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Northern Prairie Wildlife Research Center

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Aquatic and Wetland Vascular Plants of the Northern Great Plains

69. Orchidaceae, the Orchid Family

5. Spiranthes Rich. -- Ladie's-tresses

4. Spiranthes vernalis Engelm. & A. Gray -- Spring ladies'-tresses

Plants 2-7 dm tall, finely pubescent above with whitish or reddish-brown, septate hairs, these eglandular, sharp-pointed; roots coarse, fusiform. Leaves basal or a few cauline, usually some persistent at flowering time, linear to narrowly lanceolate, 5-30 cm long, to 16 mm wide, acuminate, the basal leaves sheathing the stem, the cauline leaves, when present, much reduced and bractlike upward. Spike dense to rather loose with a single twisted spiral of flowers, 3-15 cm long, the bracts ovate to oblong-lanceolate, 7-23 mm long, acuminate, scarious-margined. Flowers yellowish to greenish-white, often fragrant; perianth segments pubescent on the outside; sepals linear-lanceolate, 6-8 mm long, the upper acute to obtuse, the lateral ones free, projected forward, acute; lateral petals connivent with the upper sepal to form a hood, linear to linear-elliptic, 5-9 mm long, obtuse; lip broadly ovate to oblong-ovate, 4.5-8 mm long, widest just below the middle, arcuate-recurved, crenulate-wavy on the margins, strongly papillose on the underside, the basal protuberances prominent, projected backward and uncurved, pubescent. Aug--Sep. Wet meadows, moist prairies, ditches, and floodplains, usually where sandy; uncommon, extreme se SD and e NE; (MA and Que. to SD, s to FL, TX and NM; also Mex. and Guat.).
GIF- Distribution Map

Map key

Previous Section -- Spiranthes romanzoffiana Cham. -- Hooded ladies'-tresses
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