A Tale of Three Ribes

M and I were camped in a clearcut in Loomis Forest (Okonogan county) in June, and found three different Ribes (R. cereum, R. lacustre, and R. viscosissimum) in full bloom within a ten foot radius. Despite being in members of the same genus, the flowers of these three species look very different. R. lacustre is bowl-shaped and brown; R. cereum is tubular and pink; R. viscosissimum is also pink, but has a showy ring of flared sepals around the tube.
My first thought was that these three similar shrubs must have different pollinators. How else to explain their floral diversity? The idea that pollinators drive the evolution of flower structure (The Grant-Stebbins model) is neither new nor edgy.
Just like with Darwin’s orchid, whose pollinating moth was not discovered until years after Mr. Darwin predicted its existence, there must be a creature that prefers each of these shapes, right?
North American Ribes are moneceous, with perfect flowers. Research on domesticated Ribes has shown that most Ribes are bee-pollinated; exclusion of pollinators significantly reduces yield.www.pollinator.ca/canpolin/gooseberries.html Though the stamens and anthers are positioned to discourage self pollination, it is known to occur. However, self-pollinated fruits often drop before ripening.
A study in California (http://humboldt-dspace.calstate.edu/handle/2148/1279) found that despite floral differences, the 14 species tested were all visited mostly by bees, though gnats, beetles and hummingbirds also stopped by. “Visitor assemblages varied as much between sites for individual species as they did between different species.”
Hybrid Ribes are unusual in the wild, though they are used in agriculture. An experiment In Latvia successfully crossed our Ribes sanguineum with their commercial black current (R. nigrum). Hybrids successfully bore fruit, and exhibited increased fungal resistance.
So, what have I learned from looking at these three shrubs growing and flowering together? They share at least some pollinators. Something other than pollinators is keeping them distinct. I’m not the first person to ask these questions. Maybe searches at a mollecular level will discover the answers. Maybe they will just raise more questions.

Oxalis oregana

Wood sorrel (also called Oregon sorrel or redwood sorrel) is another Pacific coast native, a plant of the coast ranges from central California through Washington. It is common from the wet side of the Olympic Peninsula south. The WTU Herbarium lists it as occurring in King County, but I could only find one non-garden-origin specimen in the database, from a Mercer Island address.
Neither WTU herbarium nor the USDA Plants database show it as occurring on the mainland North of King County. It is listed as a “species of special concern” in British Columbia.
The name Oxalis comes from the Latin word for sour. The plant contains oxalic acid, which can be toxic in large quantities. It can combine with calcium or other metals in the body to form kidney stones. Oxalic acid is also the component of rhubarb leaves that makes them toxic.
The US EPA classes oxalic acid as a pesticide, mostly because it is used as a disinfectant in some bathroom cleansers and swimming pool treatment systems. Exposure to concentrated oxalic acid can cause skin irritation and eye damage, but it degrades quickly, and is not considered a threat to wildlife.
In Ethnobotany of Western Washington, Erna Gunther states that the Cowlitz and Makah tribes use the juice of Oxalis as an eye wash. Other tribal uses are as a wash to counteract skin irritations and rheumatism, and as a trail snack.
In the garden, Oxalis oregana is an appealing groundcover with shamrock leaves and pink-tinged white flowers. It tolerates deep shade, exhibiting nyctinasty (folding its leaves in response) when subjected to bright sunlight. It is also rhizomatous, and will spread to cover whatever area it can. (This is a beautiful thing if you want to fill in bare ground between the sword ferns under your rhododendrons; not so much if you have planted it with delicates in your formal border.)
So. The sour leaves and flowers of O.oregana make a wonderful trailside snack or addition to a salad; just don’t overdo it. Plant it somewhere where you won’t be battling its exuberant nature. And, if you find it growing wild (not as a garden escapee) north of Olympia, please tell me!

Oemlaria Cerasiformis

A good plant to think of in January. Also, the first Plant of the Month column I ever wrote.

Around the time this newsletter comes out, some of you will probably be looking for the first signs of spring. A good place to start is the shrub Oemlaria cerasiformis, also called osoberry or Indian plum. Native to the west slope of the Cascades from BC to California, it is one of the earliest low altitude spring bloomers. Here in the Puget Sound lowlands, it can occasionally be found in flower as early as late January. O. cerasiformis is dioeceous, with male plants being more common than females, and also sporting more flowers and a longer blooming time. Male and female flowers are superficially similar, but if you look inside (use a hand lens), the flower will either have developed stamens or ovaries. You can also “cheat” by looking for the remaining stems from last year’s fruit on the female plants.
In the landscape, osoberry tends to blend in with the other shrubs in the forest edge or riparian area, an inconspicuous wall of green when it is not dressed in sprays of delicate white flowers. In my yard, at least, the leaves start to yellow and fall by late August, making it both early to bed and early to rise.
The fruits are drupes, like plums or cherries, (also members of the rose family), and ripen as early as May or June, first blushing orange, then red, then nearly black when they are ripe. They are edible, if you can get to them before the birds and critters do – everyone from cedar waxwings and grosbeaks to racoons and coyotes enjoys an osoberry. Try to find one from a sunny branch. It will have a higher sugar content. If you can collect enough, they make an excellent jam.
So, put on your boots and raingear, and take yourself for a walk along a lowland forest edge, looking for the first signs of spring. See if you can find a female osoberry, and keep checking back in early summer. Maybe you’ll get lucky and find enough plums to make jam.

Gaultheria shallon

Originally published in The Native Plant Press December 2013

In addition to being one of the most common of the Pacific Coast endemics, salal is also one of the most utilized. Salal is a dominant understory plant throughout much of its range, along the Western Slope from just north of Juneau Alaska, south to Santa Barbara County, California. It is well suited for preventing erosion, and, in a garden setting, provides habitat for birds and other small wildlife. The foliage is browsed by animals ranging from elk to mountain beaver, especially in winter. The berries (actually fleshy sepals) are food to numerous birds and animals, including humans. Hummingbirds have been observed visiting the flowers.
Salal boughs are one of the “non-timber forest products” for which commercial permits are available on Forest Service land. The specifics of the permits vary by forest, since each forest administers their own permits. Free “personal use” permits are also available.
The salal bough industry in Washington State is centered on the Olympic Peninsula. In 2000, 4 million pounds of salal was shipped from the PNW, and 80-90 percent of that went to Europe. The Washington harvest in 2002 was worth an estimated $236 million. A study published in 2006 found that the short-term response to harvesting was increased growth, but concluded that that was probably not sustainable and called for further studies.
Salal was a favorite plant of David Douglas, who introduced it to Great Britain in 1828. It was first recorded in the wild there in 1914, and has since become locally invasive in acidic soils. It has also become naturalized in parts of France.

Cocksedge, Wendy, and Titus, Brian D. Short-term response of salal (Gaultheria shallon Pursh) to commercial harvesting for floral greenery Agroforestry Systems October 2006 Volume 68, Issue 2

Report on the Floral Greens Industry
compiled by George Draffan, Endgame.org
for The Evergreen State College Labor Center
Revised Feb 20, 2006