Many species of orchids are found in Minnesota prairies, but only three are prairie specialists: western prairie fringed orchid, Great Plains ladies’ tresses, and small white lady’s slipper. They all occur in lime-rich sediments deposited by glaciers and in clay-rich soils of glacial lake beds.
Small white lady’s slipper (Cypripedium candidum) is widely scattered but uncommon across the Great Lakes states to the Dakotas and adjacent Canadian provinces. Minnesota is the core area of the species and may have more individual plants than all other states and provinces combined. It is found in relatively undisturbed, high-quality prairies in the western, southern, and metro regions of the state.
Small white lady’s slipper produces small flowers that are easily overlooked. The best time to see it in bloom is … right now, the last week of May in southern Minnesota and the first or second week of June in the north.
There are six Asian bush honeysuckles that have been introduced into North America and are now naturalized here. Three of these, Bell’s, Morrow’s, and Tartarian honeysuckle, are found in Minnesota. A fourth, Amur honeysuckle, has spread to Wisconsin and Iowa and will probably reach Minnesota soon.
In the past, Bell’s honeysuckle (Lonicera x bella) was widely planted in eastern and mid-western North America, including Minnesota, to control erosion and as an ornamental. It has since spread aggressively to a broad range of natural and semi-natural habitats. It leafs out early in the spring, grows vigorously and large, crowds other plants, shades the ground, and uses available soil moisture and nutrients. It may also release a chemical into the soil that further inhibits the growth of other species.
Bell’s honeysuckle is a horticultural cultivated fertile hybrid of Morrow’s honeysuckle and Tartarian honeysuckle. As a hybrid, it shares characteristics of both of its parents, and is difficult to distinguish from them. Bell’s honeysuckle is identified by its leaves, which are sparsely to moderately hairy on the underside, at least along the main veins; and by the minute bractlets at the base of each flower, which are at least half as long as the ovary which they subtend.
There are about 75 species of spurred gentian (genus Helenia) worldwide. Only two occur in North America north of Mexico. Only one, American spurred gentian (Halenia deflexa ssp. deflexa), is found in Minnesota.
American spurred gentian is an often overlooked member of the Gentianaceae (gentian) family. Its flowers are much smaller and less showy than the more common bottle, pleated, and fringed gentians. It blooms in northern Minnesota under partial shade in moist coniferous forests (especially at the edges), cedar swamps, and bogs, and on river banks. It is often encountered on woodland trails that are wide enough to allow some sunlight to filter through.
From July to August American spurred gentian produces clusters of green to yellowish, often purplish-tinged flowers. The flowers have four petals, each of which has a long, downward-pointing spur at the base. There are no similar species in Minnesota.
There are at least 78 species of bladderpod (genus Physaria) recognized in North America. Most of them are restricted to western United States. Only Louisiana bladderpod (Physaria ludoviciana) is found in Minnesota. The natural range of this plant is from Montana and North Dakota, south to New Mexico and Arizona, and north to Manitoba and Saskatchewan. In Minnesota it is found in full sun growing on sandy soil on steep, south-facing, weathered, dolomitic sandstone bluffs. Spring Creek Prairie SNA has one of the largest known populations. Most of the other populations are within the city limits of Redwing.
Louisiana bladderpod is is common in its natural range but is classified as endangered in Minnesota and Illinois, threatened in Wisconsin. The few known populations in Minnesota may have been transplanted by a seed dropped by a bird, or may have survived from a time when the central plains extended into the area long ago.
Louisiana bladderpod is identified by its narrow, unlobed leaves forming a basal rosette; yellow flowers; and inflated, hairy, more or less globe-shaped fruit. There are no similar species in Minnesota.
Marsh skullcap (Scutellaria galericulata) is a common and widespread plant in wetlands across North America. It is found throughout Minnesota in wet meadows, marshes, bogs, fens, swamps, stream banks, pond edges, and roadside ditches. It is often overlooked as its weak stems lean against nearby plants and its blue flowers, though showy, appear sparsely.
There are five skullcap species in Minnesota. Marsh skullcap is distinguished by its leaves which are narrow, no more than ¾″ wide, shallowly round-toothed, very short stalked or stalkless, and pinnately veined with lateral veins that branch and rejoin before reaching the margin; flowers more than ½″ long rising from leaf axils but not at the end of the stem; and its preference for wetlands.
Four-flowered yellow loosestrife (Lysimachia quadriflora) is a slender, non-woody, flowering plant. It is common in moist and wet prairies across eastern North America. In Minnesota it is found throughout the state except for the Arrowhead region.
When not in flower, the foliage of four-flowered yellow loosestrife is easily overlooked among the taller prairie grasses. The stem is slender and the opposite leaves are narrow, up to 3½″ long but no more than ¼″ wide. The flower arrangement often appears as a whorl of four flowers, each one pointing in a different direction and nodding at the end of a slender stalk. In late summer the flowers are replaced by a shiny, globe-shaped, seed capsule with a long sharp spine at the tip. The capsule ripens in the fall.
Four-flowered yellow loosestrife is identified by the narrow leaves, nodding yellow flowers, and globe-shaped fruit capsule. When in flower, it is similar in appearance to fringed loosestrife (Lysimachia ciliata) and whorled loosestrife (Lysimachia quadrifolia). Both of those species have much wider leaves.
Photo by Randy
Kentucky coffee tree (Gymnocladus dioicus) has the largest leaves of any tree in Minnesota. They are 12″ to 36″ long, up to 24″ wide, and twice compound with 40 to 100 leaflets. They are the latest to appear in the spring in Minnesota and one of the first to drop in autumn.
Kentucky coffee tree is uncommon or rare wherever it is found. The large fruit pods of Kentucky coffee tree are probably an adaptation to large mammals of the Pleistocene epoch. Horses, giant sloths, mastodons, and mammoths were present on the North American continent for millions of years. They probably ate the pods and dispersed the seeds in their scat. They disappeared in the Late Pleistocene extinction event, 20,000 to 10,000 years ago, when all large mammals (over 2,200 pounds) in North America went extinct.
Kentucky coffee tree is identified by its large, twice-compound leaves with 40 to 100 leaflets; and the thick, somewhat flattened, 3″ to 6″ long fruit pod.
Celandine (Chelidonium majus) is native to Europe, Asia, and North Africa. It was introduced and cultivated in eastern North America as an ornamental. It occasionally escapes cultivation and is now well established in moist woodlands from Maine to Ohio south to Virginia. It is uncommon in Minnesota.
Celandine is found in full sun to light shade in moderately moist woodlands, thickets, hedge rows, roadsides, railroads, and waste places. It produces small clusters of bright yellow, 4-petaled flowers from May to August. There is a double-flowered form of this plant that produces flowers with 12 to 24 petals each. The sap is bright yellow or yellowish-orange and toxic. It is a skin irritant and has been used medicinally to treat warts.
Celandine is easily identified by its leafy stems with 5- to 9-lobed leaves; bright yellow, 4-petaled flowers; and ascending, slender, hairless seed capsules. There are no similar species in Minnesota.
Fragrant sumac (Rhus aromatica var. aromatica) is common in eastern and central United States from Connecticut to Kansas south to Georgia and Texas. In is uncommon in the upper Midwest. It is native to Minnesota but has been recorded only in Goodhue and Winona Counties. It is sometimes used for stabilizing embankments. The low-growing cultivar Gro-Lo is sold as an ornamental shrub.
Fragrant sumac is found in prairie ravines, open hillsides, woodland edges and openings, and sand dunes. In April and May it produces small clusters or greenish-yellow flowers. In late summer these turn into clusters of hairy, bright red berry-like fruits. Stems and leaves, when crushed, have an odor which has been variously described as citrussy, pleasantly bittersweet, very unpleasant, and malodorous.
Fragrant sumac is easily distinguished by its leaves with only 3 leaflets. Smooth sumac and staghorn sumac both have leaves with 11 to 31 leaflets.
Lance-leaf fog-fruit (Phyla lanceolata) is common in its core range from Ohio to Kansas, much less common in Minnesota. It is found in wet to moist areas along streambanks, margins of ponds and lakes, marshes, and roadside ditches. From June to September it produces numerous small heads of many tiny flowers surrounding a purple cone.
The common name “fog-fruit” comes from an old Scottish word for moss, fog. It refers to the matted, moss-like habit of the plant. Another common name “frog-fruit” originated in what appears to be a typographical error in the 1834 book Botanical Teacher for North America. The error has persisted and is now the most commonly used name for this plant.
The flower heads of lance-leaf fog-fruit are distinctive. There are no similar species in Minnesota.