| Justicia americana |
| Water-willow |
Key Characteristics
Mat-forming perennial of river slackwater areas; leaves opposite, narrowly elliptical; flowers pale violet marked with dark purple, borne in axillary clusters near top of plant.
Status and Rank
- State Status: T - Threatened (legally protected)
- State Rank: S2 - Imperiled
- Global Rank: G5 - Secure
Occurrences
| County Name | Number of Occurrences | Year Last Observed |
|---|---|---|
| Barry | 1 | 1999 |
| Livingston | 1 | 1939 |
| Monroe | 5 | 1985 |
| St. Joseph | 1 | 2006 |
| Washtenaw | 3 | 2002 |
| Wayne | 4 | 2002 |
![Occurrence Map for [Sname]](https://webarchive.library.unt.edu/eot2008/20090116121108im_/http://web4.msue.msu.edu/mnfi/maptmp/NFR_Distributions12321076494776.png)
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
Mostly occurring in large river systems and less commonly in lakes. It is almost always found along muddy banks at the edge of the shore.
Natural Community Types
Associated Plants
Water-plantain, sedges, spike-rush, northern manna grass, cut grass, smartweed, arrowhead, bur-reed, cat-tail, wild rice, water-milfoil, watercress, great duckweed, water-lily, bulrush, pickerel weed, arrow-arum, and pondweed.
Management
Water-willow requires the protection of hydrology. Do not change the course of rivers or add impoundments. Agricultural run-off also likely has negative impacts.
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
- Meander search
Survey Period: From first week of August to fourth week of September
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.
- 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.
- Mohlenbrock, R.H. 1986. Guide to the Vascular Flora of Illinois. Southern Illinois University Press, Carbondale. 507pp.
- 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.