Prenanthes alba (White Lettuce) - photos and description



Flower heads in bud on July 26th in above photo




General: A forest species with an upright growth habit, and with panicles of drooping, purplish-white flowers. Stems reddish.

Budd's Flora
describes this as a smooth, hairless plant. However, I observed the bottom of the stems were pubescent with coarse, stiff hairs, and the top of the stems were sparsely hairy.

Flowers: Flowers in panicles from upper stems, we measured flowers at 2 cm long.

Leaves: Leaves alternate, reduced in size upwards. Leaves are lobed, the lower leaves have the shape of an arrowhead. Leaf highlighted in above photo was 8.5 cm long and 9.5 cm wide.

Height: Height listed in Budd's Flora to 150 cm. I measured plants to 90 cm tall.

Habitat: Rich woodlands in eastern Saskatchewan.

Abundance: Rare, ranked as an S3 (as of 2021) by the Saskatchewan Conservation Data Centre.

Origin: Native.

How to identify this species of Prenanthes: The arrowhead shape and lobed margins of the leaves distinguishes this plant from the other Prenanthes species growing in Saskatchewan, Prenanthes racemosa, whose leaves are oblanceolate to spatulate.

When and where photographed: Above photos taken August 10th, in moist mixed woods, boreal forest in Duck Mountain Provincial Park, 300 km north east of our home in Regina, SK.