Prairie
Dock Silphium
terebinthinaceum
Description:
The Prairie Dock is a native, warm-seasons perennial herb belonging to
the Compositae, or aster family. It is one of the four
Leaf: The leaves are a most distinctive part of this
plant in that they are rough like sandpaper and are confined to the base of the
plant. They are spade shaped blades, often more than 40 cm long and up to 30 cm
wide.
Flower: The flower heads are in an open cluster at
the top of the tall stalk. The numerous, yellow heads have both ray and disk
flowers. They range from 3.5 to 8 cm broad. The rays number from 12 to 20’ per
head.
Blooming months: July-September
Stem: A
smooth, shiny, nearly leafless 2- to 10’-tall stalk.
|
|
|
|
|
|
|
|
|
June 6 |
|
|
Discussion:
This species forms a gum or rosin which is used in various ways. It was
chewed by early settlers as a gum. In open prairies, the leaves of Prairie Dock
often orient themselves along a north-south axis, facilitating maximum leaf
exposure to sunlight.
Distribution:
This species is a characteristic plant of prairies. Prairie Dock ranges
throughout most of the
Native
or Introduced to
Location:
N41048.677’ W089040.972’
Copyright:
© 2004 Nancy Trainor,
References:
Keller, Carolyn. Prairie Plants of
Ladd, Doug. Tallgrass Prairie Wildflowers, The Nature Conservancy, 1995.
Peterson, Roger Tory. Wildflowers Northeastern/North Central
Mohlenbroch, Robert H., and John W. Voigt. Prairie
Plants of
Return
to Challand Middle School Prairie Project home page
Return
to Mrs. Trainor’s 7-1 Life Science home page