Bidens beckii (Water-marigold) - photos and description
General: Aquatic plant with roots anchored in soil. Plants glabrous.
Flowers: Flower heads solitary, terminal, the ray florets yellow, flower heads measured to 4 cm diameter, central disk measured at 1 cm diameter (the diameter of the flower head is listed incorrectly at 1 cm in a couple of field guides we use). Involucral bracts lanceolate. Plants begin flowering in mid-August.
Leaves: Usually a single pair of leaves grow above the water, they are opposite, lanceolate, serrate, sessile, measured to 28 mm long by 10 mm wide. Submerged leaves in whorls of six, finely dissected into filiform segments; a submerged leaf measured at 2 cm long.
Height: We measured flowering stems rising to 7 cm above the water.
Habitat: Shallow water in the boreal forest.
Abundance: Very rare, listed as an S2 (as of 2021) by the Saskatchewan Conservation Data Centre.
Origin: Native.
Synonym: Listed in some of the guides we use as Megalodonta beckii.
When and where photographed: The above photos were taken August 21st, 1 to 1.5 metre depth of water, near shoreline in lake, Porcupine Hills, about 400 km north east of our home in Regina, SK.