Many different yellow wildflowers have appeared recently. So this is a longer post than usual.
The first grouping includes four plants that have a “weedy” appearance. Despite this, their flowers are surprisingly attractive.
Meadow Hawkweed (Hieracium caespitosum); upper left of image
This is an invasive non-native species relatively new to Minnesota. Like the related Orange Hawkweed, it is spreading southwest in the state after its introduction in the Duluth area.
Yellow Avens (Geum aleppicum); lower left in image
This is a plant in the rose family that is found throughout the Northern Hemisphere. As is the case with most of these plants, various medicinal properties are attributed to it. More interestingly, in medieval Europe Yellow Avens was thought to protect your home from the devil.
Golden Ragwort (Packera aurea); center of image
There is a long list of ailments that are supposedly helped by application of Golden Ragwort, in particular issues with the reproductive system. However, it contains toxic pyrrolizidine alkaloids, which can lead to liver problems. It seems clear that herbal remedies like this should be used with caution.
Field Mustard (Brassica rapa); right side of image
This is a non-native species that has many cultivated subspecies. The subspecies oleifera is field mustard, which is a common weed. More useful subspecies include turnips and bok choy. A closely related species is the plant that produces canola oil (Brassica napus)
Tall Buttercup (Ranunculus acris)
Most of the ~15 buttercup species in Minnesota are native, however the Tall Buttercup is not. Its alternate name, crowfoot, comes from the resemblance of its leaves to birds feet. It is native to Europe and is considered a weed here. Of particular concern is the bitter toxic oil that it contains, protoanemonin. This is a serious irritant to grazing animals, known to cause blistering of mouths and even deaths of cattle.
Evening Primrose (Oenothera biennis)
There are eight native species of evening primrose in Minnesota, this example is the Common Evening Primrose. Its flowers open at dusk and wilt away the following day; ideal for night-pollinating insects.
The plant has a long tradition of medicinal application. Evening Primrose Oil (EPO), made from its seeds, is commercially available because of its reported healing properties. Gamma-linolenic acid, an omega-6 fatty acid, is thought to be the active healing agent in this oil. The most convincing application of EPO has been for treatment of skin conditions like eczema. Studies of other applications have more ambiguous results. Evening primrose is also edible — including its fleshy roots which can be prepared like potatoes.
Black-eyed Susan (Rudbeckia hirta)
Black-eyed Susan is a very common and popular plant; it occurs wild and is often used as a domesticated plant in landscaping. It is the state flower of Maryland.
Four varieties of Black-eyed Susan are recognized in the US. The variety pulcherrima occurs throughout eastern North America, and is likely the variety seen in Minnesota.
The origin of its name is likely the poem “Black-Eyed Susan” by the English poet John Gay (1685-1732):
Black-Eyed Susan came aboard,
and eyed the burly men.
“Tell me ye sailors, tell me true
Does my Sweet William sail with you?”
Smooth Oxeye (Heliopsis helianthoides)
Smooth Oxeye is not a true sunflower, but it is so similar that an alternate name for it is False Sunflower. It is a native plant in Minnesota, and also a popular garden plant. Smooth Oxeyes are prevalent along the roadsides in our area.
Woodland Sunflower (Helianthus strumosus) Jerusalem Artichoke (Helianthus strumosus)
Native sunflower species are similar to one another. The Minnesota Wildflower site provides tips on making correct ID’s — I believe these pictures are the two listed species, but there is some uncertainty.
The Jerusalem Artichoke was cultivated by Native Americans for its tubers, and was important food source for them. They provided Jerusalem Artichoke for Lewis and Clark to eat on their expedition. In Germany an alcoholic drink, Jerusalem Artichoke Brandy, is made from these tubers.
The tuber reportedly tastes like artichoke. The connection to “Jerusalem” is uncertain but likely is a corruption of an Italian word “girasola”; translated as “following the sun”.