North America Native Plant

Mexican Skullcap

Botanical name: Scutellaria potosina platyphylla

USDA symbol: SCPOP2

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Mexican Skullcap: A Rare Native Gem for Arizona Gardens If you’re an Arizona gardener with a passion for rare native plants, you might have stumbled across the intriguing Mexican skullcap (Scutellaria potosina platyphylla). This lesser-known perennial herb represents one of those special native species that makes you feel like you’ve ...

Rare plant alert!

Region: Conservation status by state

Status: S3S5TU: 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 ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Mexican Skullcap: A Rare Native Gem for Arizona Gardens

If you’re an Arizona gardener with a passion for rare native plants, you might have stumbled across the intriguing Mexican skullcap (Scutellaria potosina platyphylla). This lesser-known perennial herb represents one of those special native species that makes you feel like you’ve discovered a botanical treasure – though finding reliable information about it can be quite the adventure!

What is Mexican Skullcap?

Mexican skullcap is a native perennial forb that belongs to the mint family. As a forb, it’s a non-woody vascular plant that lacks the thick, woody stems you’d find on shrubs or trees. Instead, it maintains its perennial nature through underground structures, with new growth emerging each growing season. This plant is truly a local specialty – it’s found naturally only in Arizona within the United States.

Where Does It Grow?

This native beauty calls Arizona home, making it a true regional endemic within the lower 48 states. Its limited distribution makes it a special addition to southwestern native plant gardens, though this also means it’s not something you’ll find at your typical garden center.

A Word of Caution: Rarity Status

Here’s where things get interesting – and a bit concerning. Mexican skullcap has a conservation status that’s currently listed as undefined, which essentially means experts aren’t quite sure about its population stability. This uncertainty, combined with its limited distribution, means we should approach this plant with extra care and respect.

If you’re considering adding this species to your garden, please ensure you source it responsibly. Never collect plants from the wild, and only purchase from reputable native plant nurseries that can verify their propagation methods. Better yet, consider joining local native plant societies or botanical gardens that might have seed exchange programs.

Why Grow Mexican Skullcap?

Despite the limited information available, there are several compelling reasons to consider this native gem:

  • It’s a true Arizona native, perfectly adapted to local conditions
  • As a member of the mint family, it likely provides nectar for native pollinators
  • Its perennial nature means it returns year after year once established
  • Growing rare natives helps preserve genetic diversity in cultivation
  • It adds authenticity to native landscape designs

Growing Conditions and Care

Here’s where we encounter the challenge of growing lesser-known natives – specific growing information for this exact species is quite limited. However, based on its Arizona distribution and relationship to other skullcaps, we can make some educated assumptions:

  • Likely thrives in USDA hardiness zones 8-10
  • Probably prefers well-draining soils typical of desert and semi-desert regions
  • May appreciate some afternoon shade in extreme heat
  • Drought tolerance is likely once established
  • Minimal water requirements after establishment period

Garden Design Ideas

Mexican skullcap would be perfect for:

  • Native plant collections and botanical gardens
  • Rock gardens with good drainage
  • Pollinator gardens focused on southwestern species
  • Conservation gardens dedicated to rare plants
  • Educational landscapes showcasing Arizona’s botanical heritage

The Bottom Line

Mexican skullcap represents both an opportunity and a responsibility. While it’s a fascinating native species that could add unique character to appropriate gardens, its uncertain conservation status means we need to approach it thoughtfully. If you can source it responsibly and have suitable growing conditions, it could be a wonderful addition to a specialized native plant collection.

However, if you’re looking for more readily available alternatives, consider exploring other native Arizona members of the mint family or consulting with local native plant experts who can recommend similar species with better-documented growing requirements and more stable populations.

Remember, every native plant we successfully grow and propagate in our gardens contributes to preserving our local botanical heritage – and with species like Mexican skullcap, that contribution feels especially meaningful.

Mexican Skullcap

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

Lamiaceae Martinov - Mint family

Genus

Scutellaria L. - skullcap

Species

Scutellaria potosina Brandegee - Mexican skullcap

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