North America Native Plant

Rydberg’s Indian Breadroot

Botanical name: Pediomelum humile

USDA symbol: PEHU6

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Psoralea humilis (Rydb.) J.F. Macbr. (PSHU)  âš˜  Psoralea rydbergii Cory (PSRY)   

Rydberg’s Indian Breadroot: A Critically Rare Texas Treasure If you’re passionate about native plants and conservation, you’ve probably never heard of Rydberg’s Indian breadroot (Pediomelum humile) – and there’s a very good reason for that. This incredibly rare Texas native is so uncommon that it’s considered critically imperiled, making it ...

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) ⚘

Rydberg’s Indian Breadroot: A Critically Rare Texas Treasure

If you’re passionate about native plants and conservation, you’ve probably never heard of Rydberg’s Indian breadroot (Pediomelum humile) – and there’s a very good reason for that. This incredibly rare Texas native is so uncommon that it’s considered critically imperiled, making it one of the rarest wildflowers in the Lone Star State.

What Makes This Plant So Special?

Rydberg’s Indian breadroot is a perennial forb belonging to the legume family, which means it’s related to beans, peas, and other nitrogen-fixing plants. As a low-growing herbaceous plant, it lacks woody stems but returns year after year from its root system. You might also see it listed under its former scientific names, Psoralea humilis or Psoralea rydbergii, in older botanical references.

This little-known plant produces the characteristic pea-like flowers typical of legumes, likely in shades of purple or blue, though detailed descriptions of its appearance are limited due to its extreme rarity.

Where Does It Call Home?

Rydberg’s Indian breadroot is found exclusively in Texas, making it a true Lone Star State endemic. Its distribution is extremely limited, which contributes significantly to its precarious conservation status.

A Plant in Crisis

Here’s where things get serious: Pediomelum humile has a Global Conservation Status of S1, meaning it’s critically imperiled. This classification indicates that there are typically five or fewer known occurrences of this species, with very few remaining individuals – we’re talking fewer than 1,000 plants total. This makes it one of Texas’s most endangered wildflowers.

Should You Grow Rydberg’s Indian Breadroot?

The short answer is: probably not, and definitely not without extreme caution. Given its critically imperiled status, this plant should only be cultivated under very specific circumstances:

  • Only use seeds or plants from verified, responsibly managed sources
  • Never collect from wild populations
  • Consider it only if you’re involved in legitimate conservation efforts
  • Ensure you have proper permits if required

Instead of growing this rare species, consider planting other native Texas legumes that can provide similar ecological benefits without the conservation concerns.

Growing Conditions and Care

While specific growing requirements for Rydberg’s Indian breadroot aren’t well documented due to its rarity, we can make educated guesses based on its Texas habitat and legume family characteristics:

  • Likely thrives in well-drained soils
  • Probably prefers full sun exposure
  • Expected to be drought-tolerant once established
  • Suitable for USDA hardiness zones 8-9
  • May benefit from minimal disturbance once planted

Conservation Value

As a native legume, Rydberg’s Indian breadroot likely provides valuable ecosystem services when present, including nitrogen fixation and pollinator habitat. Its flowers would naturally attract native bees and other small pollinators, contributing to local biodiversity.

The Bottom Line

Rydberg’s Indian breadroot represents the fragile nature of our native plant heritage. While it’s not a plant for the average gardener, its story serves as a powerful reminder of why native plant conservation matters. If you’re interested in supporting Texas natives, focus on more common species that can thrive in cultivation while leaving rare treasures like this one to conservation professionals.

Remember: the best way to appreciate critically rare plants like Rydberg’s Indian breadroot is to support habitat conservation efforts and choose abundant native alternatives for your garden. Every native plant you grow – no matter how common – contributes to preserving Texas’s natural heritage.

Rydberg’s Indian Breadroot

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

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Pediomelum Rydb. - Indian breadroot

Species

Pediomelum humile Rydb. - Rydberg's Indian breadroot

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