Cedar Creek Natural History Area

Plants of Cedar Creek

The large Composite Family with ca. 90 species in 35 genera at Cedar Creek contains a fair number of species that are introduced, and these are discussed first.

The first species to flower in the Lab lawn and disturbed places is the introduced and ubiquitous Dandelion (Taraxacum officinale). T. erythrospermum (Red-seeded Dandelion) also present, but undifferentiated. Chamomilla suaveolens (=Matricaria: Pineapple Weed) is found on the Lab lawn. Crepis tectorum (Alien HawksBeard) is an abundant weedy species of fields that arrived in the 1950s or thereabouts. Two other early season field composites are species of Tragopogon (Goat’s Beard). T. dubius is much more common than T. pratensis. Galinsoga quadriradiata is an uncommon garden weed.  Chrysanthemum leucanthemum (Ox-eye Daisy), an introduced ornamental, only occurs at GH. C. lanceolata  is a garden plant that has disappeared. It does not appear to spread on sand plain soils. Hieracium aurantiacum (Orange Hawkweed) is a recent introduction to the Area and rather aggressive.  It occurs in B, BDG, PPF, and E and is spreading.  Sonchus arvensis (Sow Thistle) is a tall, yellow-flowered weed that grows luxuriantly in wet ditches.  Ditches are also where one runs into many of the thistles (Circium spp). C. arvense (Canada Thistle) is abundant while the taller C. vulgare (Bull Thistle) is found sparingly along the shoreline of Fish Lake.  Lactuca serriola (Prickly Lettuce) is occasionally encountered in old fields. Arctium minus (Common Burdock) is an uncommon bushy weed of woodland (STS).  Tanacetum vulgare (Common Tansey), a late-flowering weedy species of roadsides, has not been seen recently.

The earliest native composites to flower are species of Antennaria (Pussytoes).  These incredibly messy species are dealt with  here as complexes.  While being dioecious, apomixis (setting seed without fertilization) is commonplace, resulting in 'individualistic' clones. A. neglecta complex (incl. varieties canadensis, neodioica) is the most common species in old fields A. plantaginifolia (a broad-leaved complex with three veins) is fairly common in woodland. A. parvifolia is a 'good' but uncommon species, frosty white with little leaves,  found in a few fields (B and BGN).

Erigeron strigosus (Daisy Flea Bane) is fairly common in old fields, while E. philadelphicus (Philadelphia Fleabane) with pink flowers is an uncommon species sometimes found along the shoreline of Fish Lake.  E. annuus is an uncommon species of gardens and rich disturbed soil.  A common but rather weedy species of old fields is the white-flowered Achillea millefolium (Yarrow).  It is often found in association with Rudbeckia hirta (Black-eyed Susan).   Of the native species of Circium, C. discolor (Field Thistle) is a tall robust species found in a few fields (BGN…) and C. muticum (Swamp Thistle) occurs in lowland woods and marshes (Crone’s Knoll, RRF).  Three native weedy species of Lactuca (Wild Lettuce) that occur here are L. biennis, L. canadensis, and L. pulchella.

 An early flowering species of wet depressions in the burn area south of Fish Lake is Krigia biflora (Two-flowered Cynthia).  Two genera of early to mid summer yellow-headed composites are Hieracium (Hawkweeds) with four native species and Senecio (Ragworts) with three.  H. longipilum is a tall hairy species that is fairly common in xeric fields.  H. scabriusculum is abundant along the South Bank of Fish Lake.  H. kalmii and H. scabrum are found in open woods along NSLR.  The most common Senecio  is S. pauperculus.  It occurs at the rim of several wet depressions.  Less common are S. aureus (marsh near creek) and S. plattensis (collected 1959). Coreopsis palmata  (Bird-foot Coreopsis) is a common yellow-flowered forb of savanna.  Heterotheca villosa (=Chrysopsis: Golden Prairie Aster) is fairly common in xeric old fields.  Anaphalis margaritacea (Pearly Everlasting) occurs along the edge of Duck Dep across from the gate to D.

 Abundant weedy species of disturbed areas flowering later in the summer include:  Conyza canadensis (Horseweed) and Ambrosia artemisiifolia (Annual Ragweed).  A. coronopifolia (Western Ragweed) is a common perennial forb of brome and other old fields. A. trifida (Giant Ragweed) is an uncommon species once found near the Nature Trail on Fish Lake.  Two species of Artemisia  include the weedy A. campestris (Tall Wormwood) and A. ludoviciana (Gray Sage).  Both are common plants of old fields and savannas.  Erechtites hieracifolia is a weedy species of disked woodland trails and dried up wetlands. Iva xanthifolia (Marsh Elder) is a weedy plant of disturbed areas (Nature Trail Parking Lot).  Lygodesmia juncea (Skeleton-weed) is a rare species of sand prairie, but found here in an odd location--a sandy ditch bank.

 Three large genera of mid to late summer flowering species are Helianthus (Sunflowers), Solidago (Goldenrods), and Aster (Asters).

 Of the five species of Helianthus, H. rigidus (=laetiflorus: Red Stem Sunflower) is common in xeric old fields and savanna. H. petiolaris (Prairie Sunflower) occurs sparingly along sandy roadsides. H. giganteus (Giant Sunflower) is common at marsh edges. H. hirsutus (Woodland Sunflower) is found here and there in woodland. H. annuus (Common Sunflower) is a crop plant found in gardens and occasionally at bird feeders.

 Nine species (+varieties) of Solidago are found on the Area.  Common field species are the clonal S. missouriensis, S. canadensis, and S. gigantea.  The latter two also occur in ditches and wetter sites.  S. nemoralis (Gray Goldenrod) is the most common species of xeric fields and savanna. S. speciosa (Showy Goldenrod) is a fairly uncommon species of savanna and a few old fields (CNW, HAS, RCB).  It is peculiar in that there are early and late flowering forms.  S. hispida (Hairy Goldenrod) is uncommon in woods openings, along NSLR, and Lab entry. S. rigida (Rigid Goldenrod) is a rather weedy species found in several old fields. S. uliginosa (Bog Goldenrod) occurs in Reiling Fen and peaty wetlands. S. flexicaulis (Zig-zag Goldenrod) is found on Crone’s Knoll. Euthamia graminifolia (Grass-leaved Goldenrod) is a common plant of savanna and wetland edges. E. gymnospermoides, a diminutive form, occurs in a few savanna areas.

Thirteen species of Aster are found on the Area.  A. oolentangiensis (=azureus: Sky Blue Aster) is a late-flowering common species of prairie and savanna. A. ericoides (Heath Aster) with tiny white flowers  and tiny leaves is found in swales of several old fields.  A. sericeus (Silky Aster) is a rare species of savanna (last seen along NSLR). A. macrophyllus  and A. saggitifolius are two common heart-leaved species of upland woods.  A third heart-leaved species, A. ciliolatus, is occasionally found at woods edges; a similar species, A. cordifolius, has not yet been collected. Three common species of marshes, ditches and wetlands are  Aster puniceus (Purple Stem Aster), A. umbellatus (Umbel Aster), and A. lanceolatus(=simplex). In peaty wetlands you will find A. borealis (=junciformis).  In wet woods, A. lateriflorus is common and A. ontarionis is uncommon. A. novae-angliae was once planted in a garden and once seen along the creek but does not occur naturally here.

Liatris aspera (Rough Blazing Star) is the only Blazing Star that naturally occurs here.  It is common in prairie and savanna.  This tall forb with late summer flowers bursting in lavendar attracts numerous migratory Monarch butterflies. L. pycnostachya occurs (naturally?) in a few wetlands nearby and may eventually find its way here.  L. cylindracea once popped up on a trail. L. ligulistylis occurs on sandplains further north in Minnesota and L. punctata is as close as the St. Croix Valley---they may also turn up here at some future date.

Three species of Eupatorium are found on the Area.  The white-flowered E. perfoliatum (Boneset) and pink-flowered E. maculatum (Joe-Pye Weed) are two common species of marshes and shorelines.  E. rugosum (Common Snakeroot) is an uncommon species of woods (NSLR, Dead Animal House). Vernonia fasciculata (Ironweed) was last noted in 1980 along the NE shore of Fish Lake.  Two species of Prenanthes (Rattlesnake Root) are P. alba and P. racemosa.  Both are occasionally encountered on wet depression rims in fields and woodland. Gnaphalium obtusifolium (Sweet Everlasting) is a conspicuous pale late-flowering forb of old fields.  After rain, it exudes the smell of molasses.

The genus Bidens (Beggar Ticks) with four species are common marshland and pond edge species of late summer.  B. coronata (Showy Beggartick) is found in the cedar swamp surrounding CBL.  The most common species of marsh edges and drying muck are B. cernua,B. connata and B. frondosa.