North America Native Plant

Long Valley Tumblemustard

Botanical name: Thelypodiopsis ambigua var. erecta

USDA symbol: THAME

Life cycle: biennial

Habit: forb

Native status: Native to the lower 48 states  

Long Valley Tumblemustard: A Rare Desert Gem Worth Protecting Meet the Long Valley tumblemustard (Thelypodiopsis ambigua var. erecta), a fascinating little wildflower that’s as rare as it is resilient. This unassuming biennial forb might not win any flashy flower contests, but it holds a special place in the desert ecosystems ...

Rare plant alert!

Region: Conservation status by state

Status: S2S3T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ 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) ⚘ 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 ⚘

Long Valley Tumblemustard: A Rare Desert Gem Worth Protecting

Meet the Long Valley tumblemustard (Thelypodiopsis ambigua var. erecta), a fascinating little wildflower that’s as rare as it is resilient. This unassuming biennial forb might not win any flashy flower contests, but it holds a special place in the desert ecosystems of the American Southwest – and deserves our attention and respect.

What Makes This Plant Special?

Long Valley tumblemustard belongs to the mustard family and lives life as a biennial, meaning it takes two years to complete its life cycle. In its first year, it focuses on building up energy reserves, then flowers and sets seed in its second year before completing its journey. As a forb, it’s an herbaceous plant without woody stems – think of it as the desert’s version of a wildflower that knows how to survive in tough conditions.

What truly sets this plant apart, however, is its rarity. With a Global Conservation Status of S2S3T1, this variety is considered quite uncommon and potentially vulnerable. That makes every individual plant precious from a conservation standpoint.

Where You’ll Find It Growing Wild

This desert dweller calls Arizona and Utah home, where it has adapted to life in some pretty challenging conditions. As a native species of the lower 48 states, it’s perfectly suited to its harsh, arid environment – even if that means it’s not found in very many places.

Should You Grow Long Valley Tumblemustard?

Here’s where things get a bit complicated. While supporting native plants is always admirable, Long Valley tumblemustard’s rarity means we need to approach it thoughtfully. If you’re considering adding this plant to your garden, please keep these important points in mind:

  • Source responsibly: Only obtain seeds or plants from reputable native plant societies or conservation organizations
  • Never collect from the wild: Given its rarity, wild collection could harm already vulnerable populations
  • Consider your location: This plant is naturally adapted to Arizona and Utah conditions
  • Think conservation first: Your garden could help preserve this rare variety for future generations

Growing Conditions and Care

Unfortunately, specific growing information for this rare variety is quite limited. However, as a desert native adapted to Arizona and Utah conditions, it likely prefers:

  • Well-draining, sandy or rocky soils
  • Full sun exposure
  • Minimal water once established
  • Protection from excessive moisture

As a biennial, remember that patience is key – you won’t see flowers until the plant’s second year of growth.

The Conservation Angle

Growing Long Valley tumblemustard isn’t just about adding an unusual plant to your collection – it’s about participating in conservation efforts. Rare plants like this one face numerous challenges, from habitat loss to climate change. By growing it responsibly in appropriate climates, gardeners can help maintain genetic diversity and potentially provide seeds for future conservation efforts.

Alternatives to Consider

If you love the idea of supporting desert mustard family plants but want something more readily available, consider looking into other native Thelypodiopsis species or desert mustards that are more common in your area. Your local native plant society can guide you toward similar plants that might be easier to source and grow while still supporting regional ecosystems.

The Bottom Line

Long Valley tumblemustard represents the quiet beauty of desert adaptation and the importance of plant conservation. While it may not be the easiest plant to find or grow, it offers gardeners in appropriate climates a chance to participate in preserving a unique piece of our natural heritage. Just remember: with rarity comes responsibility, so always source ethically and grow with conservation in mind.

Long Valley Tumblemustard

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

Capparales

Family

Brassicaceae Burnett - Mustard family

Genus

Thelypodiopsis Rydb. - tumblemustard

Species

Thelypodiopsis ambigua (S. Watson) Al-Shehbaz - Long Valley tumblemustard

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