Potentilla supina ssp. paradoxa (Bushy Cinquefoil) - photos and description

 

 

 


Flower approximately 12 mm in diameter.


Flower approximately 12 mm in diameter.

 

 

 

General: Annual or biennial plants with a low, bushy growth habit. Stems many from the central caudex, plants with stems spreading to ascending. Stems leafy, pubescent, red-coloured at their base.

Flowers: Flowers are many, bright yellow, the sepals as long as or longer than the petals. The petals are heart-shaped, widest at the apex, narrowed at their base. The flower petals begin to fall from the flowers at about 1:30 pm, the plants are best viewed (and photographed) in the morning.

We measured flowers from 12 to 14 mm in diameter, and flower petals to 5 mm long. The Flora of North America lists this plant's petal length at 2.5 to 5 mm (it doesn't list a flower diameter).

Our measured flower diameter of 12-14 mm is at odds with some field guides we use which list the flower diameter from only 5-7 (9) mm.

I'm doubtful this plant's flower could only be 5-6 mm in diameter if a single petal is 2.5 to 5 mm long (as described in Flora of North America); furthermore a flower diameter of only 5-6 mm would be extraordinarily small for a species of Potentilla. I think the field guides may have it wrong listing such a small flower diameter for this species, the field guides are wrong at least for the plants I've found in Saskatchewan.

I checked specimens of this plant at the U of Regina Ledingham herbarium in an attempt to measure their flower diameter. None of the ten or so specimens had flowers, all their flower petals had been shed when or after the plants were collected.

Leaves: The leaves are alternate, lower leaves are 5-11 pinnate, the topmost leaves with only 3 leaflets. The leaves are elliptical, we measured a leaf at 70 mm long by 34 mm wide. Leaflets are elliptical to ovate, cuneate (wedge-shaped) at their base, and having very short hairs on leaf bottoms, ciliate, and glabrous on leaf tops. We measured a large leaflet at 22 mm long by 11 mm wide.

Height: Height listed in Budd's Flora to 50 cm, we've measured plants to 22 cm tall, and with a spread to 105 cm.

Habitat: Sandy lakeshores, riverbanks, low moist places.

Abundance: Very rare, this plant is ranked as an S2 by the Saskatchewan Conservation Data Centre.

Origin: Native.

How to identify this species of Potentilla: More or less biennial, stems leafy, leaves pinnate with 5-11 leaflets, flowers many, petal length is less than or equal to sepals.

Synonym: Listed in many of reference books we use as Potentilla paradoxa.

When and where photographed: The above photos where taken August 16th, sandy, weedy shoreline of Last Mountain Lake, about 40 km northwest of our home in Regina, SK.