KEY TO THE VASCULAR PLANT SPECIES, NATIVE AND NATURALIZED, OF THE SOUTHEASTERN WISCONSIN REGION Compiled by Dr. Lawrence Leitner and Ms. Kristi Sherfinski February 2012 INTRODUCTION This key covers the area comprised by the following seven counties—Milwaukee, Racine, Kenosha, Ozaukee, Washington, Waukesha, and Walworth. The greater Milwaukee area, the largest metropolitan area in Wisconsin, occurs within this area. Despite this fact, the flora of the southeastern Wisconsin is quite diverse. The Tension Zone runs northwest to southeast through the area, crossing through Washington, Ozaukee, Milwaukee, and Racine counties. The Tension Zone is a climactic zone which divides Wisconsin into a northern hardwoods- conifer forest floristic province and a southern prairie-oak forest floristic province (SEWRPC Planning Report No. 42, 1997). Because of this Tension Zone, the flora of the Region represents a microcosm of the entire state. The Region contains every plant community listed in the “Vegetation of Wisconsin” (Curtis, 1959), except for the boreal forest and the sand barren community types. In addition, the Kettle Moraine State Forest is located along the western edge of the Region. This area contains many examples of glacial features formed as a result of the last glaciation event—the Wisconsin Stage—that occurred about 11,000 years ago (SEWRPC Planning Report No. 42, 1997). This is a draft document that was compiled by Dr. Lawrence Leitner and Ms. Kristi Sherfinski while working for the Southeastern Wisconsin Regional Planning Commission (SEWRPC). It encompasses all vascular species that are native or that have become naturalized in the southeastern Wisconsin region, as defined above, according to their records at the time this key was written in 2012. This document is currently in draft form and is not an official publication of SEWRPC and should not be referenced as such. It has been tested by the authors but we wish to have it further tested by users before removing its draft status. Please feel free to send your comments or edits to Ms. Sherfinski at [email protected]. None of this work would have been possible without the work of our predecessors, and the support of SEWRPC. These works are referenced at the end of this document. SE WI Plant Key, p. 2 SE WI Plant Key, p. 3 KEY TO VASCULAR PLANT GROUPS 1. Plants without flowers or seeds, reproducing by spores borne in sporangia on leaves or specialized structures ............................................. PTERIDOPHYTES—FERNS AND FERN-ALLIES 1. Plants normally reproducing by seeds containing an embryo, via cones or flowers ................ 2 2. True flowers not produced; seeds borne on surface of a scale or partially embedded in a fleshy disk; never enclosed in a fruit; plants without styles, stigmas, or perianths; all woody—trees and shrubs; leaves narrow, needle-like or scale-like, mostly evergreen; seeds exposed, not borne in a closed structure ........................................................ GYMNOSPERMS 2. Plants typically bearing flowers at the proper season and reproducing by stamens and pistils, the latter producing seeds; perianth definitely present; true flowers with stamens and pistils; ovules enclosed in ovary of flower, which at maturity become seeds within fruit .. .............................................................................................................................ANGIOSPERMS SE WI Plant Key, p. 4 KEY TO PTERIDOPHYTE FAMILIES: FERNS AND FERN-ALLIES 1. Leaves narrow, sessile, 1-veined, simple, linear or oval; sporangia borne in cones ................. 2 2. Leaves small, scale-like, whorled, united to form toothed sheaths at conspicuous nodes (joints) on grooved, usually hollow stems .......................................................... EQUISETACEAE 2. Stems leafy, solid, not conspicuously jointed or grooved; leaves spirally arranged or in four rows, not whorled ..................................................................................................................... 3 3. Cones terminal, more-or-less 4-angled; sterile leaves with inconspicuous ligule present at base; plants small, creeping, moss-like ...................................................... SELAGINELLACEAE 3. Cones terete, or sporangia borne in axils of vegetative leaves and not forming a cone; sterile leaves without ligules at base; plants trailing, but not moss-like ................................. .......................................................................................................................... LYCOPODIACEAE 1. Leaves broad, petiolate, often compound, with several branching veins; sporangia never in cones (Ferns) ................................................................................................................................ 4 4. Sporangia borne in a stalked terminal spike or loose panicle .................. OPHIOGLOSSACEAE 4. Sporangia borne in clusters (sori) on backs of ordinary or modified foliar leaves, or in pod- like divisions of modified leaves ............................................................................................... 5 5. Sporangia densely crowded, short-stalked, globose ................................... OSMUNDACEAE 5. Sporangia in sori on backs or margins of leaves ......................................... POLYPODIACEAE KEY TO PTERIDOPHYTE GENERA SELAGINELLACEAE ............................................................................................................ Selaginella EQUISETACEAE ..................................................................................................................Equisetum LYCOPODIACEAE ............................................................................................................ Lycopodium OSMUNDACEAE ................................................................................................................. Osmunda SE WI Plant Key, p. 5 OPHIOGLOSSACEAE 1. Sterile leaf simple, entire, undivided, rather unfern-like; veins netted; fertile portion an undivided spike or spikes; sporangia sessile, in two rows........................ Ophioglossum pusillum 1. Sterile leaves lobed, compound, and/or much dissected; veins merely forked; fertile portion much branched; the numerous sporangia short-stalked ............................................ Botrychium POLYPODIACEAE 1. Sori marginal on leaf edges ........................................................................................................ 2 2. Frond blades kidney-shaped, dichotomously branched at base, each frond with 5-9 pinnately divided pinnae on one side .......................................................... Adiantum pedatum 2. Frond blades not kidney-shaped or dichotomously branched at base .................................. 3 3. Fertile and sterile leaves very dissimilar .............................................................................. 4 4. Sterile blades simple, pinnatifid to 1-pinnate at base ............................ Onoclea sensibilis 4. Sterile blades 1-pinnate-pinnatifid ............................................ Matteuccia struthiopteris 3. Sterile and fertile fronds similar .......................................................................................... 5 5. Fronds robust, about 1 m high ............................................................ Pteridium aquilinum 5. Fronds delicate, less than 0.25 m long ............................................................................. 6 6. Leafstalks wiry, dark-colored; pinnules jointed at base ......................... Pellaea glabella 6. Leafstalks weak, mostly greenish; pinnules not jointed at base ...................................... ........................................................................................................ Cryptogramma stelleri 1. Sori not marginal ........................................................................................................................ 7 7. Fronds simple, entire, heart-shaped at base, glabrous; apex often rooting ............................. ............................................................................................................ Camptosorus rhizophyllus 7. Fronds never simple and entire; apex never rooting ............................................................. 8 SE WI Plant Key, p. 6 8. Sori linear, oblong, or crescent-shaped ............................................................................... 9 9. Fronds leathery, evergreen, blades linear-oblong, less than 8 cm wide; rachis wiry, glossy, darkish throughout .............................................................. Asplenium platyneuron 9. Fronds thin, not leathery, deciduous; blades ovate, more than 8 cm wide; rachis greenish ............................................................................................................................. 10 10. Adaxial grooves of costae shallow, not decurrent into rachis groove; stems moderately long creeping; blades 1-pinnate-pinnatifid ................ Deparia acrostichoides 10. Adaxial grooves of costae deep, decurrent into rachis groove; stems short-creeping to erect; blades 1-pinnate to 2-pinnate-pinnatifid ..............................................Athyrium 8. Sori round or nearly so; neither linear nor crescent-shaped ............................................. 11 11. Fronds evergreen, leathery, pinnate; pinnae spinulose-serrate, asymmetrically 1- lobed at base with lobes aimed distally; indusia absent ........... Polystichum acrostichoides