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Spiney Sowthistle Sonchus asper

Phonetic Spelling
SON-chus AS-per
Description

Sonchus asper, or Prickly Sowthistle, is a spring or summer annual herbaceous wildflower, with spiney leaves and yellow flowers and is often considered a weed because of its aggressive spread. Prickly Sowthistle typically grows in full sun, moist to slightly dry conditions, and different kinds of soil, including loam, clay-loam, and shallow gravelly soil. It is often found in lawns, waste places, and roadsides.The size of this plant varies depending on the moisture and fertility of the soil. It can bolt upward and form flowerheads very quickly during the summer. In a garden setting, be careful not to let this plant go to seed. The seeds spread by wind and water and the plant can tend to take over a site. 

The plant is not frost tender and flowers from June to August. The seeds ripen from July to September.

 

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#weeds#aggressive#herbaceous#wildflower garden#annual weed
 
Cultivars / Varieties:
Tags:
#weeds#aggressive#herbaceous#wildflower garden#annual weed
  • Attributes:
    Genus:
    Sonchus
    Species:
    asper
    Family:
    Asteraceae
    Life Cycle:
    Annual
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Eurasia and North Africa
  • Whole Plant Traits:
    Plant Type:
    Weed
    Wildflower
    Habit/Form:
    Erect
    Growth Rate:
    Rapid
    Maintenance:
    Low
    Texture:
    Coarse
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Soil Texture:
    Clay
    Loam (Silt)
    Shallow Rocky
    Soil Drainage:
    Moist
    Occasionally Dry
  • Fruit:
    Fruit Color:
    Black
    Display/Harvest Time:
    Fall
    Fruit Type:
    Achene
    Fruit Description:
    Each floret is replaced by an achene with a tuft of silky white hairs. The achenes are flat, spindle-shaped, hairless, and have several longitudinal ribs. They are distributed by the wind. This plant spreads by reseeding itself.
  • Flowers:
    Flower Color:
    Gold/Yellow
    Flower Bloom Time:
    Spring
    Summer
    Flower Petals:
    more than 20 petals/rays
    Flower Size:
    < 1 inch
    Flower Description:
    The upper stems terminate in clusters of 1 to 5 composite flowers on rather short stalks. Each flower is about 2/3 inch across when fully open, consisting of numerous yellow ray florets. The base of each flower is covered with dull green bracts and is it rather short. The blooming period can occur from late spring to early fall, and usually lasts about a month for a colony of plants.
  • Leaves:
    Leaf Color:
    Green
    Leaf Feel:
    Glossy
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Lanceolate
    Oblanceolate
    Pinnatifid
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    > 6 inches
    Leaf Width:
    3-6 inches
    Leaf Description:
    Large basal leaves and smaller, curved upper leaves have soft, very spiny teeth. Margins are spiny and wavy, white mid-vein, large round basal lobes clasping - curled downward, often dark green and glossy. Leaves are up to 10 inches long and 3½ inches across, but more commonly they are about half this size or less. On shorter plants, they are rather crowded together on the stems, even where the composite flowers occur. Depending on the local form of the plant, these leaves may be pinnatifid, or they may lack significant lobes along the margins, in which case they are broadly lanceolate or oblanceolate.
  • Stem:
    Stem Color:
    Green
    Stem Is Aromatic:
    No
    Stem Cross Section:
    Round
    Stem Form:
    Straight
    Stem Surface:
    Smooth (glabrous)
    Stem Description:
    Upright, smooth, stems branched sparsely above. The stems have rather conspicuous longitudinal veins and are usually hairless, although occasionally the upper stems and flowering stalks have a few hairs.