North America Native Plant

Streambank Wild Hollyhock

Botanical name: Iliamna rivularis var. rivularis

USDA symbol: ILRIR

Life cycle: perennial

Habit: subshrub

Native status: Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Iliamna acerifolia (Nutt. ex Torr. & A. Gray) Greene (ILAC)  âš˜  Iliamna corei Sherff (ILCO4)  âš˜  Iliamna remota Greene (ILRE)  âš˜  Phymosia remota (Greene) Britton (PHRE3)  âš˜  Sphaeralcea rivularis (Douglas ex Hook.) Torr. (SPRI4)   

Streambank Wild Hollyhock: A Rare Native Beauty Worth Protecting If you’re looking for a show-stopping native perennial that’ll make your neighbors do a double-take, let me introduce you to the streambank wild hollyhock (Iliamna rivularis var. rivularis). This impressive wildflower is like the tall, elegant cousin of your garden-variety hollyhock ...

Rare plant alert!

Region: United States

Status: S1Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ 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) ⚘ 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) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Region: United States

Region: United States

Streambank Wild Hollyhock: A Rare Native Beauty Worth Protecting

If you’re looking for a show-stopping native perennial that’ll make your neighbors do a double-take, let me introduce you to the streambank wild hollyhock (Iliamna rivularis var. rivularis). This impressive wildflower is like the tall, elegant cousin of your garden-variety hollyhock – but with a conservation story that makes it extra special.

What Makes Streambank Wild Hollyhock Special?

This native North American perennial is a real head-turner. Imagine a plant that can tower 3-8 feet tall, adorned with gorgeous pink to rose-colored flowers that look like they belong in a cottage garden, but with distinctly maple-shaped leaves that give away its wild heritage. The flowers are generous in size and absolutely magnetic to pollinators – bees, butterflies, and hummingbirds can’t resist them.

As a forb herb, streambank wild hollyhock lacks the woody stems of shrubs but makes up for it with its herbaceous vigor and perennial staying power. It’s the kind of plant that anchors a native garden with both height and beauty.

Where Does It Call Home?

This remarkable plant is native to both Canada and the lower 48 United States, with populations scattered across Alberta, British Columbia, Colorado, Idaho, Illinois, Indiana, Montana, Nevada, Oregon, Utah, Virginia, Washington, and Wyoming. It’s quite the traveler, but don’t let that widespread distribution fool you – this plant is actually quite rare.

A Conservation Concern We Need to Address

Here’s where things get serious, fellow gardeners. Streambank wild hollyhock has a Global Conservation Status of S1, meaning it’s critically imperiled. In some areas, like Peter’s Mountain, it’s actually listed as Endangered. With typically fewer than 1,000 individuals remaining in most locations, this is a plant that desperately needs our help.

If you’re considering adding this beauty to your garden, please – and I cannot stress this enough – only source it from reputable native plant nurseries that can guarantee responsibly collected or ethically propagated material. Never collect from wild populations.

Perfect Spots for Streambank Wild Hollyhock

As its name suggests, this plant loves life near water. In the wild, you’ll find it along streambanks and in moist meadows. For your garden, think:

  • Rain gardens and bioswales
  • Naturalized areas with consistent moisture
  • Back borders of native plant gardens
  • Pond or water feature margins
  • Any spot that stays reliably moist but not waterlogged

Its wetland status is Facultative, meaning it’s equally happy in wet and moderately dry conditions – though it definitely prefers the moister side of life.

Growing Your Streambank Wild Hollyhock

If you’re lucky enough to source some responsibly grown streambank wild hollyhock, here’s how to keep it happy:

Location: Choose a spot with full sun to partial shade. This plant is adaptable but thrives with morning sun and some afternoon protection in hotter climates.

Soil: Rich, organic, consistently moist soil is ideal. Think of a streambank – fertile, well-draining but never completely dry.

Hardiness: Hardy in USDA zones 3-7, so it can handle some serious cold but struggles in extreme heat.

Care: Once established, it’s relatively low-maintenance. Keep soil consistently moist, especially during dry spells. A thick layer of organic mulch helps retain moisture and suppress weeds.

Why Pollinators (and You) Will Love It

Those showy pink flowers aren’t just pretty faces – they’re pollinator magnets. Bees adore the abundant pollen and nectar, butterflies appreciate the landing platform-like petals, and hummingbirds are drawn to the rich nectar. By growing streambank wild hollyhock, you’re creating a vital pit stop in the pollinator highway.

The Bottom Line

Streambank wild hollyhock is absolutely worth growing – but only if you can source it responsibly. This is a plant where conservation gardening really matters. By choosing to grow this rare native, you’re not just adding beauty to your landscape; you’re participating in conservation efforts that could help ensure future generations get to enjoy this remarkable plant.

Remember: beautiful gardens and conservation can go hand in hand. Sometimes the most rewarding plants to grow are the ones that need our help the most.

Streambank Wild Hollyhock

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

Malvales

Family

Malvaceae Juss. - Mallow family

Genus

Iliamna Greene - wild hollyhock

Species

Iliamna rivularis (Douglas ex Hook.) Greene - streambank wild hollyhock

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