North America Native Plant

Railroad Valley Globemallow

Botanical name: Sphaeralcea caespitosa var. williamsiae

USDA symbol: SPCAW

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Railroad Valley Globemallow: A Rare Nevada Native Worth Protecting If you’re passionate about rare native plants, you might be intrigued by the Railroad Valley globemallow (Sphaeralcea caespitosa var. williamsiae). But before you rush to add this unique Nevada native to your garden wishlist, there are some important things you should ...

Rare plant alert!

Region: Conservation status by state

Status: S2T2: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Railroad Valley Globemallow: A Rare Nevada Native Worth Protecting

If you’re passionate about rare native plants, you might be intrigued by the Railroad Valley globemallow (Sphaeralcea caespitosa var. williamsiae). But before you rush to add this unique Nevada native to your garden wishlist, there are some important things you should know about this special little plant.

What Is Railroad Valley Globemallow?

Railroad Valley globemallow is a perennial forb herb – essentially a non-woody flowering plant that comes back year after year. Like other plants in its family, it lacks the thick, woody stems you’d find on shrubs or trees, instead producing softer herbaceous growth that emerges from buds at or below ground level each growing season.

Where Does It Call Home?

This globemallow variety is a true Nevada endemic, found only within the Silver State’s borders. As a native species to the lower 48 states, it has evolved specifically to thrive in Nevada’s unique desert conditions and landscapes.

The Rarity Factor: Why This Plant Needs Our Attention

Here’s where things get serious – Railroad Valley globemallow carries a Global Conservation Status of S2T2, which indicates it’s considered imperiled. This rarity status means the plant faces significant conservation challenges and has a limited distribution even within its native Nevada range.

What does this mean for gardeners? If you’re considering adding this plant to your landscape, it’s crucial to source it responsibly. Never collect plants or seeds from wild populations, as this can further threaten already vulnerable populations.

Should You Grow Railroad Valley Globemallow?

The honest answer is: probably not, unless you’re working with conservation professionals or have access to ethically propagated material. Given its imperiled status, this isn’t a plant for casual gardeners to experiment with. Instead, consider these alternatives:

  • Look into other Sphaeralcea species that are more common and readily available
  • Choose other Nevada native wildflowers that can provide similar ecological benefits
  • Support conservation efforts for rare plants through native plant societies

Growing Considerations

If you do have access to responsibly sourced Railroad Valley globemallow, remember that as a Nevada native, it’s likely adapted to arid conditions, well-draining soils, and the temperature extremes of high desert environments. However, specific growing requirements for this rare variety aren’t well-documented, making successful cultivation challenging even for experienced gardeners.

The Bottom Line

While Railroad Valley globemallow is undoubtedly a fascinating piece of Nevada’s natural heritage, its rarity makes it better suited for conservation efforts than home gardens. If you’re drawn to native globemallows, explore more common species that can give you similar beauty without the conservation concerns. Sometimes the best way to love a rare plant is to admire it from afar and support the professionals working to protect it in its natural habitat.

Remember, every rare plant that disappears takes with it millions of years of evolutionary adaptation. By choosing more common native alternatives, you can still create a beautiful, ecologically valuable garden while helping preserve Nevada’s rarest botanical treasures for future generations.

Railroad Valley Globemallow

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Malvales

Family

Malvaceae Juss. - Mallow family

Genus

Sphaeralcea A. St.-Hil. - globemallow

Species

Sphaeralcea caespitosa M.E. Jones - tufted globemallow

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