North America Native Plant

Alyssumleaf Phlox

Botanical name: Phlox alyssifolia collina

USDA symbol: PHALC

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Alyssumleaf Phlox: A Rare Montana Native Worth Knowing If you’re a native plant enthusiast with a particular interest in regional flora, you might have stumbled across the name alyssumleaf phlox (Phlox alyssifolia collina). This intriguing perennial represents one of those botanical mysteries that keeps plant lovers on their toes – ...

Alyssumleaf Phlox: A Rare Montana Native Worth Knowing

If you’re a native plant enthusiast with a particular interest in regional flora, you might have stumbled across the name alyssumleaf phlox (Phlox alyssifolia collina). This intriguing perennial represents one of those botanical mysteries that keeps plant lovers on their toes – it’s documented as native to Montana, but finding detailed information about this specific variety can feel like searching for a needle in a haystack.

What Makes Alyssumleaf Phlox Special?

Alyssumleaf phlox belongs to the beloved phlox family, known for their often showy flowers and important role in native ecosystems. As a perennial forb herb, this plant lacks the woody tissue you’d find in shrubs or trees, instead maintaining its presence in the landscape through underground structures that survive winter and send up fresh growth each growing season.

The technical definition tells us it’s a vascular plant without significant woody tissue above or at the ground surface with perennating buds borne at or below the ground surface. In plain English? It’s a non-woody plant that comes back year after year from roots or underground stems.

Where Does It Call Home?

This particular phlox variety is documented as native to Montana, making it part of the treasure trove of plants that have adapted to the challenging conditions of Big Sky Country. As a native species to the lower 48 states with such a limited geographic range, it represents the kind of regional specialization that makes native plant gardening so fascinating.

The Challenge for Gardeners

Here’s where things get interesting – and a bit frustrating for those of us who love to dig deep into plant details. Despite its documented existence, finding specific information about alyssumleaf phlox’s growing requirements, appearance, or garden performance proves surprisingly difficult. This could mean several things:

  • It may be an extremely rare or limited variety
  • It could be a regional ecotype that hasn’t been widely studied
  • The taxonomic designation might be disputed or under review

What This Means for Your Garden

If you’re a Montana gardener intrigued by this native phlox, your best bet is to connect with local native plant societies, university extension programs, or botanical experts who specialize in regional flora. They may have insights into where this plant naturally occurs and whether it’s available through responsible sources.

Given the uncertainty surrounding this specific variety, consider exploring other well-documented native phlox species that are known to thrive in Montana gardens. Many phlox species offer beautiful spring or summer blooms, attract pollinators, and provide the ecological benefits that come with choosing native plants.

The Bigger Picture

Plants like alyssumleaf phlox remind us that there’s still so much to discover and document in the world of native flora. Even in our well-connected, information-rich world, some plants remain tantalizingly just out of reach for the average gardener.

If you do encounter this plant in the wild or find a reliable source, consider yourself lucky to witness a piece of Montana’s botanical heritage. Just remember to never collect from wild populations, and always work with reputable native plant sources who can verify both the plant’s identity and its responsible propagation.

Sometimes the most interesting native plants are the ones that keep a little mystery about them – and alyssumleaf phlox certainly fits that description.

Alyssumleaf Phlox

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

Solanales

Family

Polemoniaceae Juss. - Phlox family

Genus

Phlox L. - phlox

Species

Phlox alyssifolia Greene - alyssumleaf phlox

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