Murdannia keisak (Hassk.) Hand.-Maz.

Murdannia keisak (Hassk.) Hand.-Maz.
Asian spiderwort, Marsh Dayflower

Threat Level	Category
Established	Forb/Herb

Similar Species May be confused with the following native and/or non-native species. Landscape Alternatives lists native horticultural substitutes	Commelina erecta, C. virginica, Tradescantia virginica

Description

Stems

Stems are 12 to 30 inches long and create dense mats along the ground.

Leaves

Leaves are alternate, lance-shaped and up to 3 inches long with bases that wrap around the stem.

Flowers

Blooming in September through November, the flowers are small and pink-violet with three petals occurring singly or in small clusters at the apex of the stems and in the leaf axils.

Seeds

The fruit is a capsule which contains several very small seeds dispersed by wildlife and water.

Roots

Roots are formed at the nodes of the stems and can have fragments break off to grow a new plant.

Images

Photo: Linda Lee, University of South Carolina, Bugwood.org
More images of Murdannia keisak

Life History

Murdannia keisak is an annual, emergent plant found in wetlands throughout the Southeastern region of the United States. It is native to eastern Asia and was accidently introduced to South Carolina in 1935. The stems are succulent, form roots at the nodes and grow prostrate along the ground, flowering from September to November with small, pink flowers.

M. keisak overruns water edges and marshes and often grows immersed. It frequently forms dense mats that out-compete native vegetation.
The flowers are only open for only a single day and are pollinated by insects. The flowers produce thousands of very small seeds that are dispersed by wildlife and water. It can also reproduce vegetatively when pieces of roots break off and re-root themselves.

Origin and Distribution

Marsh Dayflower is found throughout Asia but is considered to be native to China, Japan, Korea and Tibet. It was thought to be accidently brought to South Carolina in cultivated rice paddies in 1935 where it has escaped and established itself in the southeastern and 2 states in the northwestern United States.

Habitat

Marsh Dayflower is found in freshwater marshes, edges of ponds and streams. It requires full sun to part shade. At times the plant can be submerged.

Management Recommendations

Mechanical Control

Hand Pulling: Not recommended because maintaining all of the root fragments is critical. If broken it can float to a new site, root itself and grow.

Biological Controls

There are no known Biological controls at this time.

Herbicidal Controls

Foliar Spray Method: This method should be considered for large patches of Marsh Dayflower where risk to non-target species is minimal. Air temperature should be above 65 ºF to ensure absorption of herbicides. The ideal time to treat is in late fall or early spring when many native species are dormant.

Glyphosate: Apply a 2% solution of glyphosate plus a 0.5% non-ionic surfactant to thoroughly wet all leaves. Use a low pressure and coarse spray pattern to reduce spray-drift damage to non-target species. Glyphosate is a non-selective systemic herbicide that may kill non-target
partially sprayed plants.

Triclopyr: Apply a 2% solution of triclopyr plus a 0.5% non-ionic surfactant, to thoroughly wet all leaves. Use a low pressure and coarse spray pattern to reduce spray-drift damage to non-target
species. Triclopyr is a selective herbicide for broadleaf species.

Cut Stump Treatment Method: This control method should be considered when treating individual stems or where the presence of desirable species preclude foliar application. This treatment is effective as long as the ground is not frozen.

Glyphosate: Horizontally cut stems at or near ground level. Immediately apply a 25% solution of glyphosate to the cut stump making sure to cover the entire surface.

Triclopyr: Horizontally cut stems at or near ground level. Immediately apply a 25% solution of triclopyr to the cut stump making sure the entire surface is covered.