Flora « Oregon Sea Grant Sustainable Tourism

Many plants sharing our gardens are not natives but imports from other lands. At the time, introducing the species probably seemed like a good idea, that is until it turns invasive and deadly.

Scotch Broom is a perennial shrub with lovely yellow pea-like flowers, dark green stems, and evil on its mind. OK I made up the evil part, but the more you know about Scotch Broom the more you might agree.

History

Scotch Broom was introduced in the US in the early 1800s.

History indicates that broom was imported as domestic sheep fodder. But, broom may have been imported for its wide variety of medical and utility functions.

Medical ailments treated included (Note: This weed is poisonous. Modern medicines provide safer alternatives):

Heart problems	Hemophilia	Rheumatism	Gout
Jaundice	Kidney stones	Respiratory conditions	Snake Bite
Sore muscles	Infections	Purgative	Emetic

Utility functions included hair rinse, leather tanning, sweeping brooms, thatched roofs, rope, beer flavoring, yellow dye, and a substitute for hops, capers, and coffee. In addition, Scotch Broom roots host nitrogen-fixing bacteria which help the plant colonize nutrient-poor soils.

It is native to much of Europe and Africa where natural predators for the plant evolved.

In the early 1900’s, broom was planted to prevent soil erosion along Pacific Coast highways. It probably seemed like a great idea at the time.

It didn’t take very long for Scotch broom to become an international superstar pest. Today, broom is considered a pest throughout most of its range.

More than just one

Does it seem like the Scotch broom blooms more than once a year? Well, it does, kinda. There is more than one type of broom and more than one type lives on the Oregon Coast.

The ranges for Scotch, Spanish, French, and Portuguese broom overlap. You may notice different bloom seasons, lighter color flowers, height differences, and more. All have a nice yellowish bloom similar to a pea.

Scotch broom and Gorse are sometimes confused (Gorse is very stickery). They both grows in similar conditions, and cause similar problems, but are different species.

Pest Status

This plant has earned its weed status well by aggressively invading many areas. Once in place it is very difficult to get rid of and control. What makes it so bad?

Broom regenerates quickly, forming dense stands. These stands are unpalatable and somewhat poisonous to wildlife. They will become so dense that even quail cannot live there.

These thick dense stands will also prevent normal reforestation and regeneration processes and drive many native species out by shading, increasing soil acidity, and toxicity.

Broom increases fire hazard frequency and intensity. It is one of the most flammable plants there is and poses enormous threat to communities.

It creates a high fire hazard frequency and intensity. Even green, the shrubs will cause a fire to erupt. The broom is one of the most flammable plants there is and poses an enormous threat to our community’s fire safety.

Seeds

The plant is a prolific seeder and can release 20,000 or more seeds per plant every year. Seeds stock pile over time until destroyed or germinated. Seed remain viable in the soil for decades and any disturbance can cause the seed to germinate.

Seeds will germinate after a ‘cooler’ fire (depending on the temperature of the fire). Hot fires can destroy the seeds.

It is hard to get rid of….

The only way to control this plant is through repetitive and ongoing treatments. Treatments include manual removal, chemicals, burning (hot), shading through planting, and some biological options (Bruhidius villosus, exapion fascirostre, and Leucoptera spartifoliella).

Once established, the plant is very drought tolerant. This tolerance makes herbicides less effective during certain times of the year.

So Expensive

Scotch Broom causes substantial timber revenue losses and costs a lot to control – somewhere over $40 million a year in Oregon alone.

REFERENCES:
–OSU Extension Service (https://extension.oregonstate.edu/news/scotch-broom-beautiful-noxious)
–WebMD (https://www.webmd.com/vitamins/ai/ingredientmono-375/scotch-broom)
–King County, Scotch Broom (https://bit.ly/2X7XvAh)
–Scotch Broom (https://www.invasivespeciesinfo.gov/profile/scotch-broom)
–The News Review, Ask a Master Gardener… (https://bit.ly/2X9v4Sq)
–USDA Fire Effects Information System (FEIS) (https://bit.ly/3gar3ol)
–Wikipedia, Cytisus scoparius (https://en.wikipedia.org/wiki/Cytisus_scoparius)
–Weeds, Working Lands (https://bit.ly/30TRtUO)

‘Sacred bark’

Leaves and berries of the Cascara tree (courtesy Oregon State University, landscape)

Cascara is a medium-sized deciduous tree or large shrub that can reach 33-feet tall.

Spanish conquerors found several native people using the bark in the 1600s. The conquerors named the mottled gray bark “Sacred bark.”

Processed bark became famous in the 1800s. It was exported to the European markets.

As one might have guessed, the Pacific Northwest native tree populations declined through overharvesting.

Rising Star

Who would have thought that a local bark could become famous?

The commercial product was called ‘Cascara sagrada’ and it was used in more than 20 percent of the U.S. products in the late 1990’s. The industry at that time had an estimated value of $400 million.

In May 2002, the U.S. Food and Drug Administration banned the use of this tree in over-the-counter drug products and found the use potentially carcinogenic.

Cascara flowers (courtesy of Oregon State University, Landscape)

Bark?

The outer bark has light splotching (sometimes from lichens). The inner bark is smooth and yellowish. Exposed inner bark will oxidize and turn brown.

Fresh cut bark is intensely bitter and will overpower the taste buds—for hours. Fresh cut, dried bark will cause vomiting and violent diarrhea.

Fruit

The sickly, sweet fruit can be eaten cooked or raw. The berries are deep purple or black with yellow pulp. The berries usually contain two or three hard, smooth seeds.

In the past, the food industry used cascara as a flavoring agent for liquors, soft drinks, ice cream, and baked goods.

NOTE: The fruit and honey both have a laxative effect.

When to Collect

Bark collected in the spring or early summer can be easily peeled off the stem. Bark will be aged and dried for at least a year before use.

Use

Cascara tree bark is a strong laxative that should be used carefully.

It can induce labor in pregnant women and transfer active compounds to nursing infants.

There are several precautions about this bark and warnings that it may be carcinogenic.

Where Found

This tree is native to northern California up to British Columbia and from the Pacific Coast east into Montana. Leaves are oval up to 6-inches long with fine edge serrations. Small, green flowers develop into blue-black fruits.

Cascara plant grow near streams in mixed forests. Check under big leaf maple trees–they are often an understory there.

Safe Uses

The fall yellow leaf color is pleasant (color varies based on light) and branching is interesting. Cascara does not adapt well to urban settings and is better in a woodland park or garden.

Cascara is a nice ornamental that can help prevent soil erosion and provide wildlife food and habitat. The fruit is a favorite of the Pileated woodpecker. Bears, raccoons, deer, and other wildlife also consumed the berries.

REFERENCE:
–Oregon State landscape plants (https://landscapeplants.oregonstate.edu/plants/rhamnus-purshiana and https://landscapeplants.oregonstate.edu/plants/frangula-purshiana)
–Wikipedia, Rhamnus purshiana (https://en.wikipedia.org/wiki/Rhamnus_purshiana)
–Native Plants of the Pacific Northwest (http://nativeplantspnw.com/cascara-frangula-purshiana/)
–Trees & Shrubs for Pacific Northwest Gardens, Grant & Grant

Neither a grape or a holly be…
This evergreen is not a tree.
The spike and point to clusters yellow,
Makes the fruit a favorite fellow.

Oregon grape became our State Flower in 1899. Choosing a favorite from so many beauties must have been difficult.

Oregon Grape flower and leaves (image courtesy of Oregon State University, Landscape)

State flowers provide a way to showcase abundance, beauty, historical significance, feelings, and economic prowess. Oregon grape was chosen to represent beauty and abundance.

Why Oregon Grape?

The common plant name suggests that this plant is a grape. It is not.

Oregon Grape is a woody evergreen shrub under the Berberis Barberry family. Barberry shrubs are common in many Pacific Northwest landscapes.

Where Found?

Oregon Grape grows in Southeast Alaska, east into Alberta, Canada, and south into central New Mexico. It often grows in Douglas-fir forests common in the Pacific Northwest.

Clusters of bright yellow flowers makes this plant easy to identify in the early spring. In the fall, the plant produces a crop of small, purple-ish-black grape-shaped fruit. The fruit is bitter, but edible.

Oregon Grape flower close up (image courtesy of Oregon State University, Landscape)

Not a Holly

The dark green, glossy holly-like leaflets have sharp spines and can reach 12-inches in length.

It is not closely related to a holly. Like a holly, this plant will tolerate poor soils, resist summer drought, and create minimal leaf litter. It rarely grows over four feet tall.

Shiny leaves are usually a sign that a plant will resist wilting making them attractive to florists. Depending on the variety (and there are several), the leaf color may shift in the fall to more of a purple-ish tint.

Who Loves Ya?

Birds love the berries, along with the bees and butterflies. Berries can be used to make juice, jelly, jam, and wine. Note: The berries are quite tart and have large seeds. Berries are best eaten after the first frost.

Indigenous people used the inner bark and roots to make yellow dye; berries make a purple.

Medical

Medicines for stomach ailments and fighting bacterial/fungal infections have been made from rhizomes. There is even documentation show it might help with psoriasis.

Other Uses

Oregon Grape is deer resistant. The sharp spiny leaves make formidable natural barriers.

The plant does not require regular fertilization. A bit of compost over the root zone will help it retain moisture and reduce weeds).

The Oregon Grape provided much utility for pioneering families and indigenous peoples in our area.

REFERENCE:
–World Atlas, What is the State Flower of Oregon? (https://www.worldatlas.com/articles/what-is-the-state-flower-of-oregon.html)
–Oregon State University, Landscape Plants (https://landscapeplants.oregonstate.edu/plants/mahonia-aquifolium)
–Web MD (https://www.webmd.com/vitamins/ai/ingredientmono-493/oregon-grape)
–Wikipedia, Oregon Grape (https://en.wikipedia.org/wiki/Mahonia_aquifolium and Berberis_aquifolium)
–Britannica Encyclopedia, Oregon Grape (https://www.britannica.com/plant/Oregon-grape)
–Oregon Grape-Holly Care (https://www.gardeningknowhow.com/ornamental/shrubs/mahonia/grape-holly-plant-care.htm)

Oregon Sea Grant Sustainable Tourism

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Category Archives: Flora

Scotch Broom (Cytisus scoparius)