# Racemose Milkvetch (*astragalus racemosus*)

Racemose Milkvetch (Astragalus racemosus) is a robust, perennial wildflower native to the open prairies and badlands of central and western North America. Belonging to the diverse Fabaceae family, this species is highly specialized to thrive in soils that many other plants find inhospitable. It is famously classified as a selenium hyperaccumulator, meaning it actively draws up large concentrations of selenium from the ground, storing it within its tissues. While this adaptation renders the plant highly toxic to grazing livestock, it serves as a critical defense mechanism against hungry herbivores in the wild. This fascinating survival strategy makes it a key subject of ecological study. Its dense, drooping clusters of creamy-white flowers provide crucial nectar for native bumblebees, demonstrating its complex role as both a localized hazard and an ecological partner.

- **Category:** [Plants](https://www.snappit.app/explore/categories/plant)
- **Rarity:** Common
- **Danger:** 1/5 · Very low
- **Snaps:** 2
- **Habitat:** Found on open prairies, plains, clay badlands, and roadsides, typically growing in heavy, clay-rich soils high in selenium or gypsum.

![Racemose Milkvetch](https://inaturalist-open-data.s3.amazonaws.com/photos/148671197/medium.jpeg)

Photo: Matt Berger, CC BY 4.0 · [iNaturalist](https://www.inaturalist.org/photos/148671197)

## Appearance

This upright perennial typically grows between 30 to 100 centimeters tall, forming leafy clumps with sturdy, sometimes reddish-purple stems. Its leaves are pinnately compound, divided into numerous narrow, oblong leaflets of a grayish-green hue. The most distinguishing feature is the dense, one-sided clusters (racemes) of tubular, pea-like flowers. These blossoms are creamy-white to pale yellow, measuring about 1.5 to 2 centimeters long, and they hang gracefully downward from long stalks. After flowering, the plant produces swollen, triangular seed pods that dry to a light brown color.

## Taxonomy

- **Kingdom:** Plantae
- **Phylum:** Tracheophyta
- **Class:** Magnoliopsida
- **Order:** Fabales
- **Family:** Fabaceae
- **Genus:** Astragalus

## Interesting facts

- Because it only grows in soils rich in selenium, uranium prospectors historically used the presence of this plant to locate uranium-bearing geological formations.
- It is highly toxic to horses and cattle, causing a chronic poisoning known as 'alkali disease' or 'blind staggers,' which leads to hair loss and hoof deformities.
- When bruised or growing in hot weather, the plant releases a strong, garlic-like odor due to its high concentration of volatile selenium compounds.

## Special abilities

- **Selenium Hyperaccumulation:** Actively absorbs and concentrates selenium from the soil, making its tissues toxic to herbivores and reducing competition from sensitive plants nearby.
- **Atmospheric Nitrogen Fixation:** Partners with specialized underground rhizobia bacteria to convert atmospheric nitrogen into nutrients, enriching poor prairie soils.
- **Drought-Resistant Taproot:** Employs a deep, robust woody taproot that anchors the plant and accesses deep water reserves in arid grasslands.

## Measurements & details

- **Length:** 30-100 cm
- **Lifespan:** 3-10 years

## Diet & Feeding

As a photosynthetic autotroph, it synthesizes its own sugars using sunlight, carbon dioxide, and water while absorbing essential minerals from the soil.

- **Primary Foods:** Sunlight, Carbon Dioxide, Water, Soil Minerals

## Ecological connections

- **Mutualism:** Rhizobium bacteria (*Rhizobium leguminosarum*) — Forms a mutualistic relationship in the root nodules to convert atmospheric nitrogen into usable ammonia.
- **Mutualism:** Hunt's Bumblebee (*Bombus huntii*) — Feeds on the nectar of the flowers while acting as a primary pollinator.
- **Eaten by:** Astragalus Seed Beetle (*Acanthoscelides aureolus*) — Larvae of this beetle feed directly on the developing seeds inside the woody pods.

## Safety

**Danger:** 1/5 · Very low

No special safety notes yet.

## Frequently Asked Questions

### How to identify Racemose Milkvetch?

Start with the whole plant, then compare leaf arrangement, leaf edges, stems and any flowers or fruit. Opposite leaves grow in pairs; alternate leaves come one at a time along the stem. These details tell you far more together than a single green leaf does. Plant Identifier: upload a photo and compare the visible details.

### How long is Racemose Milkvetch?

30-100 cm

### How long does Racemose Milkvetch live?

3-10 years

### What does Racemose Milkvetch eat?

As a photosynthetic autotroph, it synthesizes its own sugars using sunlight, carbon dioxide, and water while absorbing essential minerals from the soil.

### Where is Racemose Milkvetch usually found?

Found on open prairies, plains, clay badlands, and roadsides, typically growing in heavy, clay-rich soils high in selenium or gypsum.

## Where to spot

- [Monument Rocks](https://www.snappit.app/guides/places/monument-rocks) — Kansas, US · Nature Reserve
- [Toadstool Geologic Park](https://www.snappit.app/guides/places/toadstool-geologic-park) — Nebraska, US · Nature Reserve

## More Plants

- [white snakeroot](https://www.snappit.app/explore/white-snakeroot) (*Ageratina altissima*)
- [tree-of-heaven](https://www.snappit.app/explore/tree-of-heaven) (*Ailanthus altissima*)
- [western sword fern](https://www.snappit.app/explore/western-sword-fern) (*Polystichum munitum*)
- [common milkweed](https://www.snappit.app/explore/common-milkweed) (*Asclepias syriaca*)

---

Source: [Racemose Milkvetch: Facts & Places to See — Snappit](https://www.snappit.app/explore/racemose-milkvetch)