Vascular Flora of Arend's Kettle, Freda Haffner Kettlehole State Preserve, Dickinson County, Iowa

Journal of the Iowa Academy of Science: JIAS

Volume 98 Number Article 16

1991

Edwin L. Freese University of Northern Iowa

William J. Platt Louisiana State University

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Recommended Citation Freese, Edwin L. and Platt, William J. (1991) "Vascular Flora of Arend's Kettle, Freda Haffner Kettlehole State Preserve, Dickinson County, Iowa," Journal of the Iowa Academy of Science: JIAS, 98(2), 102-107. Available at: https://scholarworks.uni.edu/jias/vol98/iss2/16

This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Journal of the Iowa Academy of Science: JIAS by an authorized editor of UNI ScholarWorks. For more information, please contact [email protected]. ]our. Iowa Acad. Sci. 98(2): 102-107, 1991

Vascular Flora of Arend's Kettle, Freda Haffner Kettlehole State Preserve, Dickinson County, Iowa

EDWIN L. FREESE 1 and WILLIAM J. PLATT

Department of Biology, University of Northern Iowa, Cedar Falls, IA 50613 and Department of Botany, Louisiana State University, Baton Rouge, LA 70803

Arend's Kettle is a 5 ha glacial landform in Dickinson County, Iowa. The flora of this kettle was studied over two years prior to acquisition by the Nature Conservancy in 1973. The known vascular flora of Arend's Kettle as of 1973 consisted of 299 species, representing 177 genera and 59 families. The vegetation ranged from xeric short grass prairie along the rims of the kettle to mesic prairie along the middle and lower slopes. In the bottom of the kettle, there was a marsh/seasonal pond community that varied greatly in the amount of water present, depending on rainfall within the 30 ha drainage into the kettle. At the time of this study, cattle grazing was occurring in the kettle, and there was a prominent' ruderal flora associated with trails running along the rims and down to the bottom of the kettle. The shoreline of the marsh also was frequently disturbed by cattle. One federally and state threatened species, Lespedeza leptostachya, prairie bush clover, and one state threatened species, Asdepias lanuginosa, wooly milkweed, were present on the site. Two species were added to the Dickinson County flora. INDEX DESCRIPTORS: Arend's Kettle, Freda Haffner Kettlehole State Preserve, Iowa flora, prairie, Lespedeza leptostachya, Asdepias lanuginosa, Dickinson County.

Arend's Kettle in northwestern Iowa is widely known as an (Shaw and Waite 1964). Dickinson county weather is coldest in exemplary kettle (Salisbury and Knox 1969). This unique geological January ( - 9°C average), warmest in July (23°C average). feature, about 5 hectares (12.4 acres) in size (Gerhardt 1940; Collins Formation of the large kettle occurred during the Wisconsin 1968), is located in the Freda Haffner Kettlehole State Preserve, a period of glaciation (Salisbury and Knox 1969). A large block of ice 44. 5 ha preserve managed by the Iowa Chapter of The Nature melted, and glacial till was deposited around the edges, forming the Conservancy. This preserve is located in Dickinson County, Iowa, rim of the kettle. Arend's kettle is located near the Altamont terminal about 5 km west of West Lake Okoboji. glacial moraine (about 2 km west). The ridge on which Arend's kettle In this paper, we present a species list of vascular plants for Arend's is located appears to be an esker deposited by the Little Sioux River Kettle that was compiled over two growing seasons just prior to carrying glacial runoff under the ice sheet. Radiocarbon dating of acquisition by The Nature Conservancy in 1973. The preserve was cores taken by Collins (1968) establish kettle formation at more than grazed by cattle during the period of study. The cattle cropped the 12,400 years before present. vegetation where they grazed, and they created trails running from the rims down to the marsh at the bottom of the kettle. The wet METHODS prairie and marsh at the bottom of the kettle were frequently disturbed by cattle coming down to drink and graze. Since 1973, Collections were made from the rim and interior of the kettle (a 5 grazing has ceased, and prescribed fires have been used for manage ha area) over two periods: June to September 1972 and March to ment of the preserve. The species list and general locations of species November 1973. Specimens of vascular plants were located and of plants within the preserve in the early 1970s thus should provide identified. A majority of these were collected as vouchers, which have data useful in documenting changes occurring after establishment of been deposited in the herbarium at the University of Northern Iowa. this preserve. Nomenclature follows Gleason and Cronquist (1963) and updates on classification and synonomy made by Roosa et al. (1989). Pohl (1966) was used for Poaceae. Exceptions are as follows: (1) Potamo STUDY AREA getanaceae and Cannabinaceae are treated as separate families; (2) Arend's Kettle is located in the southeast quarter of the northwest Artemisia caudata is considered a distinct species; (3) Mirabilis is quarter of Section 33, Lakeville Township, Tier 99 North, Range 37 considered a distinct genus; (4) Penthorum is included in Saxifraga West, Dickinson county, Iowa. It is situated on the east bluff of the ceae; and (5) Lobelia is included in Campanulaceae. Little Sioux River floodplain, which at this location is a broad, U shaped trough. The kettle watershed is 29.6 hectare (73.1 acres). The RESULTS AND DISCUSSION highest point on the kettle rim is 447 meters (1465 feet) above sea level (Gerhardt 1940). The surface of the pond is at 427 meters ( 1400 An annotated checklist of vascular plants collected from Arend's feet), producing a 20 m difference in elevation from rim to floor of the kettle is presented in Appendix I. Families, genera and species are kettle. Kettle slopes are steep (30-45°). The widest rim to rim dis listed alphabetically. Habitats refer to environmental conditions tance is 322 meters (1056 feet), and the narrowest is 181 meters (594 occurring along the slopes of the kettle. Relative frequency of feet). The marsh (0.1 hectare, 0.26 acre) in the center of the kettle occurrence was based on personal field observations and collections varies in depth from dry to 2 meters depending on rainfall (Collins within each habitat. "Abundant" indicates occurring in large num 1968). The seasonal pond in the center of the marsh has never been bers or very evident. "Common" indicates many speciments or known to overflow the rim of the kettle and has no known springs. locations. "Frequent" indicates 11-20, and "infrequent" denotes 6-10 Soil types are of the Dickinson, Clarion, and Pierce series (Soil Survey occurrences. A species was considered "rare" if only 1-5 locations were of Iowa 1923). Average yearly precipitation for the county is 686 mm made. Flowering times were noted for most species and are indicated as that span of time over which flowers were observed in the field. A total of 276 species and 173 genera, representing 57 families, 1Current Address: 515 Y2 2nd Sc., S.E., Waverly, Iowa 50677 were identified during our collections made in 1972 and 1973. Only VASCULAR FLORA OF AREND'S KETTLE 103

one pteridophyte was collected. The monocots consisted of 13 (e.g., Helianthus grosseserratus, Silphium perfoliatum, Silphium lacinia families, 48 genera, and 83 species, while dicots consisted of 43 tum, Panicum implicatum, Panicum scribnerianum, Viola pedata, Cuscuta families, 121 genera, and 192 species, The four largest families are: glomerata, Fragaria vesca, Physalis pruinosa, Tragopogon pratemis, Apocy Asteraceae, 51 species; Poaceae, 46 species; Fabaceae, 22 species; num cannabinum, and Thalictrum revolutum) may have been eliminated Cyperaceae, 17 species. by grazing, while others may have succumbed to trampling and Three habitats present in the kettle included dry prairie rim, mesic grazing of the marsh edges (Typha latifolia, Scirpus validus, Carex com slopes, and marsh, Typical short-grassland species occupied the kettle munis, Carex vulpinoidea, and Polygonum natans). Some species are rim. The most abundant species included Bouteloua gracilis, Poa possibly misidentified (e.g., Oxalis dilleni and Tradescantia subaspera). pratensis, Schizachyrium scoparium, Amorpha canescens, Ambrosia arte A search through the Iowa Lakeside Laboratory Herbarium re misiifolia, Panicum praecocius, Achillea millefolium, Bouteloua hirsuta, vealed many specimens collected from Arend's kettle. One species, Solidago missouriensis, and Carex brevior. Other representative species Panicum philadelphicum (Grant 8904) is listed as threatened in Iowa, were Anenome patens, Echinacea pallida, Koeleria cristata, Psoralea esculen but was not located during the current study. The earliest collected ta, Aster sericeus, Allium stellatum, and Astragalus crassicarpus. Oxytropis specimen from the kettle was Agalinis (Gerardia) aspera (B. Shimek, lambertii and Androsace occidentalis also occupied dry sandy knobs. 1794, August 24, 1919. . Tall grass prairie dominated the mesic slopes. Dominant grasses Lespedeza leptostachya, prairie bush clover, is listed as a threatened and composites included Poa pratensis, Ambrosia artemisiifolia, An plant by the U.S. Department of Interior's endangered and threatened dropogon gerardii, Schizachyrium scoparium, Bouteloua curtipendula, Achil species listing ( 1987). Plants were located on the southeast slope. lea millefolium, Solidago canadensis, Panicum praecocius, Stipa spartea, Asclepias lanuginosa, wooly milkweed, is listed as threatened in Iowa. Panicum oligosanthes, and Cirsium undulatum. Other important species Scattered plants were present near the kettle rim. were Verbena stricta, Asclepias verticillata, Trifolium procumbens, Onos Two new species were added to the Dickinson county flora: modium molle, Dalea purpureum, Heliopsis helianthoides, Medicago lupuli Androsace occidentalis and Geum triflorum. The most recent updates of na, Lithospermum incisum, Monarda fistulosa, Potentilla arguta, and the county flora were those of Martin L. Grant (1951, 1953). Scirpus Erigeron strigosus. Many other typical tall grass species, for example, heterochaetus was not reported by Grant, but was included in the Asclepias tuberosa, Ceanothus americanus, and Brickellia eupatoroides, were Cayler Prairie flora by Aikman & Thorne ( 1956). present in lesser numbers. Van Der Valk and Davis (1976) conducted an ecological survey of The marsh contained two zones. The outer zone was a wet prairie the kettle marsh vegetation during the 1973 and 1975 growing that ranged from moist soil to standing water. Typical dominant seasons. Plants were sampled by clipping along two permanent species were Glyceria grandis, Polygonum hydropiper, Lysimachia hybrida, transects located perpendicular to shoreline. They reported 30 species Leersia oryzoides, Iris versicolor, Ambrosia artemisiifolia, Carex meadii, of vascular plants comprising 19 families and 26 genera. Of these 15 Scutellaria latiflora, Menta arvensis, Alopecurus aequalis, Sium suave, were monocots and 15 were dicots. Three species, Beckmannia Bidens cernua, Eleocharis acicularis, and Hypericum majus. In each of the syzigachne, Carex rostrata, and Polygonum coccineum, were not located two years studied, plants of the inner marsh zone were in standing during our search. Eleocharis palustris also was collected and may be water most of the growing season. There were fewer species present as synonomous with Eleocharis erythropoda (Gleason & Cronquist 1963) well. Dominant species were Sagittaria latifolia, Scirpus heterochaetus, and Eleocharis macrostachya of Grant (1951, 1953). Differences in and Sparganium eurycarpum. Two other abundant species, Lemna minor species composition of the flora in the kettle marsh between the and Spirodella polyrhiza, were species that floated on the pond surface. 1970-1972 and 1973-1975 seasons may reflect marked year to year The seasonal pond also supported a lush growth of submerged aqua changes in water levels, as well as the timing of precipitation during tic plants. Potamogeton foliosus, Potamogeton pus illus, Ceratophyllum demer the growing season. sum and Naius f/exilis were the most abundant species. Yellow flowered bladderwort, Utricularia vulgaris, dotted the surface throughout the ACKNOWLEDGEMENTS summer. Ruderal species were quite evident in the kettle. Cowpaths were We thank the Iowa Chapter of The Nature Conservancy for most evident along the ridge top, descending the slopes at an angle allowing the use of the Freda Haffner Kettlehole State Preserve for on the southeastern and western sides, and encircling the marsh. A this study. Iowa Lakeside Laboratory and Dr. Richard V. Bovbjerg well-worn path led to a watering strip at the western pond edge. The provided logistic support for this study. Portions of this study were kettle slopes were grazed, although not heavily. Plants of weedy conducted with the assistance of MacBride Scholarships at Iowa species were located throughout the kettle, but were especially Lakeside Laboratory. Dr. Larry]. Eilers and Michael Weis aided in noticeable along paths of mid to lower slope. Most abundant were identification of species. Also thanks to Glenn H. Crum who helped ragweed, Ambrosia artemisiifolia; yarrow, Achillea millefolium; mock identify aquatic plants. pennyroyal, Hedeoma hispida; vervain, Verbena stricta; spurge, Euphor bia glyptosperma; low hop clover, Trifolium campestre, black medic, REFERENCES Medicago lupulina; yellow foxtail, Setaria lutescens; daisy fleabane, Erigeron strigosus; yellow wood-sorrel, Oxalis stricta. A few scattered AIKMAN,J.M. and R.F. THORNE. 1956. The Cayler Prairie: an ecologic and taxonomic study of a northwest Iowa prairie. Proc. Iowa Acad. Sci. clones of Canada thistle, C irsium arvense, were present on the southern 63:177-200. slope. COLLINS, G.B. 1968. Implications of diatom succession in post-glacial Woody plants were scattered throughout the kettle. U Imus pumila, sediments from two sites in northern Iowa. Ph.D. Thesis. Iowa State Crataegus mollis, and Prunus americana occurred in small numbers. University, Ames, Iowa. Populus deltoides and Salix amygdaloides invaded the cattle watering GERHARDT, C.E. 1940. An ecological survey of a large kettle hole. M.S. strip on the west side of the marsh during 1973. Several small clumps Thesis. University of Iowa, Iowa City. GLEASON, H.A. and A. CRONQUIST. 1963. Manualofvascularplantsof of Symphoricarpos occidentalis were present on the southeast slope. northeastern United States and adjacent Canada. D. Van Nostrand Co., Gerhardt ( 1940) sampled the kettle flora. He reported 96 species New York. 810 p. of vascular plants, 90 from permanent quadrats and discussed 6 more, GRANT, M.L. 1951. Dickinson County flora. Proc. IowaAcad. Sci. 57:91- representing 74 genera and 35 families. Although we searched the 129. entire kettle carefully, we did not locate 19 species, including some -----· 1953. Additions to and notes on the flora of Dickinson prominent prairie and marsh species. A number of these species, County, Iowa. Proc. Iowa Acad. Sci. 60: 131-140. 104 JOUR. IOWA ACAD. SCI. 98(1991)

POHL, R.W. 1966. The grasses of Iowa. IowaStateJour. Sci. 40:341-573. U.S. Department of Agriculture, Bureau of Soils. 1923. Soil survey of ROOSA, D.M., L.J. EILERS, and M.J. LOOSEHKE. 1989. Distribution Dickinson County, Iowa: U.S. Government Printing Office, Washing of Iowa's endangered and threatened vascular plants. Iowa Department of ton, 40 p. Natural Resources, Des Moines, Iowa. 107 p. U.S. Department of the Interior, Fish and Wildlife Service. 1987. En SALISBURY, N.E. and J.C. KNOX. 1969. Glacial landforms of the big dangered and threatened species: plants. Federal Register. 52(6):781- kettle locality, Dickinson County, Iowa. Development Series Report 6. 785. Iowa State Preserves Advisory Board, Iowa City, 11 p. VAN DER VALK, A.G. and C.B. DAVIS. 1976. Changes in the composi SHAW, R.H. and P.J. WAITE. 1964. The climate of Iowa. III. Monthly, tion, structure, and production of plant communities along a perturbed crop season and annual temperatures and precipitation normals for Iowa. wetland coenocline. Vegetatio 32:87c96. Iowa State Univ. Ag. Home Exp. State. Special Report 38. 32 pp.

Annotated Checklist of Vascular Plants Arend's Kettle Freda Haffner Preserve, Dickinson County, Iowa

Division Pteriodophyta Eleocharis acicularis (L.) R. & S. Spike-rush. Marsh Agrostis scabra Willd. Ticklegrass. Dry to mesic and shallow water; abundant; May-August. prairie; common; May-August. Equisetaceae (Horsetail Family) Eleocharis erythropoda Steud. Spike-rush. Marsh Alopecurus aequa/is Sobol. Short-awn foxtail. Equisetum laevigatum A. Br. Prairie scouring rush. and shallow water; common; May-July. Moist prairie to shallow water; common; Dry to mesic prairie; common; June. Scirpus atrovirens Willd. Bulrush. Marsh; fre June-August. Division Spermatophyta quent; June-July. Andropogon gerardii Vitm. Big blue stem. Dry to Class Angiospermae Scirpus fluviatilus (Torr.) Gray. River bulrush. mesic prairie; abundant; August-September. Marsh to shallow water; common; June-July. Aristida basiramea Engelm. Three-awn. Dry Subclass Monocotyledoneae Scirpus heterochaetus Chase. Great bulrush. Shallow prairie; frequent; August-October. Alismataceae (Water-plantain Family) water; abundant locally; June-July. Beckmannia syzigachne (Steud.) Fern. Sloughgrass. Alisma subcwdatum Raf. Water-plantain. Shallow Scirpus validus Vahl. Great bulrush. (Gerhardt (Van der Valk and Davis 1976). marsh; abundant; July-August. 1940). Bouteloua curtipendu/a (Michx.) Torr. Side-oats Sagittaria latifolia Willd. Broad-leaved arrow Hydrocharitaceae (Frog's-bit Family) grama. Dry to mesic prairie; abundant;June head. Shallow marsh; abundant;July-August. Vallisneria americana Michx. Tape-grass. Open September. Amaryllidaceae (Amaryllis Family) water; rare. Bouteloua gracilis (HBK) Lag. Blue grama. Dry prairie; common; July-August. Hypoxis hirsuta (L.) Cov. Star grass. Mesic to wet Iridaceae (Iris Family) prairie; infrequent; April-July. Bouteloua hirsuta Lag. Hairy grama. Dry prairie; Iris versico/or L. Blue flag. Wet prairie and marsh; common; July-August. Commelinaceae (Spiderwort Family) abundant; May-July. Bromus inermis Leyss. Smooth brome. Mesic Tradescantia bracteata Small. Spiderwort. Mesic Sisyrinchium campestre Bickn. Blue eyed grass. Dry prairie; infrequent; weed; June-July. prairie; infrequent; June-July. to mesic prairie; abundant; April-June. Bromus japonicus Thunb. Japanese brome. Dry Tradescantia ohioensis Raf. Spiderwort. Dry prairie; Juncaceae (Rush Family) prairie and disturbed areas; infrequent weed; infrequent; June-July. juncus dudleyi Wieg. Rush. Wet prairie; infre June-July. Tradescantia subaspera Kev. Spiderwort. (Gerhardt quent; June-August. Calamagrostis canadensis (Michx.) Beauv. Blue 1940). Lemnaceae (Duckweed Family) joint. Marsh; infrequent; June-July. Cyperaceae (Sedge Family) Lemna minor L. Duckweed. Abundant in shallow Calamagrostis inexpansa A. Gray. Bluejoint. Cam: atherodes Spreng. Sedge. Shallow marsh; pond. Marsh; rare; June-July. abundant locally; June-July. Spirodella polyrhiza (L.) Schleid. Duckweed. Echinochloa crusgalli (L.) Beauv. Barnyard grass. Cam: bebbii (Bailey) Fern. Sedge. Wet prairie to Abundant in shallow pond. Disturbed areas; frequent; July-September. marsh; infrequent. Wo/ffia punctata Griseb. Duckweed. Rare in shal Elymus canadensis L. Wild rye. Mesic-wet prairie; Cam: bicknellii Britt. Sedge. Dry to wet prairie; low pond. frequent; July-August. common; May-July. Eragrostis cilianensis (All.) E. Masher. Stink grass. Cam: breviw (Dewey) Mackenzie. Sedge. Dry to Liliaceae (Lily Family) Weed along paths; infrequent; June-Septem mesic prairie; abundant; May-July. Allium stellatum Nutt. Prairie onion. Dry to ber. Cam: crmzmunis Bailey. Sedge. (Gerhardt 1940). mesic prairie; abundant; July-September. Glyceria grandis S. Wars. Manna grass. Shallow Carex e/eocharis Bailey. Sedge. Dry prairie; abun Smilacina stellata (L.) Desf. False Solomon's seal. marsh; abundant; May-June. dant locally; May-June. Mesic sandy prairie (local); rare; May-June. Hierochloe odoratoa (L.) Beauv. Holy grass. Mesic Carex gravida Bailey. Sedge. Wet prairie to Zygadenus e/egans Pursh. Death camas. Dry to wet prairie; rare; April-June. marsh; common; June-July. mesic prairie; infrequent; June-July. Hordeum jubatum L. Squirrel tail barley. Mesic Carex lasiocarpa Ehrh. Sedge. Wet prairie to wet prairie and marsh; common; May-July. marsh; common; May-July. Najadaceae (Naid Family) Koeleria cristata (L.) Pers. June grass. Dry prairie; Carex meadii Dewey. Sedge. Mesic prairie to Najas flexi/is (Willd.) Rostk. & Schmidt. Naiad. common; May-July. marsh; abundant; May-July. Abundant in open water. Leersia oryzoides (L.) Sw. Rice cut grass. Wet Cam: praegracilis W. Boott. Sedge. Marsh; abun Poaceae (Grass Family) prairie to shallow marsh; common; July dant locally; June-July. Agropyron repens (L.) Beauv. Quack grass. Disturb September. Cam: rostrata Stokes. Sedge. Marsh (Van der Valk ed prairie; infrequent; June-July. Muhlenbergia cuspidata (Torr.) Rydb. Muhly grass. and Davis 1976). Agropyron smithii Rydb. Wheat grass. Dry to Dry prairie; frequent; July-September. Cam: stricta Lam. Sedge. Wet prairie to marsh; mesic prairie; common; June-July. Muhlenbergia mexicana (L.) · Trin. Muhly grass. abundant (locally); May. Agropyron trachycau/um (Link) Maire. Slender Wet prairie and marsh; infrequent; July Cam: sychnocepha/a Carey. Sedge. Wet prairie to wheatgrass. Dry to mesic prairie; common; October. marsh; common; June-August. June-August. Panicum capillare L. Witch grass. Disturbed areas; Cam:vulpinoidea Michx. Sedge. (Gerhardt 1940). Agrostis alba L. Redtop. Wet prairie; frequent; infrequent; July-September. Cyperus odoratus L. Moist prairie to marsh; com June-July. Panicum implicatum Scribn. (Gerhardt 1940). mon; July-August. VASCULAR FLORA OF AREND'S KETTLE 105

Panicum leibergii (Vasey) Scribn. Dry to mesic Apocynaceae (Dogbane Family) Cirsium undulatum (Nutt.) Spreng. Thistle. Dry prairie; infrequent; May-July. Apocynum cannabinum L. Indian hemp. (Gerhardt to mesic prairie; common; June-September. Panicum oligosanthes Schult. Dry to mesic prairie; 1940). Cirsium vulgare (Savi.) Tenore. Bull thistle. Mesic abundant; May-August. Apocynum sibiricum Jacq. Dogbane. Mesic prairie; prairie; frequent; June-October. Panicum philadelphium Bernh. (Grant 1951). infrequent; June-July. Conyza canadensis (L.) Cronq. Horseweed. Dry to Panicum praecocius Hitchc. & Chase. Dry to mesic Asclepiadaceae (Milkweed Family) mesic prairie; common; July-November. prairie; abundant; May-August. Asclepias hirtella (Pennell) Woodson. Tall green Coreopsis palmata Nutt. Stiff coreopsis. Dry to Panicum scribnerianum Nash. (Gerhardt 1940). milkweed. Dry prairie; frequent; June mesic prairie; frequent; June-July. Panicum virgatum L. Switch grass. Mesic prairie; August. Echinacea pa/Iida Nutt. Pale purple coneflower. frequent; July-September. Asclepias lanuginosa Nutt. Wooly milkweed. Dry Dry prairie; common; May-August. Panicum wilcoxianum Vasey. Dry prairie; infre prairie; infrequent; June-August. Erigeron strigosus Muhl. Daisy fleabane. Dry to quent; May-July. Asclepias ovalifolia Dene. Oval milkweed. Mesic mesic prairie; abundant; June-September. Phalaris arundinacea L. Reed canary grass. Wet prairie; rare; June-July. Euthamia graminifolia (L.) Nutt. Lance-leaved prairie and marsh; frequent; June-August. Asclepias syriaca L. Common milkweed. Mesic goldenrod. Mesic to wet prairie; infrequent; Ph/eum pratense L. Timothy. Mesic-wet prairie and prairie; infrequent; June-August. July-October. cowpaths; common; June-August. Asclepias tuberosa L. Butterfly weed. Mesic prairie; Helianthus grosseserratus Martens. Saw-toothed Poa compressa L. Canada blue grass. Dry prairie; infrequent; June-August. sunflower. (Gerhardt 1940). common; June-July. Asclepias verticillata L. Whorled milkweed. Dry to Helianthus rigidus (Cass.) Desf. Showy sunflower. Poa palustris L. Wet prairie and marsh; common; mesic prairie; common; June-August. Dry to mesic prairie; frequent; August-Sept June-August. Asclepias viridif/ora Raf. Green milkweed. Dry ember. Poa pratensis L. Kentucky blue grass. Dry prairie prairie; infrequent; July-August. Heliopsis helianthoides (L.) Sweet. Ox-eye. Mesic to marsh; abundant; May-July. prairie; infrequent; June-August. Schizachyrium scoparium (Michx.) Nash. Little blue Asteraceae (Composite Family) Lactuca ludoviciana (Nutt.) Ridd. Prairie lertuce. stem. Dry to mesic prairie; abundant; Au Achillea millefolium L. ssp. lanulosa (Nutt.) Piper. Dry to mesic prairie; infrequent;] uly-Septem gust-September. Yarrow. Dry to mesic prairie; abundant;June ber. Setaria lutescens (Weigel) F.T. Hubb. Yellow fox November. Lactuca serriola L. Prickly lettuce. Mesic prairie; tail. Dry prairie to marsh; common; June Ambrosia artemisiifolia L. Ragweed. Dry to wet infrequent; August-September. September. prairie; abundant; August-September. Liatris aspera Michx. Rough blazing-star. Dry Ambrosia psilostachya DC. Western ragweed. Dry Setaria viridis (L.) Beauv. Green foxtail. Dry prairie; frequent; August-October. prairie; infrequent; July-October. Liatris punctata Hook. Dotted b'lazing-star. Dry prairie to marsh; frequent; June-September. Ambrosia trifida L. Giant ragweed. Disturbed Sorghastrum nutans (L.) Nash. Indian grass. Dry to prairie; common; August-October. prairie; infrequent; July-October. Machaeranthema spin11/osis Greene. Goldenweed. mesic prairie; abundant; August-September. Antennaria neglecta Greene. Pussytoes. Dry to Spartina pectinata Link. Slough grass. Wet prairie Dry prairie; rare; July-September. mesic prairie; common; April-July. Prenanthes aspera Michx. Rattlesnake root. Dry to marsh; common; July-August. Arrtium minus Bernh. Burdock. Disturbed prai Sporobolus asper (Michx.) Kunth. Dropseed. Dry prairie; infrequent; August-September. rie; rare; July-October. Ratibida pinnata (Vent.) Barnh. Gray-headed to mesic prairie; frequent; August-October. Artemisia caudata Michx. Wormwood. Dry Sporobolus heterolepis A. Gray. Prairie dropseed. coneflower. Dry to mesic prairie; common; prairie; infrequent; August-September. June-August. Dry prairie; common; July-September. Artemisia dracunculus L. Linear leaved wormwood. Sporobolus vaginiflorus (Torr.) Wood. Dropseed. Senecio plattensis Nutt. Ragwort. Dry prairie; in Dry prairie; common; July-September. frequent; May-July. Dry prairie; common; August-September. Artemisia ludoviciana Nutt. Mugwort, White Stipa spartea Trin. Porcupine grass. Dry to mesic Silphium laciniatum L. Compass plant. (Gerhardt sage. Mesic prairie; common; July-October. 1940). prairie; common; May-June. Aster ericoides L. Heath aster. Dry to mesic prairie; Zea mays L. Corn. Cowpaths; rare. Silphium perfoliatum L. Cup plant. (Gerhardt common; August-October. 1940). Potamogetonaceae (Pondweed Family) Aster laevis L. Smooth aster. Dry to mesic prairie; Solidago canadensis L. var. silvocanescens Rydb. Tall Potamogeton foliosus Raf. Pondweed. Abundant in goldenrod. Mesic prairie; common; August shallow marsh; June. frequent; August-October. Aster lanceolatus Willd. Panicled aster. Wet prai September. Potamogeton pusillus L. Pondweed. Abundant in Solidago canadensis L. Canada goldenrod. Mesic shallow marsh; June. rie; abundant; August-October. Aster oblongifo/ius Nutt. Aromatic aster. Dry prai prairie; infrequent; July-September. Potamogeton zosteriformis Fern. Pondweed. Fre Solie/ago gigantea Ait. Large goldenrod. Mesic to quent in shallow marsh. rie; common; August-October. Aster puniceus L. Purple stemmed aster. Wet wet prairie; common; August-September. Sparganiaceae (Bur-reed Family) prairie; rare; August-November. Solidago missouriensis Nurt. Missouri goldenrod. Sparganium eurycarpum Engelm. Bur-reed. Com Aster sericeus Vent. Silky aster. Dry prairie; com Dry to mesic prairie; common; July mon in marsh; n marsh; June-July. mon; August-September. September. Typhaceae (Cat-tail Family) Bidens cernua L. Stick-tight. Wet prairie and Solidago nemoralis Ait. Gray goldenrod. Dry Typha latifolia L. Cattail. (Gerhardt 1940). marsh; common; August-October. prairie; common; August-September. Solidago ptarmicoides (Ness.) Boivin. Sneezewort Subclass Dicotyledoneae Bidens frondosa L. Beggar-ticks. Wet prairie; in frequent; June-October. aster. Dry prairie; frequent; July-September. Amaranthaceae (Amaranth Family) Bidens vulgata Greene. Hairy beggar-ticks. Wet Solidago rigida L. Hard-leaved goldenrod. Dry to Amaranthus graecizans L. Tumbleweed. Disturbed prairie and marsh; common; August-October. mesic prairie; common; July-October. dry prairie; infrequent; June-September. Boltonia asteroides (L.) I:Her. Boltonia. Marsh; 1araxacum o.fficinale Weber. Common dandelion. Amaranthus retrof/exus L. Green amaranth. Dis common; July-October. Dry to wet prairie; common; March-Decem turbed prairie; common; August-October. Brickellia eupatorioides (L.) Shinners. False-boneset. ber. Amaranthus tamariscinus Nutt. Pigweed. Disturb Mesic prairie; infrequent; August-October. ed prairie; infrequent; July-September. Carduus nutans L. Nodding thistle. Mesic prairie; Tragopogon dubius Scop. Goat's beard. Dry to Apiaceae (Parsley Family) infrequent; June-October. mesic prairie; infrequent; May-July. Cicuta maculata L. Water hemlock. Wet prairie; Cirsium altissimum (L.) Spreng. Tall thistle. Mesic Tragopogon pratensis L. Goat's beard. (Gerhardt rare; June-August. prairie; infrequent; July-October. 1940). Sium suave Walt. Water parsnip. Marsh; com Cirsium arvense (L.) Scop. Canada thistle. Mesic Vernonia fasciculata Michx. Ironweed. Wee prai mon; July-September. prairie; infrequent; July-August. rie; infrequent; July-September. Zizia aurea (L.) W. Koch. Golden alexander. Cirsium/lodmanii (Rydb.) Arthur. Thistle. Mesic Xanthium strumarium L. Cocklebur. Disturbed Mesic to iret prairie; rare; May-June. prairie; common; June-September. prairie; infrequent; August-September. 106 JOUR. IOWA ACAD. SCI. 98(1991)

Boraginaceae (Borage Family) Astragalus crassicarpus Nutt. Ground-plum. Dry Teucrium canadense L. Germander. Marsh; fre Lappula echinata Gilib. Stickseed. Dry to mesic prairie; common; April-May. quent; June-August. prairie; common; May-September. Dalea candida Willd. White prairie clover. Dry to Lentibulariaceae (Bladderwort Family) Lithospermum canescem (Michx.) Lehm. Hoary puc mesic prairie; frequent; June-July. Utricularia vulgaris L. Bladderwort. Abundant in coon. Mesic prairie; common; April-May. Dalea purpurea Vent. Purple prairie clover. Dry to shallow pond; June-August. Lithospermum incisum Lehm. Narrow-leaved puc mesic prairie; abundant; June-July. coon. Dry to mesic prairie; common; April Desmodium canadense (L.) DC. Showy tick-trefoil. Linaceae (Flax Family) May. Mesic prairie; frequent; July-August. Linum sulcatum Riddell. Wild flax. Dry to mesic prairie; common; June-July. Onosmodium mo/le Michx. var. occidentale (Mack.) Lathyrus palustris L. Vetchling. Mesic to wet I.M. Johnston. False gromwell. Mesic prai prairie; frequent; June-September. Nyctaginaceae (Four o'clock Family) rie; common; June-July. Lathyrus venosus Muhl. Vetchling. Mesic prairie; Mirabilis hirsuta Pursh. MacM. Four-o'clock. Dry Brassicaceae (Mustard Family) infrequent; June-July. prairie; frequent; May-August. Mirabilis nyctaginea (Michx.) MacM. Four-o'clock. Arabis hirsuta (L.) Scop. Rock cress. Dry to mesic Lespedeza capitata Michx. Round-headed bush prairie; frequent; May-June. clover. Mesic prairie; frequent; July-Septem Dry prairie; rare; May-August. Berteroa incana (L.) DC. Hoary alyssum. Dry to ber. Onagraceae (Evening-primrose Family) mesic prairie; infrequent; June-September. Lespedeza leptostachya Engelm. Prairie bush clover. Calylophus serrulatus (Nutt.) Raven. Toothed Capsella bursa-pastoris (L.) Medic. Shepards's purse. Dry to mesic prairie; infrequent;July-Septem leaved primrose. Dry to mesic prairie; com Dry to mesic prairie; rare; April-September. ber. mon; June-July. Descurainia sophia (L.) Webb. Tansy mustard. Medicago lupulina L. Black medick. Dry to mesic Epilobium coloratum Biehler. Purple-leaved wil Disturbed prairie; infrequent; May-July. prairie; common; March-November. low-herb. Marsh; infrequent; July-October. Draba reptans(lam.) Fern. Carolina whitlow-grass. Medicago sativa L. Alfalfa. Dry to mesic prairie; Oenothera biennis L. var. canescens T & G. Evening Dry prairie; common; April-May. infrequent; May-October. primrose. Dry to mesic prairie; common; Lepidium densiflorum Schrader. Peppergrass. Dry to Melilotus alba Medic. White sweet clover. Mesic June-September. mesic prairie; common; May-June. prairie; infrequent; May-October. Oxalidaceae (Wood-sorrel Family) Rorippa islandica (Oeder) Borbas. Yellow cress. Melilotus officinalis (L.) Pall. Yellow sweet clover. Oxalis dil/enii Jacq. Wood-sorrel. (Gerhardt Marsh; common; May-September. Mesic prairie; infrequent; June-August. 1940). Sisymbrium officinale (L.) Scop. Hedge mustard. Oxytropis lambertii Pursh. Locoweed. Dry, sandy Oxalis stricta L. Yellow wood-sorrel. Dry to wet Dry to mesic prairie; frequent; May-October. prairie; common; May-June. prairie; abundant; May-October. Campanulaceae (Harebell Family) Psoralea argophylla Pursh. Silvery scurf pea. Mesic Oxalis violacea L. Violet wood-sorrel. Dry to mesic Lobelia spicata Lam. Pale-spike lobelia. Dry to prairie; frequent; June-August. prairie; frequent; April-June. mesic prairie; common; July-September. Psoralea esculenta Pursh. Breadroot. Dry prairie; frequent; May-July. Plantaginaceae (Plantain Family) Cannabinaceae (Hemp Family) Trifolium campestre Schreb. Low hop clover. Dry to Plantago major L. Common plantain. Mesic Cannabis sativa L. Hemp. Dry to mesic prairie; wet prairie; common; May-September. prairie; common; June-October. infrequent; July-August. Trifolium pratense L. Red clover. Dry to wet prai Plantago rugellii Dene. Pale plantain. Mesic Caprifoliaceae (Honeysuckle Family)' rie; infrequent; May-September. prairie; common; June-October. Symphoricarpos occidentalis Hook. Wolfberry. Mesic Trifolium repem L. White clover. Dry to wet prai Polemoniaceae (Phlox Family) prairie; infrequent; June-August. rie; common; May-September. Phlox pilosa L. Prairie phlox. Mesic prairie; com Caryophyllaceae (Pink Family) Vicia americana Muhl. Vetch. Mesic to wet mon; April-June. prairie; frequent; May-July. Silene antirrhina L. Sleepy catchfly. Dry to mesic Polygalaceae (Milkwort Family) prairie; common; May-July. Gentianaceae (Gentian Family) Polygala verticillata L. Whorled milkwort. Dry to Certophyllaceae (Hornwort Family) Gentiana puberulenta J. Pringle. Prairie gentian. mesic prairie; infrequent; July-October. Ceratophyllum demersum L. Coontail. Abundant in Dry to mesic prairie; frequent; August-Octo ber. Polygonaceae (Smartweed Family) shallow pond. Polygonum aviculare L. Prostrate knotweed. Dry Chenopodiaceae (Goosefoot Family) Hypericaceae (St. John's-wort Family) prairie to marsh; common; June-September. Chenopodium album L. Lamb's quarters. Dry to wet Hypericummajus(Gray)Britt. St.John's-wort. Wet Polygonum coccineum Muhl. Water smartweed. prairie; frequent; June-September. prairie and marsh; common; July-September. (Van der Valk and Davis 1976). Kochia scoparia (L.) Schrader. Summer cypress. Dry Lamiaceae (Mint Family) Polygonum convolvulus L. Black bindweed. Dry to to wet disturbed prairie; infrequent; July Hedermza hispidum Pursh. Mock pennyroyal. Dry mesic prairie; infrequent; June-September. September. to mesic prairie; common; May-August. Polygonum erectum L. Erect knotweed. Dry to Sa/sofa kali L. Common saltwort. Dry prairie; Lycopus americanus Muhl. Cut-leaved water-hore mesic prairie; frequent; June-September. infrequent. hound. Wet prairie and marsh; common; PolygonumhydropiperL. Commonsmartweed. Wet Convolvulaceae (Morning Glory Family) July-September. prairie to marsh; abundant; July-August. Cuscuta glomerata Choisy. Dodder. (Gerhardt Lycopus asper Greene. Bugleweed. Wet prairie and Polygonum lapathifolium L. Pale smartweed. Wet 1940). marsh; frequent; July-September. prairie and marsh; infrequent; July-Septem Mentha arvensis L. Wild mint. Mesic to wet ber. Euphorbiaceae (Spurge Family) prairie and marsh; common; July-September. Polygonum natans Eat. Water smartweed. (Ger Euphorbia dentata Michx. Toothed spurge. Dry to Monarda fistulosa L. Wild bergamot. Mesic hardt 1940). mesic prairie; infrequent; June-September. prairie; common; June-September. Polygonum pemylvanicum L. Pennsylvania smart Euphorbia glyptosperma Engelm. Spurge. Dry to Nepeta cataria L. Catnip. Mesic prairie; rare;July weed. Dry to wet prairie and marsh;· frequent; mesic prairie; abundant; June-September. October. July-September. L. Euphorbia maculata Milk-purslane. Dry to mesic Pycnanthemum virginianum (L.) Durand & Jackson. Polygonum ramosissimum Michx. Bushy knotweed. prairie; infrequent; June-September. Mountain mint. Mesic prairie; infrequent; Dry to wet prairie; infrequent; August-Sept Fabaceae (Bean Family) July-September. ember. Amorpha canescem Pursh. Leadplant. Dry to mesic Scutellaria lateriflora L. Mad-dog skullcap. Marsh; Rumex altissima Wood. Pale dock. Mesic; infre prairie; common; June-August. common; July-September. quent; May-July. Amphicarpabracteata(L.)Fern. Hog-peanut. Moist Scutellaria parvula Michx. Smaller skullcap. Dry Rumex crispus L. Sour dock. Mesic to wet prairie; prairie; frequent; August-September. prairie; infrequent; May-July. frequent; June-July. Astragalus canadensis L. Milk-vetch. Dry to mesic Stachys palustris L. Woundwort. Marsh; frequent; Rumex orbiculatus Gray. Great water dock. Marsh; prairie; frequent; June-August. June-August. rare; July-August. VASCULAR FLORA OF AREND'S KETTLE 107

Portulacaceae (Purslane Family) Geum triflorum Pursh. Prairie avens. Dry prairie; Castilleja sessiliflora Pursh. Downy painted cup. Portulaca oleracea L. Purslane. Dry disturbed rare; May-June. Dry prairie; common; May-July. prairie; rare; June-October. Potentilla argentea L. Silvery cinquefoil. Dry prai Mimulus ringens L. Square stemmed monkey flow Primulaceae (Primrose Family) rie; frequent; June-September. er. Marsh; frequent; June-September. Androsace occidentalis Pursh. Androsace. Dry, san Potentilla arguta Pursh. Tall cinquefoil. Dry to Scrophularia lanceolata Pursch. Figwort. Mesic dy prairie; rare (locally abundant); April. mesic prairie; common; June-August. prairie; frequent; May-July. Lysimachia hybrida Micm. Hybrid lysimachia. Potentilla norvegica L. Rough cinquefoil. Dry to Veronicastrum virginicum (L.) Farw. Culver's root. Marsh; common; June-July. wet prairie; frequent; June-October. Mesic prairie; frequent; June-August. Lysimachia thyrsiflora L. Tufted loosestrife. Marsh; Potentilla rivalis Nutt. Cinquefoil. Wet prairie Solanaceae (Nightshade Family) frequent; May-June. and marsh; frequent; June-August. Physalis heterophylla Nees. Ground cherry. Dry to Prunus _americana Marsh. American plum. Mesic Ranunculaceae (Crowfoot Family) mesic prairie; common; June-September. prame; rare. Anenome canadensis L. Canada anenome. Dry to Physalis pruinosa L. Ground cherry. (Gerhardt Rosa suffulta Greene. Prairie rose. Dry to mesic wet prairie; common; May-August. 1940). prairie; frequent; June-July. Anenome cylindrica Gray. Thimbleweed. Dry to Physalis virginiana P. Mill. Virginia ground cher mesic prairie; common; June-August. Rubiaceae (Madder Family) ry. Dry to mesic prairie; common; June Anenome patens L. Pasque-flower. Dry to mesic Galium boreale L. Northern bedstraw. Dry to August. prairie; common; March-April. mesic prairie; common; June-July. Solanum americanum P. Mill. Common night Delphinium virescens Nutt. Larkspur. Dry to mesic Galium obtusum Bige!. Bedstraw. Wet prairie and shade. Dry to mesic prairie; infrequent; May prairie; frequent; June-July. marsh; common; May-July. September. Ranunculus pennsylvanicus L. f. Bristly crowfoot. Salicaceae (Willow Family) Ulmaceae (Elm Family) Wet prairie and marsh; common; July-Au Populus deltoides Bartram. Cottonwood. Common Ulmus pumila L. Siberian elm. Dry to mestc gust. invader of disturbed wet prairie and marsh. prairie; frequent invader. Ranunculus rhomboideus Goldie. Prairie buttercup. Salix amygdaloides Anders. Peach leaved willow. Urticaceae (Nettle Family) Dry to mesic prairie; frequent; April-May. Common invader of disturbed wet prairie and Parietaria pennsylvanica Muhl. Pellitory. Mesic Fisch. & Ave-Lall. Purple Thalictrum dasycarpum marsh. prairie; infrequent; June-September. meadow rue. Mesic prairie infrequent; June Santalaceae (Sandal-wood Family) July. Verbenaceae (Vervain Family) Comandra umbellata (1.) Nutt. Bastard toad-flax. DC. Meadow rue. (Gerhardt Verbena hastata L. Blue vervain. Wet prairie and Thalictrum revolutum Dry to mesic prairie; common; May-July. 1940). marsh; frequent; June-October. Saxifragaceae (Saxifrage Family) Verbena stricta Vent. Hoary vervain. Dry to mesic Rhamnaceae (Buckthorn Family) Heuchera richardsonii Rr. Prairie alumroot. Dry to prairie; abundant; June-September. Ceanothus americanus L. New Jersey tea. Mesic mesic prairie; common; May-July. prairie; infrequent; June-July. Violaceae (Violet Family) Penthorum sed