| Author | Engelmann & A. Gray | |
| Distribution | Essentially statewide, but quite spottily distributed in the Mountains and foothills, perhaps truly absent in a few areas in the western part of the state. Occurs throughout the Coastal Plain and the eastern and central Piedmont, though of more infrequent occurrence in the Piedmont than in the Coastal Plain. Frequent on the Outer Banks.
This species has a fairly broad Eastern distribution, occurring as far north as MA and extreme southeastern SD, and then south to the Gulf Coast. It is of spotty occurrence north of the Ohio River, but in some Southern states it has been recorded from most counties.
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| Abundance | Fairly common across most of the Coastal Plain, even in the northern counties, where few others in the genus are numerous. Uncommon to infrequent in the Piedmont, but quite rare toward the foothills. Rare in the Mountains. On the Outer Banks in June, moist unmowed roadsides and lawns can sometimes be whitened by hundreds to thousands of flowering plants. | |
| Habitat | This species occurs in somewhat less wet places than the similar S. praecox, though their habitats do overlap. S. vernalis favors somewhat damp grassy places such as savannas, open flatwoods, powerline clearings, meadows, bogs, and even in drier fields and roadsides. Thus, it has as great a variety of habitats as any Spiranthes species, being found in both wetlands and uplands. | |
| Phenology | Blooms mostly in late spring-early summer in the eastern part of the state, such as late April into June, June on the Outer Banks, but mainly in June and July in the Mountains. It fruits shortly after flowering. | |
| Identification | This is a rather tall ladies'-tresses, often growing to 2 feet or more in height. Even so, the inflorescence is very narrow, though it can be well over 6 inches tall. There are a few grass-like basal leaves. The flowers, usually white but occasionally cream-colored, usually grow in a single rank, variously spiraled. The upper part of the stem is normally quite hairy, whereas S. praecox, which can bloom at the same time and grow in the same habitats, is mostly smooth to very slightly hairy on the upper part of the stem. The main separation character is the upper side of the lip, typically white in S. vernalis (or rarely with some green, but not with green veins/lines) but with obvious green lines on the upper side of the lip in S. praecox. Habitat can also be a clue, as a spring-blooming Spiranthes in a drier grassy field or roadside is much more likely to be S. vernalis than S. praecox. The somewhat similar S. lacera is a very late summer or fall blooming species, also often found in drier grassy sites. | |
| Taxonomic Comments | None
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| Other Common Name(s) | Twisted Ladies'-tresses | |
| State Rank | S3 [S4S5] | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | FACW link |
| USACE-emp | FAC link |
