Polygonum erectum
Encyclopedia
Polygonum erectum is an annual plant species with upright or ascending stems. It is a common weed in disturbed locations with dry soils in the North Eastern USA where it is called Erect knotweed.
s are shorter or equal the length of the calyx and typically longer than the ocreae. The closed flowers have a calyx that is typically 3 mm long, green in color and 5-lobed. Flowers in clusters of 1 to 5 in cymes that are produced in the axils of most leaves. The calyx segments are unequal with the outer lobes longer and not keeled and the inner ones narrowly keeled. The tepal
s are greenish, with yellowish tinting or sometimes with whitish tints. The seeds are produced in fruit
s called achene
s that can be of two different types; one type is dark brown in color with a shiny surface and is broadly ovoid in shape, typically 2.5 mm long. The other achene type is dull brown in color, exsert and ovoid in shape, and 3–3.5 mm long. Late season fruiting is uncommon and if produced the achenes are 4 to 5 mm long.
Polygonum erectum is listed as endangered in New Hampshire
and New York
Description
Plants grow 10 to 50-(75) cm tall with many to few, non wiry branches. The leaves have distinct veins and entire edges or have jagged cut edges. The pedicelPedicel (botany)
A pedicel is a stem that attaches single flowers to the main stem of the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower....
s are shorter or equal the length of the calyx and typically longer than the ocreae. The closed flowers have a calyx that is typically 3 mm long, green in color and 5-lobed. Flowers in clusters of 1 to 5 in cymes that are produced in the axils of most leaves. The calyx segments are unequal with the outer lobes longer and not keeled and the inner ones narrowly keeled. The tepal
Tepal
Tepals are elements of the perianth, or outer part of a flower, which include the petals or sepals. The term tepal is more often applied specifically when all segments of the perianth are of similar shape and color, or undifferentiated, which is called perigone...
s are greenish, with yellowish tinting or sometimes with whitish tints. The seeds are produced in fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
s called achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
s that can be of two different types; one type is dark brown in color with a shiny surface and is broadly ovoid in shape, typically 2.5 mm long. The other achene type is dull brown in color, exsert and ovoid in shape, and 3–3.5 mm long. Late season fruiting is uncommon and if produced the achenes are 4 to 5 mm long.
Polygonum erectum is listed as endangered in New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
and New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...