PROTECTING WISCONSIN'S BIODIVERSITY

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Scientific Name	Common Name	Global Rank	State Rank	Federal Status	WI Status

Longstem Water-wort (Elatine triandra)

State Status: SC

Federal Status: none

State Rank: S2

Global Rank: G5

Photo by Janeen Ruby

Counties with Mapped NHI Occurrences

Longstem Water-wort (Elatine triandra), a Wisconsin Special Concern plant, is found in muddy pond and flowage shores. Blooming occurs throughout August, fruiting throughout September. The optimal identification period for this species is early-August through September.

Synonyms:

Elatine triandra var. triandra

Identification

Longstem water-wort is an emergent/floating aquatic forb with 3 petals and 3 sepals. Its seeds are axile, set at different levels in the fruit, marked with transversely elongate, 6-sided areoles, the angular ends of the areoles dovetailed with those of adjacent rows, the longitudinal ridges appearing narrow or broken. Its leaves are linear to obovate, 3-8mm long.

Distinguishing Characteristics and Similar Species

It can be distinguished from Elatine minima, which is the only other species of this genera in Wisconsin, by its fruits, which are three-lobed. (A microscope will likely be necessary to examine these traits.)

Phenology and Reproduction

Phenology

Blooming occurs throughout August, fruiting throughout September.

Life Cycle, Optimum Time to Identify

Annual. The optimal identification period for this species is early-August through late-September.

Habitat

Longstem water-wort is found in muddy ponds and the shores of flowages.

Avoidance Measures and Management Guidance

Avoidance Measures

Avoid broadcast spraying of herbicides and use care with spot spraying.

Because this plant is an annual, work may safely be conducted before the plants emerge or after they have developed mature seeds.

Management Guidance

Minimize disturbance to hydrology, including soil disturbance from rutting.

This species is likely sensitive to water quality. Following BMPs around streams and buffering associated drainages will reduce eutrophication and prevent water quality degradation.

Wildlife Action Plan

Associated Natural Communities and Ecological Landscapes

Species of Greatest Conservation Need (SGCN) are associated with habitats (or natural communities) and places on the landscape. Understanding relationships among SGCN, natural communities and ecological landscapes help us make decisions about issues affecting SGCN and their habitat and how to respond. Download the Wildlife Action Plan association score spreadsheet to explore rare species, natural communities and ecological landscape associations

Issues/Threats and Conservation Actions

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the Wisconsin Wildlife Action Plan because lack of information can threaten our ability to successfully preserve and care for natural resources.

PROTECTING WISCONSIN'S BIODIVERSITY

Longstem Water-wort (Elatine triandra)

Rare Species & Natural Communities

Additional Resources

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