Spring ladies’ tresses is Missouri’s tallest species of ladies’ tresses orchid (Spiranthes). It flowers earlier than our other species that have their flower clusters appearing as a single, easy-to-discern spiral. The single spiral is a key identifier, as some of our other ladies’ tresses have the single or seemingly double rows of flowers twisted so tightly that the underlying spiral arrangement is hard to discern.
Like other ladies’ tresses orchids, this species appears as a single flowering stem with a dense cluster of stalkless, white, urn-shaped flowers at the tip. In this species, the flowers’ single (not double) spiral arrangement is apparent. Also note that the flower stalk has dense, short hairs. The flowers are relatively large for this genus, with the sepals and lateral (side) petals 6–9.5 mm long. Blooms late June–mid-July (sometimes into September). About 4–6 linear (grasslike), smooth, basal leaves are present at flowering time.
The common name of "spring" or "vernal" ladies’ tresses is misleading, because this species does not start blooming in our state until late June. It and the similar greenvein ladies' tresses do bloom earlier than most of our ladies’ tresses, which flower in late summer into fall. Another species, however, is more deserving of the “spring” name: shining ladies' tresses or yellow-lipped ladies' tresses (S. lucida), which flowers May–June and it is our earliest flowering Spiranthes.
Similar species: Eight Spiranthes species grow in Missouri. Slender and little ladies’ tresses are similar to vernal ladies’ tresses, since they also have flowers in a single spiral, but they both bloom later, in August–October. Another single-spiraling species, greenvein ladies' tresses, blooms earlier, in late May–early June, but it is rare and you are unlikely to see it.
- Greenvein ladies' tresses (S. praecox) blooms in our state in late May–early June. It is a species of conservation concern in Missouri and is known from only one location in Stoddard County, along the edge of a wetland. It was first reported for our state in 2015. It occurs mostly in the Atlantic Coastal Plain and southeastern United States, and its location in southeast Missouri represents a northwestern limit of the overall range. Unlike the similar spring ladies' tresses, the flowers usually have green veins or streaks on the lower lip, and the growing stalk is only sparsely hairy.
- Slender ladies' tresses (S. lacera) flowers August–October. It is scattered nearly statewide except for the far northwestern corner. It lives in dry upland forests, upper slopes of bluffs, dry upland prairies, mostly on acidic substrates; also in old fields and a variety of other disturbed, open situations, especially in dry, cherty or sandy soils. It is a slender, delicate plant with a thin stem. The flowers appear as a single spiral, although sometimes no spiral is discernable. Unlike the closely related little ladies' tresses (S. turberosa), it has a green spot on the lip of each flower and has somewhat longer, sparsely glandular-hairy flower spikes. Of the two, S. lacera is generally taller, more slender, and has a more regular, more graceful spiral of flowers.
- Little ladies' tresses (S. tuberosa) flowers August–October. It is scattered, mostly south of the Missouri River, and it lives in upland forests, bluff tops, mostly on acidic substrates; also in old fields, dry roadsides, often in dry, sterile, cherty or sandy soils; sometimes also in lawns. The flowers appear as a single spiral along the flowering stem. It is similar and closely related to slender ladies' tresses (S. lacera), but little ladies' tresses has the lower lip all white, and the center axis of the flower spike is glabrous (smooth; hairless), not glandular-hairy. S. tuberosa and S. lacera are sometimes found growing near each other.
- Nodding ladies' tresses or common ladies' tresses (S. cernua) flowers August–November. It is one of the most common and widespread of Missouri’s ladies’ slipper orchids, most common south of the Missouri River. In occurs in glades, upland prairies, and old fields on acidic substrates; also in acidic soils in moist forests, thickets, and open stream valleys. Flowers appear as though they are 2 or more intertwined spirals along the flowering stems — if spirals are discernible at all. Growing up to 20 inches tall, it is most similar to Great Plains ladies’ tresses, which used to be considered the same species.
- Great Plains ladies' tresses (S. magnicamporum) flowers September–November. It is scattered in the Ozark and Ozark Border divisions and lives in dolomite glades, and, less commonly, in openings of dry upland forests, fens, and limestone glades. Formerly considered a variety of S. cernua and is difficult to distinguish from it. Part of the difficulty is that S. cernua is itself quite varied. But S. magnicamporum has a strong sweet scent like freshly cut hay; its flowers are broadly urn-shaped, curving mostly near the base, with the lip still diverging from the upper sepal and lateral petals about a third of the way from the tip; however, the lateral sepals are spreading, the tops arching upward and angled away from the rest of the perianth (petals). The basal leaves have withered away by flowering time.
- Shining ladies' tresses or yellow-lipped ladies' tresses (S. lucida) flowers in May–June and is our earliest flowering Spiranthes. (The others mostly bloom in late summer and fall.) It is restricted to fens and seeps in the Ozark and Ozark Border regions. It has a bright yellow area on the lip of the flower and has broad, shiny leaves. The flowers appears as though in 2 or more ranks along the stems.
- Oval ladies' tresses (S. ovalis var. erostellata) flowers September–October. It is uncommon and widely scattered in Missouri. It lives in wet to moist bottomland forests, moist upland forests, and less commonly in shaded portions in old fields. Grows to 16 inches high, and the 2 or 3 hairless, dark green, grasslike basal leaves are present at flowering time; the broadest portion of the leaf blade is at the outer tip, not at the base. Flowers are crowded in 2 or more ranks or intertwined spirals; the flower spike is covered with downy hairs.
Height: 20 to 40 inches (occasionally blooms at only 8 inches). Our tallest ladies’ slipper.
Widely scattered, mostly south of the Missouri River.
Habitat and Conservation
Occurs in rich/moist and dry upland prairies; also in prairielike embankments along roads and railroads, and less commonly in prairie fens.
As with many other orchids, the number of flowering plants varies greatly from year to year, with abundant flowering stems at some sites followed by years when the plants are not noticeable.
Orchids have complex relationships with symbiotic fungi in the soil and rarely survive attempts to transplant them. Please leave them in their natural habitats.
Status
Native perennial wildflower.
Human Connections
The common name of "ladies' tresses" apparently arose because the spiral arrangement of the flowers resembles long, braided or curled hair. One of the reasons many common names of plants have endured for so long is their poetic or colorful way of describing some aspect of the plant; they are easy to remember!
Apparently, this species was named for springtime (vernalis) from populations in Florida and the southeastern United States, where they bloom earlier in the year.
Botanists debate the classification of orchids, and genetic testing has helped define the boundaries between species and genera.
Morphology (the form and shape of various plant parts) can be deceiving in this group. For example, the species of Spiranthes in Missouri all have the flowers fundamentally arranged in a single spiral. However, in some of them, the spiral is so tight, and each loop of flowers around the axis occupies so little vertical space, that the overall appearance presents the illusion of two or more vertical ranks or intertwined spirals. Sometimes, in such plants, the spiral nature of the flowers is not discernable at all.
Ecosystem Connections
Orchids are famous for their outrageous diversity in flower shapes. Their weird flower parts — lips, columns, saclike pollen masses, sticky pads, and more — are adaptations to entice and enable pollination by various insects. The spiral pattern of ladies' tresses is thought to encourage pollination by bees.
Most of the species in genus Spiranthes are pollinated by various bees, ranging from bumblebees to honeybees and smaller, native bees. The spiral pattern typical of Spiranthes orchids is thought to be an adaptation to bee pollination. Cora Steyermark observed that the flowers open "first at the bottom of the spike. The bee that fertilizes the orchid starts with the older flowers at the bottom and spirals up with the flowers around the spike, like the little brown creeper bird, following the flowers upward to the top, picking up pollen on the way up. Then again, like the brown creeper, the bee flies to the lower flowers of the next orchid plant spreading pollen" as it again spirals upward.
