Erigeron strigosus (Whitetop / Daisy Fleabane) - photos and description

Erigeron strigosus

Erigeron strigosus

Erigeron strigosus

Erigeron strigosus

Erigeron strigosus

Erigeron strigosus

Erigeron strigosus
Basal leaf at 9 o'clock in above photo

Erigeron strigosus
Stem leaf in above photo

Erigeron strigosus

General: Annuals with a branching growth habit and a flat-topped inflorescence. Stems stiff and have hairs growing in vertical striations, stems often reddish in colour at the bottom. Mid and lower stem with short hairs and rough to touch.

Flowers:  Flower heads white with yellow disks, grow in compound corymbs, flower heads measured from 12 mm to 15 mm diameter. Involucral bracts imbricate in two series, the bract margins are hyaline. Involucre pubescent, not glandular, involucre measured at 3 mm long. About 60 ray florets, ray florets measured at 3 mm long.

Leaves: Stem leaves alternate, sessile, linear, reduced upwards. Stem leaf (mid-stem) highlighted in photo above was 4.5 cm long by 5 mm wide. Basal leaves are long-petioled, linear, basal leaf highlighted in photo above was 9 cm long (including petiole) and 9 mm wide. Leaves covered with short hairs.

Height: Height listed in Budd's Flora to 80 cm, we measured plants to 61 cm tall.

Habitat: Moist prairie.

Abundance: Rare, ranked as an S3 (as of 2019) by the Saskatchewan Conservation Data Centre.

Origin: Native.

Synonym: Listed in some of the field guides we use as Erigeron annuus.

When and where photographed: These photos were July 14th, Souris River valley about 200 km south east of our home in Regina, SK.