Triosteum perfoliatum (Late Horse Gentian)
|Also known as:||Fever-wort, Wild Coffee|
|Habitat:||part shade, sun; dry woods, thickets, poor rocky soil|
|Bloom season:||May - June|
|Plant height:||2 to 4 feet|
|Wetland Indicator Status:||none|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Clusters of 2 to 6 stalkless, tubular flowers in the leaf axils. Flowers are velvety, purple brown to red, ½ to ¾ inch long. Blossoms open up and angle outward mid-tube, ending in 5 round lobes with a conspicuous light green style protruding from the tube. The yellow stamens remain recessed below the lobes. The 5 sepals are covered in fine downy hairs, long and narrow and may be longer than the flower.
Leaves and stems:
Leaves are opposite, long and broad, 4 to 9 inches long, 2 to 4 inches wide, broadly oval elliptic tapering to a sharp tip, toothless with somewhat wavy edges, the surfaces softly hairy, especially on the underside. The base narrows abruptly, joining the opposite leaf base, usually completely encompassing the stem (perfoliate). Leaf pairs are at right angles to the pair below. The stem is unbranched, covered in short, soft hairs.
Fruits are round to egg shaped, 1/3 to ½ inch long with the 5 long sepals arrayed from the end. The fleshy coat, turning a dull yellow orange when ripe, covers a large hard seed in the center (drupe).
Late Horse Gentian grows in hardwood forest openings and margins along the tension zone between the drier southwestern prairie and the northeastern boreal forest, and is well adapted to both rich mesic soils and poorer gravelly ones. While lore has it that seeds were roasted and used as a coffee substitute, there is little evidence it was widely utilized in this manner and more likely the reputation simply came from the observation that the dried seeds bear a resemblance to coffee beans. A similar species is Early Horse Gentian (Triosteum aurantiacum) which has much the same flower except the green style does not extend out of the tube as far, has leaves that narrow at the base but do not encompass the stem (though this can be difficult to distinguish sometimes), and red-orange fruit. Early also has longer hairs on the stem than Late, but not dramatically so.
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Photos by K. Chayka taken in Hennepin, Washington and Dakota counties. Photos courtesy Peter M. Dziuk taken in Dakota and Hennepin counties.
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