Polygonum persicaria L.
Family - Polygonaceae
Stems - To -1m tall, glabrous, branching at base, erect, herbaceous, from taproot, typically reddish at nodes.
Leaves - Alternate, lanceolate to linear lanceolate, short-petiolate to sessile above, to +11cm long, +/-2cm broad, glabrous to sparse appressed pubescent, typically with purple splotch near middle of blade, entire. Ocrea appressed pubescent friged with cilia. Petioles to 6mm long, red, sparse appressed antrorse pubescent.
Inflorescence - Terminal and axillary racemes +3cm long, +/-1cm in diameter, dense. Bracts subtending flowers (ocreolae) with or without short cilia (-1mm) at summit.
Flowers - Perianth pink to rose or typically whitish at anthesis, to 3.5mm long. Perianth parts glabrous, ovate to orbicular. Stamens 5, 1.7mm long, white, glabrous, adnate to base of perianth parts. Anthers pale yellow to white, .1mm broad. Styles typically 2, .8mm long, white, glabrous. Achenes typically 2-sided, black, shiny, to +/-2mm long.
Flowering - May - October.
Habitat - Moist to wet waste ground, disturbed sites, meadows, streambanks, roadsides, railroads.
Origin - Native to Europe.
Other info. - This species
is recognized by the characteristic purple splotch in the center of the
leaf. The spot is not always present but typically is. The perianth is
somewhat variable in color.
Photographs taken at the Kansas City Zoo, 5-30-99 and 5-11-00.