| Author | Fernald | |
| Distribution | This is a poorly known species owing to its fairly recent split out from M. unifolia; the two species are extremely similar in appearance and as a result M. bayardii is likely overlooked. Thus the NC range of the species -- right now known only from the Piedmont in Rowan County plus Burke, Caldwell, and Watauga counties in the Mountains -- is certainly incomplete. In the Mountains, recorded from the vicinity of Table Rock Mountain (1890) and vicinity of Blowing Rock Mountain (1890-93). The Buncombe County specimen was actually from Burke County. For a detailed description, drawings, and distribution maps, see Catling (1991). Photos of a few plants from Macon County in 2022 on iNaturalist have been deemed by a few experts as this species; however, this location is much farther south than previous specimens, and there was considerable discussion, as supposedly the colony included individuals of M. unifolia, a questionable situation. The editors have chosen not to map this occurrence.
This species is known only from East Coast states, ranging from MA and southeastern NY south to western NC. There are no records known from KY or TN, and most states within the range have only a few county occurrences. | |
| Abundance | Apparently very rare, as only a few records are known, all more than a century old. Note that there is confusion over the identifications of specimens, and thus one or more of the specimen records might refer to M. unifolia. This is a Significantly Rare species, and whether it still exists in the state is uncertain. | |
| Habitat | This is an upland species over its range. The very similar M. unifolia grows mostly in moist forests and bottomlands. The North American Orchid Conservation Center website say the habitat over its range is "dry woodlands, pine barrens, and especially favors sandy and shallow soils." These habitats probably refer mostly to sites in the northeastern Coastal Plain, but the one definitive NC specimen was from Blowing Rock Mountain in Caldwell County. | |
| Phenology | This species blooms mostly from July to September -- perhaps mostly July or August in NC, and fruits shortly thereafter. Its blooming period is generally one or two months later than that of M. unifolia where both might be present. | |
| Identification | As expected, the identification of this species can be tricky, as M. unifolia is very similar. Each is a bright green to yellow-green plant overall; it grows to about 6-12 inches tall, with one large, broadly elliptic, entire leaf clasping the stem. The leaf is about 3-3.5 inches long, with a rounded tip. The inflorescence contains numerous very small green flowers, covering the top third to half of the stem. In this species, the flower stalk (pedicel) is short and only about 3-5 mm long, whereas M. unifolia has pedicels about 5-10 mm long. The flowers of this species have short and rounded lateral lobes to the lip, giving the lip a cordate or ovate look (very rounded), whereas the lateral lobes of the lip in M. unifolia are rather long and acute, giving the lip a more pointed look with straight sides. There are tiny characters on the flowers that are helpful to the experts. The main visual character may be a less dense inflorescence in this species, as compared with a dense clustering of flowers in M. unifolia, especially toward the tip of the stem. It may well be that the habitat of the orchid in question is the best separator in NC -- dry and upland forest in this species, versus moist ground -- boggy areas, bottomlands, and damp thickets, for M. unifolia. | |
| Taxonomic Comments | Most references, at least until one or two decades ago, did not list this entity, even as a variety; it was simply sunk within M. unifolia. However, it is generally conceded to be a good, valid species by recent authorities. The most comprehensive reference is Catling (1991).
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| Other Common Name(s) | Appalachian Adder's-mouth | |
| State Rank | S1 | |
| Global Rank | G1G2 | |
| State Status | SR-T | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
