Non-native Plants

Stinknet

Oncosiphon piluliferum

USDA symbol: ONPI

annual forb

Lower 48 states: non-native, naturalized

If you’ve ever wandered through the southwestern United States and noticed small, bright yellow ball-shaped flowers carpeting the ground in spring, you’ve likely encountered stinknet (Oncosiphon piluliferum). This South African native has made quite a name for itself in American gardens – though not always for the best reasons. Stinknet ...

Stinknet: A Controversial Ground Cover for Water-Wise Gardens

If you’ve ever wandered through the southwestern United States and noticed small, bright yellow ball-shaped flowers carpeting the ground in spring, you’ve likely encountered stinknet (Oncosiphon piluliferum). This South African native has made quite a name for itself in American gardens – though not always for the best reasons.

What is Stinknet?

Stinknet is an annual forb that belongs to the sunflower family. Despite its less-than-flattering common name, this plant produces cheerful clusters of tiny, globe-shaped yellow flowers that can brighten up dry landscapes. The plant gets its distinctive name from the pungent odor it releases when crushed or disturbed – definitely not something you’d want to use in a cutting garden!

You might also see this plant listed under its botanical synonym Matricaria globifera in older gardening references, but Oncosiphon piluliferum is the currently accepted scientific name.

Where Does Stinknet Grow?

Originally from South Africa, stinknet has established itself as a non-native species in the southwestern United States. You’ll find it growing wild in Arizona and California, where it has adapted remarkably well to the arid climate. The plant typically thrives in areas that are usually dry but can occasionally handle some moisture, making it quite versatile in Mediterranean and desert climates.

  • Species observed
  • No observations

Should You Plant Stinknet in Your Garden?

This is where things get a bit complicated. While stinknet can be an effective ground cover for water-wise gardens, its aggressive self-seeding nature means it can quickly spread beyond where you originally planted it. Here are some considerations:

Potential Benefits:

  • Extremely drought tolerant once established
  • Provides bright yellow spring color
  • Attracts small pollinators and beneficial insects
  • Requires minimal care and maintenance
  • Works well in USDA hardiness zones 9-11

Potential Drawbacks:

  • Can spread aggressively through self-seeding
  • Unpleasant odor when disturbed
  • May outcompete native plants
  • Considered weedy in many areas

Growing Conditions and Care

If you decide to try stinknet in your garden, it’s remarkably easy to grow. This tough little plant prefers full sun and well-draining soil – the more challenging the conditions, the better it seems to perform. It’s perfectly suited for those neglected corners of your yard where other plants struggle.

Stinknet requires very little water once established and actually prefers lean, poor soils over rich, fertile ones. The plant will self-seed readily, so be prepared for it to pop up in unexpected places the following season.

Native Alternatives to Consider

Given stinknet’s aggressive nature, you might want to consider native alternatives that provide similar benefits without the potential for unwanted spread:

  • Desert marigold (Baileya multiradiata) for bright yellow flowers
  • Brittlebush (Encelia farinosa) for drought tolerance and pollinator appeal
  • Desert lupine (Lupinus sparsiflorus) for colorful spring blooms
  • Ghost plant (Graptopetalum paraguayense) for low-maintenance ground cover

The Bottom Line

Stinknet can be an effective plant for extremely challenging growing conditions, but its aggressive nature means it’s not the best choice for most home gardens. If you’re dealing with a particularly difficult spot where nothing else will grow, it might be worth considering – just be prepared to manage its spread. For most gardeners, choosing native alternatives will provide similar benefits while supporting local ecosystems and avoiding potential headaches down the road.

Remember, the best gardens work with nature rather than against it, so choosing plants that naturally belong in your area is usually the wisest path forward.

Oncosiphon piluliferum is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Oncosiphon piluliferum is also known as:

Matricaria globifera Fenzl ex | USDA symbol: MAGL13

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" — matching plants to their ideal growing conditions, so they'll thrive with less care and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection can be if you don't have the right information. While tags on nursery plants list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. You might be surprised to learn that popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. The table below gives insight into the preferred growing conditions of this plant throughout its geographical distribution.

Region
Preferred Habitat

Arid West (AZ, CA, CO, ID, MT, NV, NM, OR, TX, UT, WA, WY)

Facultative Upland

Western Mountains, Valleys, and Coast (AZ, CA, CO, ID, MT, NV, NM, OR, SD, UT, WA, WY)

Facultative Upland
Wetland Glossary
Obligate Wetland
Facultative Wetland
Facultative
Facultative Upland
Obligate Upland
Almost always occurs in wetlands
Usually occurs in wetlands but may occur in non-wetlands
Can occur in wetlands and non-wetlands
Usually occurs in non-wetlands but may occur in wetlands
Almost never occurs in wetlands

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Asteridae
Order: Asterales
Family: Asteraceae Bercht. & J. Presl - Aster family
Genus: Oncosiphon Källersjö - oncosiphon

Species: Oncosiphon piluliferum (L. f.) Källersjö - stinknet

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