North America Native Plant

Southern Flax

Botanical name: Linum australe var. glandulosum

USDA symbol: LIAUG

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Mesynium australe (A. Heller) W.A. Weber ssp. glandulosum (C.M. Rogers) W.A. Weber (MEAUG)   

Southern Flax: A Rare Southwestern Native Worth Knowing About If you’re a native plant enthusiast exploring the diverse flora of the American Southwest, you may have stumbled across Linum australe var. glandulosum, commonly known as southern flax. This intriguing little annual represents one of nature’s more elusive native wildflowers, found ...

Southern Flax: A Rare Southwestern Native Worth Knowing About

If you’re a native plant enthusiast exploring the diverse flora of the American Southwest, you may have stumbled across Linum australe var. glandulosum, commonly known as southern flax. This intriguing little annual represents one of nature’s more elusive native wildflowers, found in just two states and carrying an air of botanical mystery that makes it fascinating for plant lovers and naturalists alike.

What Is Southern Flax?

Southern flax is an annual forb – essentially a soft-stemmed herbaceous plant that completes its entire life cycle in one growing season. As a member of the flax family (Linaceae), it shares genetic heritage with the more familiar flax plants used for linen production, though this southwestern variety has evolved its own unique characteristics adapted to arid climates.

Unlike woody shrubs or trees, southern flax lacks significant woody tissue above ground. Instead, it grows as a tender annual that emerges, flowers, sets seed, and dies back all within a single year, with its growing buds positioned at or just below ground level.

Where Does Southern Flax Grow?

This native plant has a remarkably limited natural range, occurring only in Arizona and Texas. Its restricted distribution makes it something of a botanical treasure – a true regional endemic that represents the unique flora of the American Southwest. The fact that it’s found in just two states speaks to its specific habitat requirements and adaptation to particular environmental conditions.

The Challenge of Growing Southern Flax

Here’s where things get interesting – and a bit challenging for the home gardener. Southern flax falls into that category of native plants that botanists know exists but about which detailed cultivation information remains surprisingly scarce. Unlike popular native plants that have been extensively studied and cultivated, this variety of flax hasn’t made its way into mainstream horticulture guides or seed catalogs.

What we do know is that as a native of Arizona and Texas, it’s likely adapted to:

  • Hot, dry summers
  • Well-draining soils
  • Full sun conditions
  • Minimal water once established

Should You Try Growing It?

The honest answer is: it depends on your gardening philosophy and goals. If you’re someone who enjoys supporting regional biodiversity and doesn’t mind a bit of horticultural adventure, southern flax could be an interesting addition to a native plant collection – provided you can source seeds responsibly.

However, there are some important considerations:

  • Availability: Seeds or plants may be extremely difficult to find through commercial sources
  • Growing requirements: Specific cultivation needs aren’t well-documented
  • Success rates: Without established growing protocols, success may be unpredictable

Alternative Native Flax Options

If the idea of growing native flax appeals to you but southern flax proves too elusive, consider these more readily available alternatives:

  • Wild blue flax (Linum lewisii) – widely available and stunning in wildflower gardens
  • Prairie flax (Linum sulcatum) – another native option with broader cultivation information
  • Other native Texas or Arizona wildflowers that share similar growing conditions

The Bigger Picture

Southern flax represents something important in the world of native plants: regional diversity and the incredible specificity of nature’s adaptations. Even if you never grow this particular variety, knowing it exists reminds us of the rich tapestry of native species that call our landscapes home.

For gardeners in Arizona and Texas, keep an eye out for southern flax in its natural habitat. Observing how and where it grows can provide valuable insights into its preferences and potentially inform future cultivation attempts. Sometimes the best way to appreciate a rare native plant is simply to know it’s out there, quietly doing its part in the ecosystem.

Whether or not southern flax ever makes it into your garden, it serves as a wonderful example of why protecting native plant habitats matters – because you never know what botanical treasures might be growing right in your backyard.

Southern Flax

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Linales

Family

Linaceae DC. ex Perleb - Flax family

Genus

Linum L. - flax

Species

Linum australe A. Heller - southern flax

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