North America Native Plant

Thompson’s Cryptantha

Botanical name: Cryptantha thompsonii

USDA symbol: CRTH3

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Oreocarya thompsonii (I.M. Johnst.) Abrams (ORTH2)   

Thompson’s Cryptantha: A Rare Pacific Northwest Gem Worth Protecting Meet Thompson’s cryptantha (Cryptantha thompsonii), a delicate perennial wildflower that’s as rare as it is charming. This little-known native of the Pacific Northwest deserves a spot in the conversation about regional native plants, though finding it might require some detective work! ...

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 ⚘

Thompson’s Cryptantha: A Rare Pacific Northwest Gem Worth Protecting

Meet Thompson’s cryptantha (Cryptantha thompsonii), a delicate perennial wildflower that’s as rare as it is charming. This little-known native of the Pacific Northwest deserves a spot in the conversation about regional native plants, though finding it might require some detective work!

What Makes Thompson’s Cryptantha Special

Thompson’s cryptantha is a herbaceous perennial that belongs to the borage family, sharing DNA with forget-me-nots and other beloved garden flowers. But unlike its more common cousins, this Pacific Northwest native is quite the wallflower – in the best possible way.

You might also see this plant listed under its botanical synonym Oreocarya thompsonii, but don’t let the name changes fool you. Whether you call it Thompson’s cryptantha or use its scientific name Cryptantha thompsonii, you’re talking about the same special plant.

Where Thompson’s Cryptantha Calls Home

This native beauty has a rather exclusive address – you’ll only find it naturally growing in Oregon and Washington. It’s what botanists call an endemic species, meaning it’s perfectly adapted to the unique conditions of the Pacific Northwest but hasn’t spread beyond this region.

A Word of Caution: Rarity Matters

Before you start dreaming of adding Thompson’s cryptantha to your garden, there’s something important you need to know. This plant has a Global Conservation Status of S3, which means it’s considered vulnerable. With only an estimated 21 to 100 occurrences or between 3,000 and 10,000 individual plants in the wild, every single Thompson’s cryptantha counts.

If you’re determined to grow this rare beauty, please only source it from reputable native plant nurseries that can guarantee their stock comes from ethically propagated material – never from wild collection.

Garden Appeal and Design Potential

Thompson’s cryptantha produces small white flowers arranged in the characteristic coiled clusters typical of the borage family. These delicate blooms appear on a low-growing herbaceous perennial that won’t compete with showier garden stars but adds subtle charm to specialized plantings.

This plant works best in:

  • Native plant gardens focused on Pacific Northwest species
  • Rock gardens with excellent drainage
  • Naturalized areas that mimic native habitats
  • Conservation gardens dedicated to rare species

Growing Conditions and Care

Like many Pacific Northwest natives, Thompson’s cryptantha likely prefers well-draining soils and can handle some drought once established. Based on its natural range, it should be hardy in USDA zones 6-9, making it suitable for most temperate gardens in its native region.

Key growing tips:

  • Provide excellent drainage – soggy soil is likely a death sentence
  • Full sun to partial shade exposure
  • Minimal watering once established
  • Allow natural dormancy periods

Supporting Pollinators

While we don’t have extensive research on Thompson’s cryptantha specifically, plants in the Cryptantha genus typically attract small native bees and other specialized pollinators. By growing rare natives like this one, you’re potentially providing crucial habitat for equally specialized and possibly rare pollinator species.

The Bottom Line

Thompson’s cryptantha represents something special in the world of native gardening – a chance to participate in conservation while creating beautiful, ecologically meaningful landscapes. However, its rarity means this isn’t a plant for casual gardeners.

If you’re passionate about Pacific Northwest natives and committed to responsible gardening practices, Thompson’s cryptantha could be a meaningful addition to your collection. Just remember: source responsibly, grow carefully, and consider yourself a steward of something truly precious.

For most gardeners interested in supporting native ecosystems, consider starting with more common Pacific Northwest natives that offer similar ecological benefits without the conservation concerns. Your local native plant society can point you toward abundant species that are just as beautiful and much easier on both your conscience and your wallet!

Thompson’s Cryptantha

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

Lamiales

Family

Boraginaceae Juss. - Borage family

Genus

Cryptantha Lehm. ex G. Don - cryptantha

Species

Cryptantha thompsonii I.M. Johnst. - Thompson's cryptantha

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