Although introductions are probably not necessary, this is Trillium ovatum, an unmistakable and endearing plant that softly lights up the vernal understory of moist coniferous and mixed forests from southern British Columbia, south to California, east to Idaho, Montana and small parts of Wyoming and Colorado, and north to southwestern Alberta. It’s part of a large genus, with about 50 other members that are native to temperate areas of North America and Asia.
Trillium ovatum’s common names are “western trillium” and “wake robin,” the latter due to its unofficial designation as harbinger of spring. Trillium comes from modern Latin, reportedly an alteration of the Swedish trilling, meaning “triplet,” which refers to its three leaves and three petals. Ovatum is derived from the Latin ovum meaning “egg-shaped,” which describes the leaf outline.
How it grows
A perennial that grows from rhizomes, it technically produces no true leaves or stems above ground; the stems are considered an extension of the horizontal rhizome. The part of the plant that we notice most is an upright flowering scape (stalk), and the leaf-like structures are bracts, but most people call them leaves because they photosynthesize. The smaller leaf-like structures just under the flower are sepals.
Trillium species are divided into two types: Pedicellate (those with flowers that have a short stalk called a peduncle) and sessile (those with flowers attached directly to the bracts). The flowers have six stamens and three stigmas. Trillium plants are very long lived and can take as long as 10 years to flower from seed. As the flowers age and following pollination, the white flowers change to pink or even burgundy. Trillium are known as spring ephemerals; as summer proceeds, they go into dormancy and mostly disappear from our view (although those that are well established or receive adequate summer water usually maintain their greenery above ground following the flowering period).
Wildlife value
Pollination happens thanks to native bumble bees, moths, and beetles. The resulting fruit is fleshy and berrylike; the seeds evolved to have fleshy elaiosomes whose nutritious proteins and fats attract muscular ants who carry the seeds back home to feed their young. After the food is consumed, they toss the still viable seed and, voila! Seed dispersal accomplished.
Try it at home
Although trillium plants are quintessential forest denizens, they usually do well in shaded to partly shaded, moist woodland gardens, or even just moist (but well drained) areas on the north or east side of houses, provided that the soil is rich in organic matter and slightly acidic (pH 5.0 to 6.5). Leafy and woody debris is very important in the forest, and should be allowed to accumulate and decompose on the soil at home as well, since fallen leaves, bark, twigs, cones, and branches slow moisture loss and provide habitat as well as nutrients. If your soil is poor and lacking in organic matter, or if the top soil is shallow, add some compost as mulch (leaf compost is good) right after planting and allow whole leaves to continually accumulate on top to eventually create more humus.
Trillium can withstand minor droughts, but occasional summer water will help keep them going until winter rains begin. Recent transplants should definitely be kept slightly moist during the first couple of summers.
The plants you buy will likely be small, but in the right conditions and over many years they will slowly spread from rhizomes to a clump as wide as two feet. Grow them as nature would: In drifts with individual plants roughly several feet apart. Although I haven’t quite gotten around to growing them from seed, sources say that seed should be collected when capsules begin to open in midsummer. Sow them twice as deep as the seed’s diameter (or slightly deeper) in deep containers with coarse growing medium. Leave them outdoors in a shaded spot to mimic natural conditions. More detailed info on propagation here.
Some PNW associates to grow them with include Douglas-fir, western redcedar, western hemlock, Pacific rhododendron, vine maple, salal, sword fern, maidenhair fern, deer fern, vanilla leaf, oxalis, western wild ginger, and stream violet.
Other Pacific Northwest trillium
Trillium albidum occurs in most parts of western Oregon, as well as Thurston, Pierce and Lewis counties in Washington, and much of northern California. Trillium parviflorum grows naturally in southwestern Washington and northwestern 
Oregon. Trillium rivale occurs only in southwestern Oregon and the northernmost counties of California. Trillium kurabayashii (pictured, right) is naturally found only in Oregon’s Curry County, as well as Del Norte and Humboldt counties of California.
Only buy natives from reputable nurseries and never dig plants from the wild. And it’s true what they say about never picking the flowers—doing so may eliminate the only chance the leaf-like bracts have for photosynthesis, and cause the plant to weaken or possibly even die.
Does this trillium grow naturally only in wetland or near wetland areas?
Thank you.
It grows mainly in dense, moist forests at low to mid elevations, sometimes where the soil is very wet in springtime. Its wetland status is “FACU (Facultative Upland – Nonhydrophyte. Usually occurs in non-wetlands, but may occur in wetlands.)”
I spent years in the Pacific Northwest. It was magical walking through the woods! I’m back in my home state of Maine. It’s lovely here, but doesn’t compare with the Great Northwest.
Its not common to find truly informative pages on any native wildlife in the NW, with the how-to on growing them your self. I’m impressed and thank you very much!
Thank you for your kind words, Michael! If you live west of the Cascades, please check out my book if you haven’t already. (It’s on backorder at this time almost everywhere but I could mail you a signed copy if you’re interested in buying one). Take care.
My grandmother, Rosamund Wakeman Hess, was credited with discovery of a Trillium only found in Curry County, Oregon. This would have been late 1970s. We have lost track of name and wondered if you could be any help. She lived in Wedderburn at the time. DAR also recognized her efforts. Any help would be fabulous.
As I wrote in the post, “Trillium kurabayashii … is naturally found only in Oregon’s Curry County, as well as Del Norte and Humboldt counties of California.”