Western Trillium

May 21, 2023June 14, 2023
Flora and Fauna, Native to BC
by dhir

Last updated June 14, 2023. All photos by the author.

Also known as Pacific trillium and western white trillium, Trillium ovatum can be found in moist forest in southern British Columbia and the Pacific northwest of the United States. This USDA page has good information on western trillium.

The following photos were taken in late April two years apart in Burnaby. Initially bright white, trillium flowers quickly decay to pink then dark purple as the pollinated flower starts making the fruit. I read that trillium flowers do not produce nectar, only nutritious pollen sought after by various insects. Trillium is a long lived perennial (up to 25 years!) that is easy to identify due to it’s relatively large leaves (compared to the other woodland flowering plants it normally grows near) and distinctive 3-petaled flower.

Found in singles or clumps, western trillium are decreasing in the wild and are protected by law. Do not harvest or disturb these plants!

In the centre of this flower you can see the fruit starting to form.

Seen from above, western trillium is easy to identify with its three large symmetrical leaves. Below the plant are false lily-of-the-valley and a deciduous fern.

Surrounded by false lily-of-the-valley and various ferns, the flowering western trillium stands out brightly in a sea of green.

If you are lucky you may come across a clump of western trillium rather than just a single flower.

From the side you can see how tall the stalk is compared to the size of the flower.

This week I went for a walk and found the following western trillium plant. Now that I am constantly looking for flowers, I often wonder what the fruit looks like, and western trillium is no exception. I plan to go back in a few weeks and see what progress has occurred.

June 14, 2023. The pollinated flower has become a green fruit. Notice the dried out petals curling downwards.

From a bit farther away, western trillium is harder to spot when it’s not in bloom, as its green blends in with the salmonberry and other herbaceous plants around it.

From directly above, you can see the three large leaves and smaller sepals surrounding the maturing fruit in mid-June.

Western trillium can grow up to 50 cm (20 inches) tall. This is a slow-maturing plant, taking many years of growth before it will invest energy in flowering. I read that it could take 7 years to go from seed to flowering plant! This interesting plant spreads by rhizome (underground stem) and by seed. If you pay attention to where you find these flowering plants, you should notice that they are always in the shade. Add to the limited sunlight the fact that they survive with only 3 leaves above ground for part of the year and you come to understand why they are so precious.

Indigenous people used the fleshy rhizomes for medicinal purposes.

So head outside this week, or any week in spring, summer, or early fall, and look carefully for this beautiful, three-leaved, native flowering plant.

BOOKS I READ:

“***.” Gardening with Native Plants of the Pacific Northwest Third Edition, by Arthur R. Kruckeberg and Linda Chalker-Scott, Greystone Books, 2019, pp. ****

“Western Trillium” The Flora and Fauna of Coastal British Columbia and the Pacific Northwest, by Collin Varner, Heritage House Publishing Company Ltd., 2018, p. 63.