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Oklahoma State University Stillwater, OK |
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Oklahoma Alfalfa |
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Oklahoma State University Stillwater, OK |
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Oklahoma Alfalfa |
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Spiny Sowthistle |
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COMMON NAME: |
Spiny Sowthistle, Prickly Sowthistle |
| SCIENTIFIC NAME: | Sonchus asper (L.) Hill |
| TYPE: | Annual Cool-season Broadleaf |
| DESCRIPTION | |
| Germination: | September-November. |
| Reproduction: | By seeds, May-August. |
| Stems: | The stems are erect, branching only in the inflorescence to sparsely branching. |
| Leaves: | The leaves of the spiny sowthistle alternate and are simple bladed. The lower blades are ovate to obovate and range from pinnatifid to lobed or they can be subentire, prickly, with clasping bases and rounded auricles. The blades of the middle and upper leaves are reduced in size and are less divided. |
| Flowers: | The flowers of the spiny sowthistle are yellow, fertile, and ligulate, with the ligulate being shorter than the corolla tube. |
| Fruit/ Inflorescence: |
The fruit is a one-seeded flattened achene, that is ribbed with 3-5 ribs on each face. It is without wrinkles, brown in color, and the margins are small with recurved spines. The pappus is of white bristles which soon separate from the achene body. |
FOUND: |
The spiny sowthistle is found primarily in cultivated fields, pastures, disturbed sites, gardens, waste places, roadsides, and only occasionally in alfalfa. |
CONTROL: |
Usually not enough to control. |
| Jim Stritzke Former Alfalfa Weed Control Specialist Department of Plant and Soil Sciences Oklahoma State University |
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