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 Flower head Watson LakeSue Smith |  Leaf Watson LakeSue Smith |  Leaves - underside Watson LakeSue Smith |  Leaf - dense hairs Watson LakeSue Smith |  Plant - summer Watson LakeSue Smith |  Stems - spiny wings Watson LakeSue Smith |
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Origin:
Introduced
Life Cycle:
Biennial or annual Similar Species: Cirsium
General Desc:
Autumn seedlings behave as a biennial, producing a rosette with a taproot that may extend down 1 foot or more. Early in the second year, the plant bolts and flowers. Summer seedlings can behave as annuals. Naturalized.
Identification notes: Taprooted, primarily binennial; branches erect, appressed; leaves spiny hairy, basal; conspicuous spiny-winged stems; purple to reddish flowers of 18 to 50 ray flowers. Similar to Cirsium spp. distinguished by a fleshy and honey-combed receptacle.
Height:
Often 8 feet or more
Habitat Description: Disturbed sites, roadsides, grasslands, woodlands. Grows best in sandy, sandy clay and calcareous soils that are rich in ammonium salts.
Plant Communities:
Interior Chaparral, Semidesert Grasslands, Pinyon Juniper Woodland, Montane Conifer Forest, Disturbed Areas
Elevation: 3000 - 10000 feet
Color:
Purple to reddish
Shape:
Daisy or dandelion-like not in clusters
Tubular:
N
Flowering Period:
Jun - Sep
Description:
Globe-shaped flower heads of disc flowers only, are 1 to 2 inches in diameter, bracts are spine-tipped.
Leaf Color:
Grayish-green
Leaf Type:
Simple
Leaf Shape:
Round or oval
Leaf Margin:
Toothed
Leaf Attachment:
Basal and alternate
Leaves Clasp:
N
Hairs:
Leaves
Spines:
Y
Leaf Description:
Stems have broad spiny wings of ribbon-like leaf material. Leaves are large, densely hairy, spiny and covered with dense hairs. Basal leaves may be up to 2 feet long and 1 foot wide, withering with age.
Fruit Color: Gray-black
Fruit Type: Achene
Seed Notes: Seeds are smooth, slender, and tipped with slender, barbed bristles. A single plant can produce 8,400 to 40,000 seeds. Seeds are sensitive to light and only germinate when close to the surface.
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