Dyssodia papposa (Fetid-Marigold) - photos and description


Clump of several plants





General: Much-branched, erect annual plant. Stems sparsely hairy.

When I first encountered this plant, I could smell it before seeing it. The plant has a very strong, unpleasant smell of Marigolds. One of its older synonyms is in fact Tagetes papposa and Tagetes is one of the genera for ornamental Marigolds.

Flowers: Flowers are orange-yellow, flower heads were measured at 7 mm long and 5 mm wide. We counted 4 to 8 ray florets, a ray floret was measured at 1 mm long. The involucre bracts are linear, involucre measured from 5 to 7 mm long.

Leaves: Leaves mostly opposite, although top most leaves may be alternate or opposite. Leaves are pinnately dissected into linear lobes. Leaf highlighted in photo above was 25 mm long and 14 mm wide. Lobes were 1 mm wide. Leaves glabrous or with a few hairs.

Height: Plant not described in Budd's Flora, we measured plants to 27 cm tall, although most plants were 15 cm tall or less.

Habitat: Habitat is roadsides on the prairies. I see this plant often on the shoulders of paved highways, but have observed it will not be found on the shoulders of that highway's nearby grid roads. It seems other species out-compete it along Saskatchewan grid roads.

Abundance: Listed as uncommon in Checklist of the Vascular Plants of Saskatchewan, however I think it's now common in the province.

Origin: Introduced. Native to Montana and North Dakota according to the USDA, but is considered introduced into Saskatchewan.

When and where photographed: These photos were taken August 28th, paved roadside, parklands, about 40 km east of our home in Regina, SK.