by Dr. F. Alice LeDuc
Geranium – Geranium molle – Dove Foot; G. oreganum – Oregon Geranium; in addition G. robertianum – Herb Robert; G. dissectum – Cutleaf Gerenium
I was talking with my niece about the wildflowers blooming in her yard. She told me she had at least three species Geranium. This is not the Garden Geranium that you are probably familiar with. That is the Genus Pelargonium, they are mostly native to South Africa.
The above listed four species of Geranium can be found in our area. They all have purple to lavender flowers, occasionally you can find a white one. Of importance is the last listed species G. dissectum. This species is native to Europe which is an immigrant to North America. In all probability it came as weed seed in the various grains and other seed brought by the first colonists. So technically this species is a weed. Just remember a weed is a plant out of place.
Let us look at the characteristics that help us tell the four species apart. First is Geranium dissectum, usually and annual plant, easily identified by its highly dissected leaves; from which comes the Common name Cut-leafed Geranium. The leaves are palmately veined and dissected into five to seven lobes with oblanceolate segments. The stems, ascending or erect, are hairy with rough hairs of which some are gland tipped. The petals are five like all of the geraniums I will be discussing. The petals are distinct in they are lobed with an indentation in the middle of each petal. The plant has sender, deep roots.
Another two species are mainly annuals though sometimes biennial. That means the seed germinates in the fall and goes through the winter as a rosette of leaves close to the ground. Then in the spring it sends out stems with flowers at the terminals. It flowers seeds and dies. First consider, the species is Geranium molle, Dove’s Foot is native to Europe and probably introduced. However, it poses little to no danger to our ecosystem. This plant like the other plant has roots that are slender and short. The Leaves look round in shape but are divided into segments palmately arranged round the leaf petiole. The segments are lobed at the tips. The second species G. robertianum is a plant found throughout the Northern Hemisphere and possibly introduced to our region of Oregon by the early settlers. Its leaves are more oblong in shape, compound with three leaflets, but quite dissected, the lower two are palmately lobed with deep segments, while the terminal leaflet is more elongate with segments that appear pinnate, that is segments arranged along both sides of the main midvein. When crusted the leaves have a somewhat fetid odor hence the name Stinky Robert.
The final species the one that is a true native species, is Geranium oreganum, a true perennial plant. So, its roots are deeper in the soil. The leaves are roundish in shape and divided into five to seven oblanceolate segments. The stems are hairy with some soft and some glandular tipped.
All species flower from spring to mid-summer though some may start earlier and some bloom later into August. Concerned with which are considered weeds, first consider if it is likely to take over areas in your garden, if so, weed it out. Second is it native, and does it have attractive flowers and foliage, if so, is it worth allowing to be in your garden. The nonnative plants are annual and biennial that go to seed every year thus creating many more plants. The final question is how much effort do you wish to spend in your garden. Remember you can always enjoy the flowers and plants as you travel, walk or hike through our local region.
