| Author | (L.) Hooker | |
| Distribution | North American species formerly in the genus Prenanthes have now been assigned to the genus Nabalus. Sorrie & LeBlond (2025) indicate that records of the old "Prenanthes alba ssp. pallida" in the NC outer Coastal Plain are now assignable to Nabalus albus var. stramineus. See the separate account for that variety. Only Nabalus albus var. albus, is shown on the range map below.
ME to Man., south to NC, WV, MO, and AR. | |
| Abundance | Apparently rare, with specimens known from 7 counties, and reports from 4 others. This is a State Special Concern species. The NCNHP's State Rank for the full species is S1S2, which might well also apply to the abundance rank of this Mountain taxon. However, because of some taxonomic uncertainties, biologists do not seem to have a good handle on its abundance and distribution. | |
| Habitat | Montane forests and woodlands, especially in high pH soils. | |
| Phenology | Flowering and fruiting July-October. | |
| Identification | Rattlesnake-roots are characterized by nodding heads of ray florets only, alternate leaves that are roughly triangular and irregularly lobed and/or toothed, and milky juice. White Rattlesnake-root grows 2-5 feet tall and has cinnamon colored pappus (feathery hairs attached to seeds), and white to pale pink florets. | |
| Taxonomic Comments | Outer Coastal Plain plants, formerly Prenanthes alba ssp. pallida Milstead, have been re-examined and do not belong within Nabalus trifoliolatus; moreover, Milstead did not validly publish that name. Those plants have been given a new name: N. albus var. stramineus Sorrie & LeBlond.
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| Other Common Name(s) | Northern Rattlesnake-root, White Lettuce | |
| State Rank | S1S2 | |
| Global Rank | G5 [G5T5] | |
| State Status | [SC-V] | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
