Pseudotrillium spp.

brook wakerobin

Melanthiaceae

Pacific Northwest (Oregon and California)

Attracts Pollinators Container Friendly

Native to North America

SunPart Shade – Full Shade

WaterMedium

HardinessZones 5–8

Overview

Pseudotrillium spp. is a genus in the family Melanthiaceae containing a single species, P. rivale, the brook wakerobin, once classified within Trillium spp.. It is a low, rhizomatous, spring-flowering woodland perennial growing 4-12 inches (10-30 cm) tall. Three broadly oval, stalked leaves are carried in a whorl atop the stem, each 1.5-3 inches (4-8 cm) long and marked with faint mottling when young. Unlike true Trillium spp., the single flower is held on a slender stalk (pedicel) that lifts it above the leaves. Each flower has three white to pale pink petals 0.5-1 inch (12-25 mm) long, often spotted or streaked with maroon toward the base. Flowering occurs in early spring, after which the plant sets a berry-like capsule and dies back to the rhizome by summer, behaving as a spring ephemeral. The genus is restricted to a small area of the Pacific Northwest and grows along shaded, moist streambanks. It is slow to establish and slow to recover from disturbance once settled.

Native Range

Pseudotrillium rivale is endemic to a small region of the Klamath-Siskiyou Mountains in southwestern Oregon and northwestern California. It grows on shaded, rocky streambanks and seepage slopes, often over serpentine soils, in moist coniferous and mixed woodland.

Suggested Uses

Grown in shaded rock gardens, woodland borders, and alpine or trough plantings by collectors of Trillium spp. relatives. Its small size suits the front of moist, shaded beds. It pairs with ferns, hellebores, and other spring woodland plants.

How to Identify

Recognize Pseudotrillium spp. by its whorl of three stalked, oval leaves and its single white to pale pink flower held on a short stalk above the foliage, rather than sitting directly on the leaves as in most Trillium spp.. The petals are usually spotted with maroon near the base. The whole plant rarely exceeds 12 inches (30 cm).

Appearance

Size & Dimensions

Height4" - 1'

Width/Spread6" - 1'

Reaches mature size in approximately 4 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring

Flowering occurs in early spring, often March to April, with each plant producing a single, long-lasting flower. Bloom appears soon after the foliage emerges. By early summer the plant goes dormant.

Detailed Descriptions

Flower Description

white to pale pink with maroon spots

Foliage Description

green with faint mottling

Growing Conditions

Sun Requirements

SunPartial Shade SunFull Shade

Requires 2-5 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam rocky

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3-5 years

Care & Maintenance

Care Guide

Grow Pseudotrillium spp. in part to full shade in humus-rich, gritty, consistently moist but well-drained soil. The genus suits cool woodland and shaded rock gardens and tolerates serpentine and slightly acidic to neutral soils. Keep the root zone moist during spring growth, allowing it to dry somewhat during summer dormancy. A mulch of leaf mold conserves moisture and feeds the rhizome. Plants are slow-growing and may take several years to settle and flower freely, so they are left undisturbed once planted. Slugs and snails can damage the emerging shoots.

Pruning

No pruning is required for Pseudotrillium spp.. Spent foliage is left to die back naturally, as it feeds the rhizome for the following season. Damaged or yellowing leaves can be removed once dormancy begins.

Container Growing

✓ Suitable for container growing

Minimum container size: 2 gallons

⚠️ Toxicity Warning

Unknown

Perennials