Pacific trillium is one of the first big wildflowers of spring in moist forests at low and middle elevations around Mt. Hood. Almost everything about it comes in threes: a single whorl of three broad leaves, three green sepals, and three white petals on a short stalk above the leaves. As a flower ages its petals slowly blush pink, then rose or purple, so one patch can show several shades at once.
The plant grows from a short, thick underground stem, and it takes its time. Its seeds need two winters and a summer before roots and then leaves appear, and trilliums in general have been recorded taking anywhere from 4 to 20 years to bloom for the first time. Each seed carries a small, oily packet that ants love. Ants haul the seeds home, eat the packet and leave the seed in their tunnels, usually only about a meter from the parent plant.
Look for it in shady, damp woods from early spring into early summer, often where the ground stays soggy in spring. Because a trillium needs so many years to reach flowering size, it is worth leaving the blooms for the next hiker.
How to identify it
A single whorl of three broad, pointed, plain green leaves sits at the top of a bare stem roughly 4 to 12 inches tall. One flower rises above the leaves on its own short stalk, with three narrow green sepals and three wider white petals. The petals fade to pink, rose or purple as the flower ages.
Look-alikes
Other trilliums in the region have flowers that sit directly on the leaves, and some have mottled leaves; Pacific trillium's flower always stands on a short stalk and its leaves are plain green. Bride's bonnet also carries one white flower, but it has six petal-like parts and two or three leaves at the base of the stem.
Habitat
Open to dense moist forest at low and middle elevations, often in spots that stay boggy in spring. Its range runs from British Columbia to California.
Sightings in the forest
1,151 research-grade sightings in Mt. Hood National Forest on iNaturalist, most recently on September 26, 2026. See them on iNaturalist →