Sagina nodosa
Pearlwort
Image of Sagina nodosa

Photo by Susan R. Crispin 

Key Characteristics

Small forb of moist rocky crevices on western Lake Superior shores; stems upright to reclining with short, linear leaves on the lower stem and triangular clustered leaves on the upper stem; flowers small and white, with the petals much longer than the sepals.

Status and Rank

  • State Status: T
  • State Rank: S2
  • Global Rank: G5

Occurrences

County NameNumber of OccurrencesYear Last Observed
Keweenaw181994
Marquette11984
Distribution map for Sagina nodosa

Updated 1/31/2017. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.

Habitat

Pearlwort is found in moist rock crevices along Lake Superior splashed by waves, and less commonly on sandy beaches in full sun.

Natural Community Types

Methodology

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Associated Plants

Serviceberry, dark scaled sedge, flat topped goldenrod, common yarrow, alpine bistort, ticklegrass, bearberry, marsh bellflower, pale Indian paintbrush, hair grass, spike-rush, butterwort, ninebark, silverweed, dwarf Canadian primrose, and wild rose.

Management

This species primarily requires protection of the shoreline habitat and perpetuation of natural disturbance (winter ice, storms, wind) and hydrological regimes. This community occupies a stressed, potentially unstable environment; many of the species found in this community do not tolerate later stages of succession and require management that prevents woody plant encroachment. Protect from development.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgment of the investigator.

Survey Methods

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed Jun 27, 2017]

More Information

See MNFI Species Abstract

References

Survey References

Technical References

Facebook link