Rumex verticillatus
Rumex crispus
Rumex altissimus
Rumex crispus
Rumex obtusifolius
Rumex acetosella
Tovara virginiana
Polygonum ramosissimum
Erect
Knotweed (Polygonum erectum). A tiny
weed found in lawns and sidewalk cracks and other
places where weeds must be short to survive. The
little white flowers sit in the leaf axils; if you
look very closely, you will see the attractive green
stripes on their petal-like sepals. In fact this is a
plant worth a close look.
Polygonum aviculare
Polygonum coccineum
Polygonum pensylvanicum
Polygonum orientale
Polygonum hydropiper
Oriental Lady’s Thumb (Polygonum
caespitosum). It is not easy to sort out
the taxonomy of this humble weed; we are going by the
listing in the USDA
PLANTS database. It is one of several
similar smartweeds that frequently pop up in urban
areas. This one is distinguished by its dense spike of
tiny pink flowers and pointed leaves without
markings; the similar Lady’s Thumb (Polygonum
persicaria or Persicaria maculosa)
has a dark thumbprint mark on each leaf. Look also for
tufts of hairs at the stem joints.
Polygonum persicaria
Polygonum punctatum
Polygonum hydropiperoides
Polygonum sagittatum
Polygonum arifolium
Polygonum convolvulus
Polygonum cuspidatum
Pale Smartweed (Persicaria lapathifolia).
An elegant and beautiful smartweed. Its resemblance to
its poor relations is obvious, but instead of a
prostrate and insignificant dooryard weed, this one
grows into a tall and beautiful fashion-model
wildflower.
Climbing False Buckwheat (Fallopia
scandens). This ubiquitous vine looks a
bit like a bindweed until it starts to bloom; then the
characteristic clusters of tiny flowers of the
knotweed clan reveal themselves. Like bindweeds, it
likes to clamber over a fence or an arbor, or—as it
did here—over the weeds and shrubbery at the edge of
the woods.
Giant Knotweed (Fallopia sachalinensis).
Also known as Sachalin. The lesser-known of two
beautiful but pernicious Japanese invaders, Giant
Knotweed closely resembles its cousin the Japanese
Knotweed (F. japonica), but can be
distinguished by the leaves, which are longer and
pointier and have a heart-shaped base rather than the
rounded base of F. japonica. Like the
Japanese Knotweed, Giant Knotweed can form large
colonies that completely exclude other species of
vegetation.