Urban Arboretum: Bio-retention Zone

November 02, 2022

Scroll through the gallery to learn about these unique plants. Click on the header image to return to the main page.

Bioretention Zone species
The bio-retention planters are located in the plaza off 8th Avenue and Blanchard Street.
Bioretention planters
Cornus sericea
This species in these planter boxes is Cornus sericea, commonly called red-osier dogwood. Sericea comes from the Latin word for "silky," which refers to the texture of the species' leaves. It is native throughout Northern and Western North America. In nature, you are likely to find it growing in wetlands, where damp soil is in abundance.
Bioretention Zone species
During the fruiting months, Cornus sericea produces globose white berries. When ripe, they will turn light purple and resemble a pale blueberry.
Species at Terraced Swale
Nyssa sylvatica
Commonly known as a black tupelo or black gum. This specific species is also called the green gable. If you're on campus in the spring or summer, look for dark green, glossy leaves. In the fall, you're in luck. This tree turns a vibrant crimson before shedding its leaves for the colder months.
Species at the Terraced Swale
Blechnum spicant
Also known as the deer fern. This evergreen fern is a unique as it has two different types of leaves, or 'fronds'. The evergreen sterile fronds are stiff, leathery and dark green, forming a rosette shape at its base. As the season progresses, these fronds may stretch to lie on the ground. The second are the fertile fronds, which grow in an upright position at the center of the rosette. They look similar to the sterile fronds but are taller, thinner, and spread out more widely. The most distinct difference is that fertile fronds will turn brown and fall from the plant by the end of the warmer months.
Species at the Terraced Swale
Iris macrosiphon
Also called the bowltube iris. This flowering plant is native to the Cascade Foothills, north and central Sierra Nevada Foothills, and San Francisco Bay Area, where you might see it growing in sunny grasslands, meadows, and open woodlands.