Oriental lady's thumb
Family
PolygonaceaeScientific Name
Polygonum caespitosum
Other Common Names:
bristled knotweed
bunchy knotweed
Synonyms (former Scientific Names):
Polygonum caespitosum
Persicaria posumbu
Habit
This erect, sprawling summer annual grows up to 3 1/2 feet in height. It flowers from mid summer till the first frost in the fall.
Leaves
The alternately arranged leaves are elliptical in shape, although they can be lance-shaped. They are usually 1 to 3 inches in length, and 1/2 to 1 1/4 inches wide. The leaves are occasionally hairy.
Identifying Characteristics
The first true leaves are hairy
Flower Seed Head
The small, dark pink or red flowers occur in spikes at the tips of stems.
Seed Fruit
The seeds develop in a black achene.
Where Found
This plant can be found in moist, disturbed areas
Growth Habit
prostrate and nonwoody
Thorns or Spines
not present
Approximate Flower Diameter
pencil
Dominant Flower Color
Varies:
red,
pink
Flower Symmetry
radial symmetery
Leaf Hairs
has hairs
Leaf Shape
lance
Leaf Arrangement
alternate
Leaf Margin
entire
Leaf Structure
simple
Leaf Stalk
Varies:
none,
shorter than leaf
Stem Hairs
no hairs
Stem Cross Section
round or oval
Milky Sap
not present
Root Structure
Varies:
fibrous,
taproot
Life Cycle
summer annual
Ochrea
present
Plant Type
Herb