| Author | Sommier & Levier | |
| Distribution | A single collection is known: a roadside drainage ditch in Watauga County, in 2011. See the original report in Poindexter et al. (2011).
Native of the Caucasus Mountains; in N.A. maritime Canada to Ont., south to NC, IL, MN; also OR, WA, B.C. | |
| Abundance | Very rare. Only a single plant was found and it was eradicated. This is a Federal Noxious Weed. | |
| Habitat | Roadside drainage ditch. | |
| Phenology | Flowering and fruiting June-August. | |
| Identification | Giant Hogweed is very robust, often growing 6-9 feet tall and with very thick hollow stems. Compared to the native Cow-parsnip (H. maximum), it has more rays per umbel (50-150 rays vs. 15-45 rays in the native species) and stems to a whopping 6 inches in diameter (vs. a maximum of 2 inches in diameter in H. maximum -- a very large plant in itself!). Both have highly dissected, large leaves and large, domed white umbels; most other umbel species have dissected leaves and white umbels, but these two species are giants compared with most others. | |
| Taxonomic Comments | | |
| Other Common Name(s) | | |
| State Rank | SE | |
| Global Rank | G4? | |
| State Status | | |
| US Status | | |
| USACE-agcp | FAC link |
| USACE-emp | FAC link |
