Asteraceae : Cirsium drummondii
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Family Name
Asteraceae
Common Name
Drummond's thistle
Description
Cirsium drummondii is a biennial or perennial herb growing to 110 cm tall and blooming only once before dying. The plants are stout-stemmed and unbranched. The alternate leaves are oblanceolate, 8-25 cm long and 1.5-6.5 cm wide., with a spinose margin. The lower leaves are larger and more numerous toward the base, ascending and the upper leaves are deeply divided with the segments triangular in shape. The inflorescence is a terminal head (occasionally 2-3), about 7 cm in diameter with an involucre of 4-7 rows of bracts, 2-3.5 cm long, the outer 2 rows purplish and spine tipped. Ray flowers are lacking, with disk flowers rose purple in color and 38-44 mm long and the style is exerted. The achenes are straw colored with purplish streaks and a yellowish rim 4-5.5 mm long and < 2 mm wide with a bristly pappus 30-40 mm long. Drummond’s thistle blooms from June to early August in moist meadows, pine woodlands and along roadsides only in the Black Hills of Wyoming and South Dakota.
Horticulture Notes
Seed Collection: Collect seed in mid to late summer when achenes are dark yellow and the heads appear fuzzy.
Germination: No pretreatment needed
Soils: Sandy or other well drained soils containing moderate to high amounts of organic matter.
Light: Full sun
Water: Prefers moist conditions
Notes: Thistles are often considered noxious weeds and may attract an unpleasant response by neighbors.
Additional Notes
Drummond’s thistle is an uncommon flower in the United States. The profile is very rugged and it is not commonly cultivated.