Plants and Animals

Lycopus virginicus Virginia water-horehound

species photo
species photo
species photo

Key Characteristics

Medium-sized forb of floodplain forests; stem without a tuberous base as in the similar-looking L. uniflorus; leaves elliptic and coarsely serrate; flowers tiny and white; fruits a set of four tiny nutlets (each 1.5-2 mm long), with tiny (1 mm) triangular calyx lobes not longer than the nutlets.

Status and Rank

US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G5 - Secure
State Rank: S2 - Imperiled

Occurrences

CountyNumber of OccurrencesYear Last Observed
Bay 2 2019
Ingham 4 2014
Kalamazoo 1 2008
Kent 1 2016
Lenawee 4 2008
Midland 1 2014
Muskegon 1 1994
Wayne 1 2003

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

Virginia water-horehound is locally common in first and second bottoms of floodplain forests, particularly along the Red Cedar River in Ingham County and the River Raisin in Lenawee County.

Natural Community Types

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

Trees: Acer saccharinum (silver maple), Celtis occidentalis (hackberry), Fraxinus pennsylvanica (green ash), Populus deltoides (cottonwood), Salix nigra (black willow), Ulmus americana (American elm).

Shrubs and Vines: Cephalanthus occidentalis (buttonbush), Parthenocissus quinquefolia (Virginia creeper), Toxicodendron radicans (poison-ivy), Vitis riparia (riverbank grape).

Herbs: Arisaema dractonium (green dragon), Carex grayi, C. grisea, C. lupulina, C. muskingumensis, C. stipata, Cinna arundinacea (wood reedgrass), Elymus riparius (riverbank wild-rye), E. virginicus (Virginia wild-rye), Iris virginica (southern blue flag), Laportea canadensis (wood nettle), Leersia virginica (white grass), Onoclea sensibilis (sensitive fern), Persicaria virginiana (jumpseed), Pilea pumila (clearweed), Rumex verticillatus (water dock), Saururus cernuus (lizard's-tail), Scutellaria lateriflora (mad-dog skullcap), Symphyotrichum lateriflorum (calico aster), Teucrium canadense (wood sage), Verbena urticifolia (white vervain).

Management Recommendations

Primarily requires protection of habitat and maintenance of riparian hydrological regime. Possibly sensitive to excessive timber harvesting and river pollution.

Survey Methods

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

  • Meander search

    • Survey Period: From third week of August to fourth week of October

References

Survey References

  • Elzinga, C.L., D.W. Salzer, and J.W. Willoughby. 1998. Measuring and Monitoring Plant Populations. The Nature Conservancy and Bureau of Land Management, Denver. BLM Technical Reference 1730-1. 477pp.
  • Goff, G.F., G.A. Dawson, and J.J. Rochow. 1982. Site examination for Threatened and Endangered plant species. Environmental Management 6(4): 307-316
  • Nelson, J.R. 1984. Rare Plant Field Survey Guidelines. In: J.P. Smith and R. York. Inventory of rare and endangered vascular plants of California. 3rd Ed. California Native Plant Society, Berkeley. 174pp.
  • Nelson, J.R. 1986. Rare Plant Surveys: Techniques For Impact Assessment. Natural Areas Journal 5(3):18-30.
  • Nelson, J.R. 1987. Rare Plant Surveys: Techniques for Impact Assessment. In: Conservation and management of rare and endangered plants. Ed. T.S. Elias. California Native Plant Society, Sacramento. 8pp.

Technical References

  • Cooperrider, T.S. 1995. The Dicotyledonae of Ohio Part 2. Linaceae through Campanulaceae. Ohio State University Press, Columbus. 656pp.
  • Crow, G.E. and C.B. Hellquist. 2000. Aquatic and Wetland Plants of Northeastern North America. Volume 1. Pteridophytes, Gymnosperms, and Angiosperms: Dicotyledons. University of Wisconsin Press, Madison. 480pp.
  • Gleason, H. A., and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second edition. The New York Botanical Garden, Bronx. 910pp.
  • Godfrey, R.K. and Wooten. 1981. Aquatic and Wetland Plants of Southeastern United States. Dicotyledons. University of Georgia Press, Athens. 712pp.
  • Gray, A. 1950. Gray's Manual of Botany; eighth ed. Van Nostrand Reinghold, New York. 1632pp.
  • Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the vascular plants of Northeastern United States and adjacent Canada. New York Botanical Garden, Bronx. 937pp.
  • Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region, 4th ed. Indiana Academy of Science, Indianapolis. 921pp.
  • Voss, E.G. 1996. Michigan Flora. Part III. Dicots (Pyrolaceae-Compositae). Bulletin of the Cranbrook Institute of Science and University of Michigan Herbarium. 622pp.
  • Waterman, A.H. 1960. The Mints (Family Labiatae) of Michigan. Michigan State University. Biological series, Vol. 1 No. 8

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