June-August

Potentilla is another genus that gives botanists headaches.  There are about 14 species in Michigan, two are listed as threatened and a couple are widespread exotics.  Other species are found around the globe on suitable habitat.  P. norvegica may be the one we are most familiar with, but there are other common species in Michigan, too.  The yellow flowers are rather conspicuous and resemble the pink or white "wild rose".  

This plant is locally abundant along roadsides near the Great Lakes.  Found naturally on gravel beds, usually near water.  The compound leaf has toothed margins and loosely resembles strawberry.  Flowers are numerous and vegetation forms a soft mat along roadsides.

June-July

                    

Wild parsnip is an exotic species from Europe, probably escaped from cultivation.  It's a tall plant, about four feet tall, with "yellow umbrellas" at the top.  Individual flowers are small and may appear sort of waxy.  They never quite look like they have fully bloomed.  The plant is somewhat carrot-like looking.  It doesn't grow in the really dry, barren places along the road, but more towards a ditch in moister soil.  Juices from this plant can cause a nasty rash or blisters, especially on hot, humid days when bare skin comes into contact with the plant. Caution!

July-October

               

Sow thistles look like giant dandelions with bigger flower heads and prickly leaves.  There are usually 2-3 flower heads per plant, although this may vary.  While the heads may look like a single flower, they are actually many small flowers with one of several functions. 

May-September

       

Butter 'n Eggs is a pretty European species in the snapdragon family.  The blooms are whitish with a strong yellow-orange color.   Some blooms resemble popcorn more than "butter and eggs".  The flowers have a long "tail", characteristic of the flowers in this family.   Butter 'n Eggs are often found in small colonies.

June-September

 

A genus of both native and exotic species, the dozen (or more) hawkweed species are difficult to distinguish but as a genus are easy to recognize.  There are few orange flowers, especially along roadsides.   Hawkweeds look like orange dandelions on slender stalks, but there is no milky sap.   The intensity of orange varies, some are even yellow. 

June-September

            

Mullein is easy to identify year-round.   The tall, thick flower stalks are topped with a large spike of yellow flowers.   The large, fuzzy, soft leaves are mostly in the lower parts of the plant.   During the winter, mullein leaves stay green and the dry, brown stalks usually persist late into the season. 

August-Sept

              

The showy goldenrod blooms might be the most conspicuous color along roadsides and in old fields during the later summer and early autumn.  Sometimes goldenrod forms sweeping "seas of yellow" across large open areas.  The plants usually stand 2-3 feet tall and have variously-shaped flower spikes.  There are at least a couple dozen species.  Houghton's goldenrod is on the Michigan threatened plant list, but it is not a roadside species.

August-October

             

Tansy has bright yellow flowers in broadly round-top clusters.  Individual flowers look like mini chrysanthemums but are usually no more than a half-inch wide, but clusters may be 4-6 inches wide.  The plants stands about four feet tall.  Crushed leaves have a spicy smell to them.  The exotic plant is widespread across Michigan but is not considered highly invasive.  It most likely escaped from flower gardens.

June-October

              

Black-eyed Susan is another one of those very familiar summer time flowers.  The dark brown center and cheeful golden "petals" can found along roadsides throughout the state.  The blooms may be up to three inches wide and the plants reach a height of up to three feet.  Some people might refer to Black-eyed Susans as yellow daisies, although daisies are another genus altogether. 

May-September

 

Hop clover is an inconspicuous small flower that grows close to the ground.  The clusters of tiny flowers are about 1/4 to 1/2 inch in length.  The leaves have that distinction "clover look" to them.  Most of the clovers in Michigan are exotics from Europe, including hop clover.   And like its cousins, it has escaped from cultivation as forage crops.

June-August

               

Birdsfoot trefoil is a brilliant yellow flower that blooms during the height of summer.  Along roadsides it can form solid stretchs of dense vegetation, as well as large sweeping patches in old fields.  It is classed as mildly invasive and is often used as cover in deer openings.  It won't grow in shade.   While native species are often preferred for wildlife plantings (if you really want any), the seed is often hard to come by.  Birdsfoot trefoil and clover seed stock is readily available. 

June-September

Scruffy-looking, five-part flowers with lots of stamens will help identify St. Johnswort.  Flowers are not a bright yellow and petals often appear rather crumpled.  There are about a dozen species in Michigan.   Most tend to have loose clusters of flowers at the top of the plant, which usually stands 2-3 feet tall.

April-July

 

Buttercups have rather small flowers with five petals.  Sometimes the petals are notched and flowers look like they have more than five petals.  Plant heights vary considerably, from a foot to several feet, depending upon the species and site.  There are many species of buttercups in Michigan.