Bidens vulgata (Tall Beggarticks) - photos and description

Flower head on August 29th, bracts of unequal length

Flower head on August 29th

Flower head on September 10th, bracts uniform in size

Flower head on September 10th

Leaves 3 to 5 pinnate.

General: Erect, coarse annual with a branching growth habit. Stems purple-red and rough hairy.

Flowers: Flower heads terminal on long peduncles, discoid, quite variable in size, we measured flower heads from 9 mm to 30 mm in diameter. We counted 10 to 16 outer involucral bracts, outer involucral bracts elliptical to spatulate.

Leaves: Leaves mostly opposite, 3 to 5 pinnate, leaflets are lanceolate, serrate. The leaf highlighted in the photo above was 75 mm long by 80 mm wide, its end leaflet was 50 mm long by 20 mm wide. Leaf bottoms pubescent with long hairs, top of leaves pubescent with short hairs.

Height: Plant not described in Flora of Alberta or Budd's Flora, we measured plants to 111 cm tall.

Habitat: Wet soil, marshes, moist woods.

Abundance: Common, ranked as an S5 by the Saskatchewan Conservation Data Centre. Bidens vulgata has been rare in our experience while the similar species Bidens frondosa, which is ranked as an S3 (rare), we have found to be more common.

Origin: Native.

Similar species: This plant is quite similar to Bidens frondosa, however the flower heads of that plant have 6 to 8 outer involucral bracts, whereas the flower heads of Bidens vulgata have 10 to 16 outer involucral bracts. The flower heads on Bidens frondosa are smaller in diameter, usually 8 mm in diameter, while Bidens vulgata's flower heads can grow to 30 mm in diameter.

When and where photographed: Photos were taken August 29th on the shore of Wascana Lake in Regina, SK, and August 25th and September 10th, prairie wetland about 175 km northwest of our home in Regina, SK.