North America Native Plant

Roan Mountain Rattlesnakeroot

Botanical name: Prenanthes roanensis

USDA symbol: PRRO2

Life cycle: biennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Nabalus cylindricus Small (NACY)  âš˜  Nabalus roanensis Chickering (NARO3)  âš˜  Prenanthes cylindrica (Small) E.L. Braun (PRCY)   

Roan Mountain Rattlesnakeroot: A Rare Appalachian Treasure Worth Protecting If you’re drawn to rare and unusual native plants, you might have encountered Roan Mountain rattlesnakeroot (Prenanthes roanensis) in your research. This intriguing biennial forb is one of the Southern Appalachian Mountains’ most distinctive wildflowers, but before you rush to add ...

Rare plant alert!

Region: Conservation status by state

Status: S3: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

Roan Mountain Rattlesnakeroot: A Rare Appalachian Treasure Worth Protecting

If you’re drawn to rare and unusual native plants, you might have encountered Roan Mountain rattlesnakeroot (Prenanthes roanensis) in your research. This intriguing biennial forb is one of the Southern Appalachian Mountains’ most distinctive wildflowers, but before you rush to add it to your garden, there are some important things you should know about this vulnerable species.

What Makes This Plant Special

Roan Mountain rattlesnakeroot is a true mountain specialist, found only in the high-elevation areas of North Carolina, Tennessee, and Virginia. As a biennial forb, it spends its first year developing a rosette of leaves close to the ground, then sends up tall flowering stems in its second year before completing its life cycle.

The plant produces delicate spikes of small, pale yellow to white flowers that create an ethereal appearance in late summer. Its narrow leaves and upright growth habit give it a distinctive silhouette that stands out among other native wildflowers.

A Conservation Concern

Here’s where things get serious: Roan Mountain rattlesnakeroot has a Global Conservation Status of S3, meaning it’s considered vulnerable throughout its range. This classification indicates the species is at risk due to its limited distribution and small population sizes. Typically, there are only 21 to 100 known occurrences of this plant, making it quite rare in the wild.

Important: If you’re interested in growing this plant, please only obtain seeds or plants from reputable native plant nurseries that source their material responsibly. Never collect from wild populations, as this could further threaten already vulnerable populations.

Growing Roan Mountain Rattlesnakeroot

Let’s be honest—this isn’t a plant for beginners or typical garden conditions. Roan Mountain rattlesnakeroot has evolved in very specific high-elevation environments, and replicating these conditions in most home gardens is challenging.

Ideal Growing Conditions

  • Cool, moist, well-drained soils
  • Partial shade to filtered sunlight
  • High elevation or naturally cool microclimates
  • USDA Hardiness Zones 5-7
  • Consistent moisture without waterlogging

Garden Role and Design

If you can provide the right conditions, Roan Mountain rattlesnakeroot works best in:

  • Native plant gardens focused on Appalachian species
  • Rock gardens with cool, moist conditions
  • Naturalized woodland edges
  • Conservation-focused plantings

Wildlife and Pollinator Benefits

Like other members of the aster family, Roan Mountain rattlesnakeroot attracts butterflies and other small pollinators when it blooms in late summer. Its flowers provide nectar for various insects, contributing to the biodiversity of mountain ecosystems.

Should You Grow It?

The decision to grow Roan Mountain rattlesnakeroot should be made carefully. Consider these factors:

Reasons to grow it:

  • Supporting conservation of a rare native species
  • Adding an authentic Appalachian plant to your collection
  • Contributing to pollinator habitat
  • Educational value about rare plants

Challenges to consider:

  • Very specific growing requirements
  • Limited availability from ethical sources
  • May not thrive outside its natural range
  • Biennial lifecycle requires patience

The Bottom Line

Roan Mountain rattlesnakeroot is a fascinating piece of Appalachian natural heritage that deserves our respect and protection. While it can be grown in gardens under the right conditions, it’s not a casual choice for most gardeners. If you’re passionate about rare native plants and can provide appropriate growing conditions, consider it a rewarding challenge—but always source your plants responsibly.

For most gardeners interested in supporting native wildlife and creating beautiful landscapes, there are many more adaptable native alternatives that can provide similar benefits without the conservation concerns. However, for those dedicated to preserving rare species and willing to meet this plant’s specific needs, Roan Mountain rattlesnakeroot offers a unique opportunity to participate in botanical conservation right in your own garden.

Roan Mountain Rattlesnakeroot

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Prenanthes L. - rattlesnakeroot

Species

Prenanthes roanensis (Chickering) Chickering - Roan Mountain rattlesnakeroot

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA