Ontario Wildflowers website

Prairie Dock
Silphium terebinthinaceum

Other common names: Prairie Rosinweed

Other scientific names: Silphium pinnatifidum

Family: Composite Family (Asteraceae)

Group: Docks

Distinctive features: Large rough leaves, tall flower stems, yellow flowers.

Similar species:
  •   Elecampane (Inula helenium)


Flowers: Summer;  Yellow;  7 or more parts (petals)

Leaves: Simple, Toothed

Height: 100-200 cm (39-78 in)

Habitat: Fields and Open Areas

Grows in Sun/Shade: Sun

Lifespan: Perennial.  

Books: Newcomb's Wildflower Guide: 362    Peterson's Field Guide to Wildflowers: 184   

Native/Non-native: Native

Status:   S-Rank: S1


Photographs: 139 photographs available, of which 11 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Prairie Dock (Silphium terebinthinaceum)

Flowers.

Prairie Dock (Silphium terebinthinaceum)

The whole plant. This one is almost 7 feet tall!

Prairie Dock (Silphium terebinthinaceum)

Closer view of an individual flower.

Prairie Dock (Silphium terebinthinaceum)

Prairie Dock (Silphium terebinthinaceum)

Flowers just opening. Note the three ray flowers on the right flower head have just opened. Like all plants in the Composite Family, the flower head is composed of multiple tiny individual disc and ray flowers.

Prairie Dock (Silphium terebinthinaceum)

Side view of flower.

Prairie Dock (Silphium terebinthinaceum)

Flower buds of Prairie Dock.

Prairie Dock (Silphium terebinthinaceum)

This shows the joint of a flower stem where it branches off from the main upright stem.

Prairie Dock (Silphium terebinthinaceum)

Leaves.

Prairie Dock (Silphium terebinthinaceum)

The leaves are large and rough. They occur only at the base of the plant (basal leaves).

Prairie Dock (Silphium terebinthinaceum)

This photo shows a field of Prairie Dock with a person for comparison.


Range map for Prairie Dock (Silphium terebinthinaceum)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)