knawel
Family
CaryophyllaceaeScientific Name
Scleranthus annuus
Other Common Names:
German knotgrass
German moss
Habit
Usually a winter annual but occasionally a summer annual that forms dense, prostrate mats. Knawel is commonly mistaken as a grass and is primarily a weed of lawns, turfgrass, and small grains.
Leaves
Cotyledons are linear in outline and less than 1 mm wide with a sharp tip. This leads to their confusion with grasses. Leaves are linear in outline, less than 1 mm wide, also with a sharp tip. Leaves are arranged oppositely along the stem and joined by a thin, clear membrane. Stems grow prostrate along the ground, branched, forming dense mats outward from a central plant.
Identifying Characteristics
Plants with small, linear leaves that initially resemble a grass and inconspicuous green flowers. Due to the overall growth habit and leaf shape, this weed might be confused with Creeping Phlox (Phlox subulata), but the leaves and stems of German moss are not covered in hairs like those of creeping phlox. German moss might also be confused with some of the spurries (Spergula spp.) but lacks the distinctive white or red flowers of these species.
Flower Seed Head
Flowers are inconspicuous, green in color, and somewhat spiny. Flowers occur in clusters that arise from the position between the leaf bases and the stem.
Seed Fruit
A very small (3-4 mm) utricle.
Where Found
Knawel is distributed throughout the eastern United States.
Growth Habit
prostrate and nonwoody
Thorns or Spines
not present
Approximate Flower Diameter
pencil
Dominant Flower Color
green
Flower Symmetry
radial symmetery
Leaf Hairs
has hairs
Leaf Shape
Varies:
needle,
lance
Leaf Arrangement
opposite
Leaf Margin
entire
Leaf Structure
simple
Leaf Stalk
none
Stem Hairs
Varies:
has hairs,
no hairs
Stem Cross Section
round or oval
Milky Sap
not present
Root Structure
fibrous
Life Cycle
winter annual
Ochrea
present
Plant Type
Herb