Search Field Guide
Advanced Search
Montana Field Guide

Montana Field Guides

Water Howellia - Howellia aquatilis

Species of Concern

Global Rank: G3
State Rank: S3
* (see State Rank Reason below)

Agency Status
USFWS: LT
USFS: THREATENED
BLM:
MNPS Threat Rank: 2
C-value: 9

External Links






State Rank Reason (see State Rank above)
Water howellia is restricted in Montana to depressional wetlands in the Swan Valley, typically occupying small basins where the water level recedes partially or completely by the Fall. Montana contains the largest number of occupied ponds and wetlands though the total occupied area is small and it is clustered in a small portion of the state, making it vulnerable to localized events and management actions. Reed canary grass (Phalaris arundinacea) has invaded into some wetlands in the Swan Valley and it has the potential to form dense monocultures, thereby decreasing the amount of available habitat, though it has only been found in a small percentage of occupied water howellia sites so far. Additionally, water howellia is an annual species, which is solely dependent on recruitment from seed; and it has very narrow habitat and moisture requirements which leaves it vulnerable to extirpation as a result of consecutive years of unfavorable growing conditions.
  • Details on Status Ranking and Review
    Water Howellia (Howellia aquatilis) Conservation Status Review
    Review Date = 06/11/2012
    View State Conservation Rank Criteria
    Population Size

    Score0-1 - Moderate to Large: Population size is imprecisely known but is believed to be >10,000 individuals.

    CommentSpecies is an annual that apparently has limited seedbanking capabilities. Population levels can fluctuate significantly from year to year depending upon climatic conditions.

    Range Extent

    Score2 - Regional or State Endemic or Small Montana Range: Generally restricted to an area <100,000 sq. miles (equivalent to 2/3 the size of Montana or less) or Montana contributes 50% or more of the species’ range or populations OR limited to 2-3 Sub-basins in Montana.

    CommentGlobal distribution consists of several discontiguous areas. Montana contributes a significant percentage of the global popuations.

    Area of Occupancy

    Score1 - Moderate: Generally occurring in 11-25 Subwatersheds (6th Code HUC’s).

    Environmental Specificity

    Score2 - High: Species is restricted to a highly specialized and limited habitat and is typically dependent upon unaltered, high-quality habitat (C Values of 8-10).

    Trends

    Score0-1 - Stable to Minor Declines:

    CommentTrends are not well-documented, though populations are likely stable or experiencing only minor declines. Large annual fluctuations can occur.

    Threats

    Score1 - Medium: 11-30% of the populations are being negatively impacted or are likely to be impacted by one or more activities or agents, which are expected to result in decreased populations and/or habitat quality and/or quantity.

    Intrinsic Vulnerability

    Score2 - High Vulnerability: Very specific biological attributes, unusual life history characteristics or limited reproductive potential makes the species highly susceptible to extirpation from stochastic events or other adverse impacts to its habitat and very slow to recover.

    Raw Conservation Status Score

    Score 8 to 10 total points scored out of a possible 19.

 
General Description
Water Howellia is a glabrous, much-branched, annual, aquatic herb with fragile, submerged and floating stems that are up to 100 cm tall. The simple, alternate or occasionally opposite or whorled stem leaves are narrowly linear, 1-5 cm long, and entire-margined. Beneath the surface of the water, small flowers that produce seeds without opening are solitary in the leaf axils. Once the stems reach the surface, small, white flowers are borne in a narrow, terminal, leafy-bracted inflorescence. The white corolla is 2-3 mm long. Flowering occurs on the surface of the water. The fruit, which forms below the attachment of the petals, is a capsule that is 1-2 cm long containing elongate seeds that are up to 2-4 mm long.

Phenology
A winter annual which germinates in the Fall, overwinters, and continues growing in the Spring when conditions are favorable. Chasmogamous (flowers that open and allow for pollination) flowers bloom at the surface in late July-early August; the submerged cleistogamous (flowers that do not open and are self-pollinated) flowers begin in late June.

Diagnostic Characteristics
Vegetatively, this species resembles a small-leaved pondweed (Potamogeton) or a water starwort (Callitriche), but the flowers in these two groups lack petals, and they have much smaller seeds.

Species Range
Montana Range

Click the legend blocks above to view individual ranges.
 


Range Comments
Howellia aquatilis is a Pacific Northwest endemic known from northern California (Mendocino Co.) , western Oregon (Benton Co.), Washington (Spokane, Pierce and Thurston Co.), northern Idaho (Latah Co.), and western Montana (Swan Valley) (Mincemoyer 2005).

Summary of Observations Submitted for Montana
Number of Observations: 1211

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Habitat
Small depressional wetlands with consolidated bottoms which partially or completely dry up by the Fall. Vegetation within individual wetlands is most commonly dominated by Carex vesicaria, Typha latifolia, Equisetum fluviatile, Eleocharis palustris and/or Sium suave. These wetlands include shallow, low-elevation glacial pothole ponds and former river oxbows with margins of deciduous trees and shrubs. These habitats are inundated by spring rains and snowmelt runoff and typically dry out by the end of the growing season. The plants tend to root in the shallow water at the edges of deeper ponds that are typically surrounded by deciduous trees.
Predicted Suitable Habitat Model

This species has a Predicted Suitable Habit Model available.

To learn how these Models were created see http://mtnhp.org/models

Ecological Systems Associated with this Species

Ecology
Reproductive Biology and Phenology: Howellia aquatilis is an annual, reproducing entirely by seed. The plant is predominantly a winter annual with germination taking place in the fall and seedlings over-wintering and resuming growth in the spring. Germination of seeds occurs only when ponds dry out and seeds are exposed to air (Lesica 1990, 1992). Thus, the population size in a given year is affected by the extent to which the pond dries out at the end of the previous year. Due in part to this dependence, population size varies widely from year to year. Exceedingly wet years will detrimentally affect population size the next year since seeds will not germinate. Conversely, very dry years may also adversely impact populations if enough water is not present to support a good population and subsequent production of seed. Long-term seed viability is uncertain though it has been shown that seeds lying in the soil longer than eight months have decreased rates of germination and vigor (Lesica 1992). Thus, two or more consecutive years of exceedingly wet conditions or dry conditions may have a severe detrimental impact on population size due to the decreased number of viable seeds. Monitoring data from Montana populations have shown populations rebound after two consecutive years with no plants observed. This provides some evidence that a significant number of seeds remain viable for at least three years, providing a buffer against unfavorable growing conditions in consecutive years.

Water howellia produces both submerged, cleistogamous flowers (flowers that do not open and are self-pollinated) and emergent, chasmogamous flowers (flowers that open and allow for pollination). Studies by Lesica et al. (1988) and Shelly and Moseley (1988) report that self-pollination appears to be the common means of fertilization and that out-crossing, though possible, is probably extremely rare.

Plants begin growth in the spring. Emergent flowers bloom soon after the stems reach the water surface and are present from June into August. Seed dispersal starts in June from submerged flowers and extends until late summer from emergent flowers (USFWS 1996). Spread of seeds by waterfowl or other animals between ponds, though possible, has not been documented. [From Mincemoyer 2005]

References
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Brunsfeld, S.J. and C.T. Baldwin. 1998. Howellia aquatilis genetics: not so boring after all. In: Forum on Research and Management of Howellia aquatilis. Turnbull National Wildlife Refuge, Cheney, WA. March 24-25.
    • Bursick, R.J. 1995. Update: report on the conservation status of Howellia aquatilis in Idaho. Unpublished report. Idaho Department of Fish and Game, Boise. 8 pp.
    • Clegg, M. and A. Lombardi. 2000. Status report for water howellia (Howellia aquatilis) on Fort Lewis, WA. Report to the Land Condition Trend Analysis Program, Fort Lewis, WA. Environment and Engineering Inc., Norfolk, VA. 19 pp.
    • Davis, L. 2004. Flathead National Forest, FY05 – year report of annual monitoring requirements - annual monitoring of water howellia occurrences. Unpublished report. Flathead National Forest, MT.
    • Flathead National Forest Personnel. Howellia aquatilis and Phalaris arundinacea Survey Forms from the U.S. Forest Service 1998-2008 Monitoring Study.
    • Flathead National Forest Personnel. Howellia aquatilis Survey Forms from the U. S. Forest Service 1988-1997 Monitoring Study.
    • Flathead National Forest volunteers. 2000. Swan Ecosystem botany volunteer program coordinated by Maria Mantas.
    • Frissell, C. A., J. T. Gangemi, and J. A. Stanford. 1995. Identifying priority areas for protection and restoration of aquatic biodiversity: A case study in the Swan River basin, Montana, USA. Open File Report No. 136-95. Flathead Lake Biological Station, The University of Montana, Polson. 51 pp.
    • Gamon, J. 1992. Report on the status in Washington of Howellia aquatilis Gray. Washington Natural Heritage Program, Olympia. 46 pp.
    • Gamon, J. 1998. Endangered species management plan for water howellia. Washington Natural Heritage Program, Department of Natural Resources.
    • Gamon, J. 1999. Inventory management plan for water howellia (Howellia aquatilis) on Fort Lewis. Final Reports. Washington Natural Heritage Program, WA Department of Natural Resources in coordination with The Nature Conservancy of Washington.
    • Gamon, J. and T. Rush. 1998. Definition of potential habitat and a monitoring plan for water howellia (Howellia aquatilis) on Fort Lewis. Washington Natural Heritage Program, WA Department of Natural Resources in coordination with The Nature Conservancy o
    • Gilbert, R. 2002. Field report for water howellia surveys on Fort Lewis, WA. Report to the Land Condition Trend Analysis Program, Fort Lewis, WA. Environment and Engineering Inc., Norfolk, VA. 17 pp.
    • Gilbert, R. and A. Lombardi. 1999. Status report for water howellia (Howellia aquatilis) on Fort Lewis, WA. Report to the Land Condition Trend Analysis Program, Fort Lewis, WA. Environment and Engineering Inc., Norfolk, VA. 25 pp.
    • Griggs, F.T. and J.E. Dibble. 1979. Status report, Howellia aquatilis A. Gray. for the Mendocino National Forest. Unpublished report. Mendocino National Forest, CA. 12 pp.
    • Isle, D.W. 1997. Rediscovery of water howellia for California. Fremontia 25(3): 29-32.
    • Jokerst, J.D. 1980. Status report, Howellia aquatilis A. Gray. for the Mendocino National Forest. Unpublished report. California State University, Chico. 18 pp.
    • Lesica, P. 1994. Monitoring Howellia aquatilis at Swan River Oxbow Preserve 1994 Progress Report. Unpublished report to The Nature Conservancy Montana Field Office, Helena, Montana. 5 pp.
    • Lesica, P. 1995. Monitoring Howellia aquatilis at Swan River Oxbow Preserve 1995 Progress Report. Unpublished report prepared for The Nature Conservancy Montana Field Office, Helena, Montana. 4 pp.
    • Lesica, P. 1990. Habitat requirements, germination behavior and seed bank dynamics of Howellia aquatilis in the Swan Valley, Montana. Unpublished report to the Flathead National Forest. Conservation Biology Research, Helena, Montana. 44 pp. plus appendix.
    • Lesica, P. 1991. Monitoring Howellia aquatilis and Phalaris arundinacea at Swan River Oxbow Preserve. Progress report. The Nature Conservancy, Helena, Montana. 7 pp.
    • Lesica, P. 1992. Autecology of the endangered plant Howellia aquatilis: Implications for management and reserve design. Ecological Applications 2(4):411-421.
    • Lesica, P. 1994. Monitoring Howellia aquatilis at Swan River Oxbow Preserve: 1993 progress report. Unpublished report prepared for the Montana Nature Conservancy, Helena. 5 pp.
    • Lesica, P. 1996. Monitoring Howellia aquatilis at Swan River Oxbow Preserve; 1994 Final Report. Report to The Nature Conservancy, Montana Field Office, Helena, MT. 6 pp.
    • Lesica, P. 1997. Spread of Phalaris arundinacea adversely impacts the endangered plant Howellia aquatilis. Great Basin Naturalist, 57(4): 366-368.
    • Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
    • Lesica, P., R.F. Leary and F.W. Allendorf. 1987. Lack of genetic diversity within and among populations of the rare plant Howellia aquatilis. Unpublished report, submitted to The Nature Conservancy, Helena, Montana. 15 pp.
    • Lesica, P., R.F. Leary, F.W. Allendorf, and D.E. Bilderback. 1988. Lack of genetic diversity within and among populations of an endangered plant, Howellia aquatilis. Conservation Biology 2: 275-282.
    • Lichthardt, J. and K. Gray. 2001. Monitoring of Howellia aquatilis (water howellia) and its habitat at the Harvard-Palouse River Flood Plain Site, Idaho: Third-year results. Idaho Department of Fish and Game, Idaho Conservation Data Center, Boise, ID. 8 p
    • Lichthardt, J. and K. Gray. 2003. Monitoring of Howellia aquatilis (water howellia) and its habitat at the Harvard-Palouse River Flood Plain Site, Idaho: Fourth-year results. Idaho Department of Fish and Game, Idaho Conservation Data Center, Boise, ID. 8
    • Lichthardt, J. and K. Gray. 2005. Monitoring of Howellia aquatilis (water howellia) and its habitat at the Harvard-Palouse River Flood Plain Site, Idaho: Fifth-year results. Idaho Department of Fish and Game, Idaho Conservation Data Center, Boise, ID. 10
    • Lichthardt, J. and R. Moseley. 2000. Ecological assessment of Howellia aquatilis habitat at the Harvard-Palouse River flood plain site. Boise, ID. Unpublished report. Prepared for the Idaho Department of Parks and Recreation by the Idaho Department of Fis
    • Mantas, M. 1998. Historical vs. current conditions of upland forests surrounding Howellia aquatilis habitats in the Swan Valley, MT. In: Forum on Research and Management of Howellia aquatilis. Turnbull National Wildlife Refuge, Cheney, WA. March 24-25.
    • Mantas, M. 2000. Status of Water Howellia (Howellia aquatilis) and Reed Canarygrass (Phalaris arundinacea) in Water Howellia Ponds: 1998 and 1999, Swan Valley, Montana.
    • Mantas, M. 2002. Status of water howellia (Howellia aquatilis) and reed canarygrass (Phalaris arundinacea) in water howellia ponds: 1998-2001. Flathead National Forest, MT.
    • McCarten, N. and R. Bittman. 1998. Water chemistry, nutrient cycling, productivity and environmental factors affecting plant community structure in Howellia aquatilis ponds. In: Forum on Research and Management of Howellia aquatilis. Turnbull National Wil
    • McCune, B. 1982. Noteworthy collections - Montana: Howellia aquatilis. Madrono 29:123-124.
    • Mincemoyer, S. 2005. Range-wide status assessment of Howellia aquatilis (water howellia). Prepared for the U.S. Fish and Wildlife Service. Montana Natural Heritage Program, Helena, MT. 21 pp. + appendices.
    • Reeves, D.M. 2001. Hydrologic controls on the survival of water howellia (Howellia aquatilis) and implications of land management, Swan Valley, Montana. Master's Thesis, University of Montana. 222 pp.
    • Rice, D.J. 1989. Short-term protection of Howellia aquatilis: East Pond study area, Dishman Hills Natural Resource Conservation Area, Spokane, WA. Report to Department of Natural Resources. 13 pp.
    • Rice, D.J. 1990. An application of restoration ecology to the management of an endangered plant, Howellia aquatilis [M.S. thesis]. Washington State Univ., Pullman, WA. 85 pp.
    • Roe, L.S. and J.S. Shelly. 1992. Update to the status review of Howellia aquatilis: field surveys, monitoring studies and transplant experiments. Report to the USDA Forest Service, Flathead National Forest. Montana Natural Heritage Program, Helena, MT. 51
    • Roe, L.S. and J.S. Shelly. 1992. Update to the status review of Howellia aquatilis: field surveys, monitoring studies, and transplant experiments. Unpublished report to the Flathead National Forest. Montana Natural Heritage Program, Helena, MT 51 pp.
    • Schassberger, L. A., and J. S. Shelly. 1991. Update to the status review of Howellia aguatilis, field surveys, monitoring studies, and transplant experiments. Unpubl. Rep., Flathead National Forest and Montana Natural Heritage Program, Helena. 57 pp.
    • Schassberger, L.A. and J.S. Shelly. 1991. Update to the status review of Howellia aquatilis: field surveys, monitoring studies, and transplant experiments. Prepared for the USDA Forest Service, Flathead National Forest. Montana Natural Heritage Program, Helena, MT 57 pp.
    • Shapley, M. 1998. Field chemistry and basin geomorphology of Montana’s Howellia aquatilis ponds (Abstract). In: Forum on Research and Management of Howellia aquatilis. Turnbull National Wildlife Refuge, Cheney, WA. March 24-25.
    • Shapley, M. 1998. Preliminary evaluation of basin morphology and field chemistry of Montana's Howellia aquatilis ponds. Prepared for Flathead National Forest and the U.S. Fish and Wildlife Service. 7pp. plus appendices.
    • Shapley, M. and P. Lesica. 1997. Howellia aquatilis (Water Howellia) ponds of the Swan Valley: conceptual hydrologic models and ecological implications. Unpublished report to the U. S. Fish and Wildlife Service. Montana Natural Heritage Program and Conservation Biology Research. Helena 44 pp.
    • Shelly, J. S. 1988. Conservation status of Howellia aguatilis, a candidate threatened species. Unpubl. Rep., USDI Fish and Wildlife Service, Denver, CO. 166 pp.
    • Shelly, J.S. 1988. Distribution and status of Howellia aquatilis A. Gray (Campanulaceae) in Lake and Missoula Counties, Montana. Proceedings of Montana Acadamy Science. 48:12. (Abstract)
    • Shelly, J.S. 1988. Report on the conservation status of Howellia aquatilis, a candidate threatened species. Unpublished report to the U.S. Fish and Wildlife Service, Denver. Montana Natural Heritage Program, Helena, MT 166 pp.
    • Shelly, J.S. 1988. Status review of Howellia aquatilis, U.S. Forest Service, Region 1, Flathead National Forest. Unpublished report. Montana Natural Heritage Program, Helena, MT 120 pp.
    • Shelly, J.S. 1989. Addendum to the status review of Howellia aquatilis, USDA Forest Service, Region 1, Flathead National Forest, Montana. Unpublished report to the U.S. Forest Service, Region 1. Montana Natural Heritage Program, Helena, MT 17 pp.
    • Shelly, J.S. 1994. Conservation strategy, Howellia aquatilis, Flathead National Forest. Unpublished report. USDA Forest Service, Northern Region 26 pp.
    • Shelly, J.S. 1995. Howellia aquatilis: Montana's first federally listed plant species. Kelseya, Newsletter of the Montana Native Plant Society.
    • Shelly, J.S. 1997. Conservation strategy, Howellia aquatilis, Flathead National Forest (second edition). Unpublished report. USDA Forest Service, Northern Region 24 pp.
    • Shelly, J.S. 1998. Howellia aquatilis – ten years of monitoring, Swan Valley, MT. In: Forum on Research and Management of Howellia aquatilis. Turnbull National Wildlife Refuge, Cheney, WA. March 24-25.
    • Shelly, J.S. 1998. Translocation experiments, Swan Valley, MT. In: Forum on Research and Management of Howellia aquatilis. Turnbull National Wildlife Refuge, Cheney, WA. March 24-25.
    • Shelly, J.S. 2015. Draft Monitoring Report for Howellia aquatilis. US Forest Service, Region 1, Missoula, Montana.
    • Shelly, J.S. and J. Gamon. 1996. Howellia aquatilis (Water Howellia) recovery plan. Unpublished report to the U. S. Fish and Wildlife Service. vi. plus 52 pp.
    • Shelly, J.S. and L.A. Schassberger. 1990. Update to the status review of Howellia aquatilis: field surveys, monitoring studies, and transplant experiments, 1989. Unpublished report to the Flathead National Forest, Kalispell, MT. Montana Natural Heritage Program, Helena, MT 50 pp.
    • Shelly, S. 1995. Eccentric aquatic. Reprinted in the Conservationist's Notebook feature of American Horticulturalist 74(11):11.
    • The Nature Conservancy Personnel. Howellia aquatilis and Phalaris arundinacea Survey Forms from The Nature Conservancy's 2009-2012 Monitoring Study.
    • U.S. Fish and Wildlife Service. 1993. Endangered and threatened wildlife and plants; Proposed listing of water howellia (Howellia aquatilis) as threatened. Federal Register 58(72): 19795-19800.
    • U.S. Fish and Wildlife Service. 1994. Endangered and Threatened wildlife and plants; the plant, Water howellia (Howellia aquatilis), determined to be a Threatened species. 50 CFR Part 17. Federal Register 59(134):35860-35864.
    • U.S. Fish and Wildlife Service. 1996. Water howellia (Howellia aquatilis) recovery plan, public and agency review draft. Report to the U.S. Fish and Wildlife Service. 52 pp.
    • USDA Forest Service. 1994. Conservation strategy for Howellia aquatilis A. Gray. USDA Forest Service, Flathead National Forest. 26 pp.
    • USDA Forest Service. 1997. Conservation strategy for Howellia aquatilis A. Gray (second edition). USDA Forest Service, Flathead National Forest. 24 pp.
    • Washington Natural Heritage Program. 2005. WA Natural Heritage Information System - March 2, 2005. Olympia, WA.
    • Woessner, W. W. and B. Heidel. 1999. Progress Report 7/99-11/99. Preserving the function of unique wetlands critical to survival of water howellia in the Swan Valley, Montana. Report prepared for the Montana Department of Environmental Quality.
    • Wolfold, L. 2003. Water howellia monitoring on Fort Lewis, 2003. Report to the Land Condition Trend Analysis Program, Fort Lewis, WA. Environment and Engineering Inc., Norfolk, VA. 17 pp.
    • Wolfold, L. 2004. Water howellia (Howellia aquatilis) monitoring on Fort Lewis Military Reservation field report, 2004. Report to the Land Condition Trend Analysis Program, Fort Lewis, WA. Environment and Engineering Inc., Norfolk, VA. 22 pp.
  • Web Search Engines for Articles on "Water Howellia"
  • Additional Sources of Information Related to "Dicots"
Login Logout
Citation for data on this website:
Water Howellia — Howellia aquatilis.  Montana Field Guide.  .  Retrieved on , from