Rumex pseudonatronatus (Field Dock) - photos and description

 

 

 


Fruit in above photo, valves with entire (not toothed) margins.


Fruit in above photo, valves with entire (not toothed) margins.


Only one weakly developed tubercle per fruit.


Pedicels jointed.


Pedicels jointed

General: Stout, erect, single-stemmed perennial, inflorescence tall and narrow. Plants glabrous.

Flowers: Numerous, small, greenish.

Fruit:  Fruit is a three-sided achene, each side triangular in shape and known as a valve. The valves are entire. We observed one weakly developed tubercle on 1 out of 3 valve surfaces per fruit. Valve measured at 4 mm long by 4 mm wide.

Leaves: Leaves alternate, linear-lanceolate, the margins strongly undulate (wavy), we measured a leaf at 200 mm long by 38 mm wide. Leaves reduced in size upwards.

Height: Height is listed in Flora of Alberta to 150 cm, we measured plants to 136 cm tall.

Habitat: Moist ground.

Abundance: Common.

Origin: Introduced.

How to identify this species of Rumex: Pedicels jointed, 1 weakly developed tubercle per fruit, valves with entire margins, leaves undulate. (Taxonomic Reminder for Recognizing Saskatchewan Plants, and Wetland Plants of the Northern Great Plains).

Similar species: This plant might be confused with Rumex stenophyllus which also has wavy-margined leaves, and jointed pedicels. However, that plant has valves with coarse teeth, and has 3 tubercles per fruit, whereas R. pseudonatronatus has valves with entire margins, and only 1 weakly developed tubercle per fruit.

This plant might be confused with Rumex crispus which also has wavy-margined leaves, and jointed pedicels. However, that plant has 3 tubercles per fruit, whereas R. pseudonatronatus has only 1 weakly developed tubercle per fruit.

When and where photographed: Photos taken July 2nd, wetland on edge of cropped field, about 60 km southeast of our home in Regina, SK.