North America Native Plant

September 11 Stickleaf

Botanical name: Mentzelia memorabilis

USDA symbol: MEME7

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Mentzelia memorabalis N.H. Holmgren & P.K. Holmgren, orth. var. (MEME15)   

September 11 Stickleaf: A Critically Rare Arizona Native Meet the September 11 stickleaf (Mentzelia memorabilis), one of Arizona’s most elusive native plants. Also known as 9/11 blazingstar, this perennial shrub holds the distinction of being one of the rarest plants in the American Southwest. If you’re considering adding this plant ...

Rare plant alert!

Region: Conservation status by state

Status: S1: Status is uncertain but is somewhere between the following rankings: 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) ⚘

September 11 Stickleaf: A Critically Rare Arizona Native

Meet the September 11 stickleaf (Mentzelia memorabilis), one of Arizona’s most elusive native plants. Also known as 9/11 blazingstar, this perennial shrub holds the distinction of being one of the rarest plants in the American Southwest. If you’re considering adding this plant to your garden, there are some crucial things you need to know first.

What Makes This Plant So Special (and Rare)?

The September 11 stickleaf isn’t just uncommon—it’s critically imperiled. With a Global Conservation Status of S1, this means there are typically only five or fewer known populations in existence, with very few remaining individuals (fewer than 1,000 total). This extreme rarity makes it especially vulnerable to extinction.

As a low-growing perennial shrub, Mentzelia memorabilis typically stays under 1.5 feet tall and never exceeds 3 feet at maturity. Its compact growth habit and native Arizona heritage make it theoretically well-suited for desert landscaping, but its conservation status changes everything.

Where Does It Grow?

This rare gem is found exclusively in Arizona, making it a true regional endemic. Its limited distribution contributes significantly to its precarious conservation status.

Should You Plant September 11 Stickleaf?

Here’s where we need to have an honest conversation. While supporting native plants is always admirable, the September 11 stickleaf presents a unique ethical dilemma. Given its critically imperiled status, this plant should only be cultivated with extreme care and responsibility.

Our recommendation: Only consider planting this species if you can source it from verified conservation programs or authorized botanical institutions. Wild collection could contribute to the species’ extinction.

Growing Conditions (If You Can Source It Responsibly)

Based on its Arizona origins and membership in the Mentzelia family, the September 11 stickleaf likely prefers:

  • Full sun exposure
  • Well-draining, sandy or rocky soils
  • Minimal water once established
  • USDA hardiness zones 8-10 (estimated based on distribution)
  • Desert or xeriscape garden settings

Alternative Native Options

If you’re drawn to the idea of growing a native Arizona Mentzelia species, consider these more common alternatives that won’t impact rare populations:

  • Desert blazingstar (Mentzelia pumila)
  • White-stem blazingstar (Mentzelia albicaulis)
  • Desert evening primrose (Oenothera primiveris) – a similar-looking desert native

Supporting Conservation Instead

Rather than trying to grow this rare species, consider supporting organizations working to protect it in the wild. You can also help by:

  • Volunteering with native plant societies in Arizona
  • Donating to botanical gardens with conservation programs
  • Choosing more common native alternatives for your landscape
  • Spreading awareness about rare plant conservation

The Bottom Line

The September 11 stickleaf represents both the beauty and fragility of our native plant heritage. While its compact size and desert adaptation make it theoretically perfect for southwestern gardens, its critical rarity status means it belongs in conservation programs rather than home landscapes. By choosing more abundant native alternatives, you can still create a beautiful, ecologically valuable garden while helping protect one of Arizona’s most precious botanical treasures.

Remember: the best way to appreciate rare plants is often to leave them in their natural habitats where they can contribute to wild populations and ecological relationships that have developed over thousands of years.

September 11 Stickleaf

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

Violales

Family

Loasaceae Juss. - Loasa family

Genus

Mentzelia L. - blazingstar

Species

Mentzelia memorabilis N.H. Holmgren & P.K. Holmgren - September 11 stickleaf

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