Polanisia dodecandra (Clammyweed) - photos and description







Looking straight down on a flower

Pods do not have a stipe

Stems are glandular hairy

General: Annual plants that are sticky-hairy and whose foliage is foul-smelling when touched. Larger plants have a branching growth habit. Stems and pods are glandular hairy.

Flowers: Flowers grow in crowded racemes, are creamy-white with 4 petals and 4 sepals. We measured petals at 1 cm long and sepals at 4 mm long. Petals have two lobes and narrow to a stalk-like base. Stamens are reddish in colour, uneven in length and are arranged beneath the petals. We counted up to 17 stamens.

Fruit: Pods are ascending, have little or no stipe, and we measured a pod to 4 cm long.

Leaves: Leaves are opposite and alternate, trifoliate with leaflets oblanceolate in shape. We measured a leaflet to 35 mm long and 11 mm wide. Leaves are ciliate, bottom of leaves are glandular hairy, top of leaves are glabrous.

Height: Height listed in Budd's Flora to 50 cm tall, we measured plants from 6 to 25 cm tall.

Habitat: Disturbed sandy and gravelly soils, stream banks, gravel pits.

Abundance: Very rare, ranked as an S2 (as of 2021) by the Saskatchewan Conservation Data Centre.

Origin: Native.

Similar species: This plant might be mistaken for Peritoma serrulata (Pink Cleome). However, that plant has pods that are pendant, is not glandular hairy, its flowers have 6 or fewer stamens, its stamens are not arranged underneath the petals, and its pods have an elongated stipe.

When and where photographed: The above photos were taken July 14th and July 27th, slopes of gravel pit, Qu'Appelle Valley about 125 km east of our home in Regina, SK.