North America Native Plant

Arrow Thelypody

Botanical name: Thelypodium sagittatum

USDA symbol: THSA2

Life cycle: biennial

Habit: forb

Native status: Native to the lower 48 states  

Arrow Thelypody: A Hidden Gem for Western Native Plant Gardens If you’re passionate about native plants but tired of the usual suspects, let me introduce you to arrow thelypody (Thelypodium sagittatum). This unassuming member of the mustard family might not win any beauty contests, but it’s got character and plays ...

Arrow Thelypody: A Hidden Gem for Western Native Plant Gardens

If you’re passionate about native plants but tired of the usual suspects, let me introduce you to arrow thelypody (Thelypodium sagittatum). This unassuming member of the mustard family might not win any beauty contests, but it’s got character and plays an important role in western ecosystems. Plus, it’s one of those plants that makes you sound like a real plant nerd when you casually mention it at garden parties!

What Exactly Is Arrow Thelypody?

Arrow thelypody is a native biennial or perennial forb – that’s botanist-speak for a non-woody plant that comes back year after year. Think of it as the reliable friend in your garden who might not be flashy but always shows up when you need them. This plant belongs to the mustard family, which explains its small, four-petaled flowers that cluster together in elongated spikes.

As a forb, arrow thelypody lacks the woody stems of shrubs and trees, instead growing from buds at or below ground level. This growth habit makes it perfect for filling in gaps in your native plant garden without overwhelming more delicate neighbors.

Where Does Arrow Thelypody Call Home?

This western native has quite an impressive range across the American West. You’ll find arrow thelypody growing naturally in Colorado, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming. It’s truly a plant of the mountain west, adapted to the unique challenges of high-altitude and arid environments.

The Wet-or-Dry Personality

Here’s where arrow thelypody gets interesting – it’s got a bit of a split personality when it comes to water. In some regions, it’s considered a wetland plant that loves moist soils, while in others, it’s more of an upland species that tolerates drier conditions. This adaptability makes it a fantastic choice for gardeners dealing with variable moisture conditions or those tricky spots where water availability changes throughout the season.

Why You Might Want to Grow Arrow Thelypody

Let’s be honest – arrow thelypody isn’t going to stop traffic with its looks. Its small white to pale yellow flowers are modest rather than showy. But here’s why you should consider giving it a spot in your garden:

  • It’s a true western native that supports local ecosystems
  • Adaptable to various moisture conditions
  • Low-maintenance once established
  • Attracts small pollinators like native bees and beneficial flies
  • Perfect for naturalized areas and meadow gardens
  • Adds authentic regional character to native plant collections

Growing Arrow Thelypody Successfully

The good news is that arrow thelypody isn’t particularly fussy – after all, it’s survived in some pretty tough western landscapes for millennia. Here’s how to keep it happy in your garden:

Growing Conditions: This plant prefers full sun to partial shade and can handle a range of soil types. It’s particularly tolerant of alkaline soils, which is great news for western gardeners dealing with high-pH conditions. The key is providing adequate moisture, especially during the growing season.

Climate Needs: Hardy in USDA zones 3-7, arrow thelypody is well-suited to the temperature extremes of the mountain west. It can handle cold winters and hot summers like a champ.

Planting Tips: Since this is a biennial or perennial, give it space to establish and potentially self-seed. Plant in spring after the last frost, and don’t worry if it doesn’t flower the first year – good things come to those who wait!

The Perfect Garden Fit

Arrow thelypody isn’t meant for formal flower borders or high-maintenance garden beds. Instead, it shines in:

  • Native plant gardens focused on regional species
  • Meadow or prairie-style plantings
  • Restoration projects
  • Wildlife gardens designed to support pollinators
  • Naturalized areas where you want authentic western character

Supporting Your Local Ecosystem

While arrow thelypody might seem humble, it plays an important role in supporting western ecosystems. Its flowers provide nectar for small pollinators, and as a native plant, it’s part of the complex web of relationships that keep our local environments healthy. When you plant arrow thelypody, you’re not just adding a plant to your garden – you’re helping maintain the biodiversity that makes western landscapes special.

So, should you plant arrow thelypody? If you’re looking for a low-maintenance native that adds authentic western character to naturalized areas, the answer is yes. Just don’t expect it to be the star of your flower garden – think of it more as a reliable supporting actor that helps make the whole production better.

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 work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags 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. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Arid West

FACW

Facultative Wetland - Plants with this status usually occurs in wetlands but may occur in non-wetlands

Great Plains

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Western Mountains, Valleys, and Coast

FACW

Facultative Wetland - Plants with this status usually occurs in wetlands but may occur in non-wetlands

Arrow Thelypody

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Capparales

Family

Brassicaceae Burnett - Mustard family

Genus

Thelypodium Endl. - thelypody

Species

Thelypodium sagittatum (Nutt. ex Torr. & A. Gray) Endl. ex Walp. - arrow thelypody

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