooth ; the ochrea3 are generally 

 clothed with hairs ; the spikes are f to 2 1 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 ochrea3 ; the spike is not above 1 

 to Ih 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 i inch long, pale bright rose. Stamens exserted. Nut ^ inch 

 long, dark chestnut, with difl&culty separated from the perianth. When 

 growing in dry places, the plant frequently does not flower. 



Amphibious Bistort. 



French, Itcnouee amphibie. German, Ortwecliselnder Knuterich. 



Dr. Withering says, " Water fowls are said by Curtis to be fond of the seeds. 

 Grevillc designates the plant a mischievous weed." 



Section V.— BISTORTA. Towmef. (non 3feisji.). 



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 XIII.— POLYGONUM BISTORTA. Linn. 

 Plate MCCXLIII. 

 Billot, Fl. Gall, et Germ. Exsicc. No. 2357. 



Percjmial. Rootstock slender, woody, rather extensively creeping, 

 much branched ; the branches terminating in enlarged tubers, gene- 



