Giant Trillium (Trillium albidum) Bunchflower Family (Melanthiaceae)

It grows in moist to wet woods, along streambanks, and in shaded open areas at low to middle elevations. Out at the arboretum, you will find this plant growing along the riverbank trail, the creek trail, on the shady hillside forest, and in the wetlands.

Flower

There are three white petals and three green, lance-shaped sepals in the center that sit on top of the base of the leaflike bracts. There are six stamens and three styles. I took a photo of the flower up close. I stamens are long, narrow, rounded at the top, and resemble small flat paddles. They look like they have yellow pollen that runs along the edge. The styles in the middle twist and curl into these interesting shapes. This a beautiful, showy flower that emerges in early spring. Curiously, I have yet to see what pollinates this flower. I am usually out at the arboretum during the day, so maybe a moth or beetle visits the flower at night. Even though the spring can be cool and damp in the Northwest, there are always sunny, warm days sprinkled in there to wake up pollinators.

Leaves

The huge leaf-like structures on this plant are bracts. The three bracts grow in a whorl are attached at the base at the end of a stalk. The bracts are usually mottled with green or brown spots. The bract shape is broadly ovate that comes to a point at the end.

Seeds

The seed pod forms into a capsule that turns a dark, rich purple-black. The seeds have a lipid-rich seed appendage known as an elaiosome which is attractive to ants. Ants will collect the seeds and either store seeds in the nest or remove the elaiosome and then discard the seeds which help disperse them. In the seed capsules that I have observed thus far, the ants tear open the capsule, remove the elaiosome from the seed, and leave the seed behind.

References

Burke Herbarium Image Collection. https://biology.burke.washington.edu/herbarium/imagecollection/taxon.php?Taxon=Trillium%20albidum. Accessed 13 July 2022.

Giant White Wakerobin, Trillium Albidum. https://calscape.org/Trillium-albidum-(). Accessed 13 July 2022.

“Trillium Albidum.” Sevenoaks Native Nursery, https://www.sevenoaksnativenursery.com/native-plants/perennials-and-bulbs/trillium-albidum/. Accessed 13 July 2022.

Quick Reference:

Height: 1 - 2' feet.
Leaves: Whorl of 3 usually mottled bracts.
Flowers: 3 white petals, 3 green sepals; directly on top of bracts.
Habitat: Moist to wet areas along streambanks or shaded open areas.

Journal Location:
Mt. Pisgah Arboretum, Eugene, OR
Mt. Pisgah Arboretum Website
Mt. Pisgah Arboretum Plant List