| Author | Michaux | |
| Distribution | NOTE: Weakley (2024) now has pulled out the formerly included lower Piedmont records into a new taxon, named as Euphorbia species 5. There is, however, an apparently valid record in the Mountains (Swain County), as it is only about two counties east of the main range in TN. A report from Granville County (NCNHP) is suspect and needs checking.
Primarily west of the main Appalachian chain in KY, TN, AL, and northwestern GA. The disjunct NC population is considered as an undescribed species by Weakley (2024). | |
| Abundance | If the Swain County specimen is valid as the "true" E. mercurialina, then apparently very rare if still present. | |
| Habitat | "Rich moist to dry forests over mafic or calcareous rocks." (Weakley 2024) |
| Phenology | Flowering and fruiting April-June. | |
| Identification | Cumberland Spurge is readily identified by its upright stem usually a foot or less tall, few but strongly ascending branches, and widely elliptical leaves up to 2.5 inches long, rounded at the tip (the Swain Co. specimen leaves are short-tapered). Leaves on the main stem are alternate, those on branches and inflorescence are opposite and sometimes whorled. The relatively few flowers are on long stalks, often nearly 1 inch long; each flower has short but wide white glandular appendages (resembling petals) -- looking like a narrow white ring surrounding the yellow-green reproductive parts. The species was possibly overlooked in the past as E. pubentissima, if not E. corollata; then again, it is possible (but not likely) that no botanist ever encountered this scarce species on the slopes in this part of the state. | |
| Taxonomic Comments | Weakley (2024) has pulled the lower Piedmont population out of this species owing to some differences between that and the main population in TN and westward. He has tentatively named that as Euphorbia species 5.
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| Other Common Name(s) | Cumberland Spurge | |
| State Rank | S2 [SU] | |
| Global Rank | G4 | |
| State Status | SC-V | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
