North America Native Plant

Rush Lemonweed

Botanical name: Psoralidium junceum

USDA symbol: PSJU2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Psoralea juncea Eastw. (PSJU)   

Rush Lemonweed: A Hidden Gem for Desert Gardens If you’re looking for a unique native plant that embodies the understated elegance of the American Southwest, rush lemonweed (Psoralidium junceum) might just be your next garden treasure. This slender perennial brings a touch of wild desert beauty to specialized landscapes, though ...

Rare plant alert!

Region: Conservation status by state

Status: S3: 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 ⚘

Rush Lemonweed: A Hidden Gem for Desert Gardens

If you’re looking for a unique native plant that embodies the understated elegance of the American Southwest, rush lemonweed (Psoralidium junceum) might just be your next garden treasure. This slender perennial brings a touch of wild desert beauty to specialized landscapes, though its rarity makes it a plant that deserves our special attention and care.

What Makes Rush Lemonweed Special?

Rush lemonweed is a native perennial forb that’s perfectly adapted to life in the arid Southwest. Despite its common name, this plant isn’t actually related to rushes at all—it’s a member of the legume family. The rush part comes from its slender, almost grass-like appearance, while lemonweed likely refers to its small, bright yellow flowers that bloom along the stems.

This herbaceous perennial has a minimalist beauty that appeals to gardeners who appreciate subtle, naturalistic plantings over flashy displays. Its delicate yellow pea-like flowers and slender growth habit create an airy, textural element in desert landscapes.

Where Rush Lemonweed Calls Home

Rush lemonweed is native to the southwestern United States, with documented populations in Arizona and Utah. This limited geographic distribution reflects the plant’s specialized habitat requirements and contributes to its current conservation status.

A Word of Caution: Rarity Matters

Before we dive into growing tips, there’s something important you should know: rush lemonweed has a Global Conservation Status of S3, meaning it’s considered vulnerable in the wild. With typically only 21 to 100 occurrences and between 3,000 and 10,000 individuals total, this plant is genuinely rare.

What does this mean for gardeners? If you’re interested in growing rush lemonweed, it’s crucial to source your plants or seeds responsibly. Never collect from wild populations, and only purchase from reputable native plant nurseries that can guarantee their stock comes from ethical propagation programs.

Is Rush Lemonweed Right for Your Garden?

Rush lemonweed isn’t for every garden—and that’s perfectly okay! This specialized native is best suited for:

  • Desert and xeriscape gardens in appropriate climate zones
  • Native plant collections and botanical gardens
  • Rock gardens with excellent drainage
  • Naturalistic landscapes that mimic southwestern ecosystems
  • Conservation-minded gardening projects

If you live outside of USDA hardiness zones 4-9 or in areas with high rainfall and humidity, rush lemonweed probably isn’t the right choice for your landscape. Instead, consider other native legumes that are better adapted to your local conditions.

Growing Rush Lemonweed Successfully

If you’re in the right climate zone and have access to ethically sourced plants, rush lemonweed can be a rewarding addition to specialized gardens. Here’s what this desert native needs to thrive:

Essential Growing Conditions

  • Sunlight: Full sun is absolutely essential
  • Soil: Well-draining, sandy or rocky soil that mimics its natural desert habitat
  • Water: Drought tolerant once established; avoid overwatering at all costs
  • Climate: Arid to semi-arid conditions with low humidity

Planting and Care Tips

  • Plant in spring after the last frost danger has passed
  • Ensure excellent drainage—this plant will not tolerate wet feet
  • Water sparingly during the first year to help establish roots, then rely on natural rainfall
  • Avoid fertilizing, as desert natives often perform better in nutrient-poor soils
  • Mulch lightly with gravel or small stones rather than organic mulch

Supporting Pollinators and Wildlife

As a native legume, rush lemonweed likely provides nectar and pollen for specialized native bees and other small pollinators that have co-evolved with southwestern flora. By growing this plant (responsibly sourced, of course), you’re helping support the intricate web of relationships that make desert ecosystems so remarkable.

The Bottom Line

Rush lemonweed is a plant for the dedicated native plant enthusiast who lives in the appropriate climate zone and can commit to responsible sourcing and growing practices. While it’s not a plant for every garden, it offers the opportunity to grow a genuinely rare native species while contributing to conservation efforts.

If you’re not in the southwestern U.S. or don’t have the right growing conditions, consider exploring other native legumes that are better suited to your area. Every region has its own beautiful native plants that can provide similar ecological benefits while being more appropriate for local conditions.

Remember: the best native plant for your garden is always one that’s actually native to your specific region and can thrive in the conditions you can provide!

Rush Lemonweed

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

Psoralidium Rydb. - scurfpea

Species

Psoralidium junceum (Eastw.) Rydb. - rush lemonweed

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