Thursday, June 9, 2016

Wildflowers of 2016 - #90 through #94

I am making a push to get caught up on my Wildflowers of 2016 list.  The following species were found at Mill Pond Park on Thursday May 26th.

Wildflowers of 2016 - #90 Pawpaw (Asimina triloba)

Reddish-purple Pawpaw Flowers dangle from the branches

Species number ninety for the year is the Pawpaw (Asimina triloba).  There is a single patch of this understory tree species growing in Mill Pond Park.  It was originally a single tree (of unknown origin), but it has greatly expanded by sending up sprouts from its roots in recent years.  In June 2013 I wrote a profile of this species that can be found here.

Pawpaw flowers have three large and three small petals.

Wildflowers of 2016 - #91 Field Hawkweed (Hieracium caespitosum)

Field Hawkweed (Hieracium caespitosum) is known by several names:  Meadow Hawkweed, Yellow Hawkweed, King Devil.  There are fifteen Hieracium species recorded in Michigan, seven of which are native and eight introduced including Field Hawkweed.  Field Hawkweed has been recorded mainly in the southern half of the Lower Peninsula.  Nationally, it has been documented in both eastern and western states, but is absent from records for the Southwest and most of the Great Plains.

Field Hawkweed - note basal leaves and hairy stems
Of the fifteen species, eight have only or mostly basal leaves (with no or a few stem leaves).  Of those eight species, two can be eliminated based on the fact that they have single flowers (rarely as many as three) on each stalk.  An additional species can be eliminated because it has orange flowers.  The plants that I found had no stem (cauline) leaves, which eliminates two additional species.  Rattlesnake-weed can be eliminated because it has dark purple veins in its leaves.  This leaves only H. caespitosum and H. piloselloides as possibilities, both of which are known as Yellow Hawkweed or King Devil.  Of these two, only one (H. caespitosum) has densely hairy flower stalks, giving my my identification..

Wildflowers of 2016 - #92 Nannyberry (Viburnum lentago)

Naannyberry (Viburnum lentago) is a native understory tree/shrub.  It can grow to a height of 10 to 25 feet.  Nannyberry prefers rich, damp soils found in swamps, floodplains, wet meadows, and stream banks.  It is primarily a northern species, being found mainly from the Ohio River and Chesapeake Bay north into Canada, and as far west as Montana, Wyoming, and Colorado.  There is a disjunct population recorded in Georgia and Mississippi.


The white flowers of Nannyberry are small (less than 1/4 inch across).  Flowers grow in  flattened flower clusters known as a cymes that measures about 2.5 inches across.  Each individual flower has five petals.  Once pollinated, the flower ovaries will develop into blue-black edible drupes that measure just around 1/2 inch long.  The fruit is reportedly delicious and is eagerly consumed by wildlife when ripe.

Nannyberry flowers grow in a flattened cluster known as a cyme.

Wildflowers of 2016 - #93 White Campion (Silene latifolia)

White Campion (Silene latifolia) commonly grows in disturbed sites such as roadsides, fields, shorelines, and the edges of forests.  It may grow as an annual, biennial, or a short-lived perennial.  It has been documented in the majority of Michigan's counties and in forty-two other states.

White Campion
White Campion is easily identified by its white flowers with five deeply notched petals and an inflated calyx (bladder) formed by the fused sepals of the flower.  White Campion can be found blooming from Spring through Fall.  The entire plant (stems, leaves, calyx) is covered with dense white-gray hairs. 

White Campione is one of many introduced species that have had a neutral to slightly positive effect on the environment.  It is not part of the original flora of Michigan, but it is not aggressive and doesn't crowd out native species.  It's white flowers typically open in the evening and attract a variety of moth species, especially Sphinx moths.

Wildflowers of 2016 - #94 Illinois Carrion Flower (Smilax illinoensis)

The final flower of the day was Illinois Carrion Flower (Smilax illinoensis).  I have previously identified this plant as Upright Carrion Flower (S. ecirrata), but am changing my identification based on several factors.  The flowers of this plant are whitish-green and grow in globe-shaped clusters that help this plant live up to its name - the flowers smell like rotting meat.  The plant uses this smell to attract flies which serve as their primary pollinators.

Illinois Carrion Flower - note how leaf size decreases from the bottom of the plant to the top

The flowers of Upright Carrion Flower grow in clusters of fewer than twenty-five while those of Illinois Carrion Flower grow in clusters of more than twenty-five.  This colony of plants has flowers that grow in clusters of more than twenty-five.    Both Illinois Carrion Flower and Upright Carrion Flower can be distinguished from the three other species of Carrion Flower that are found in Michigan by their upright growth pattern (the other species are all vines) and the general lack of climbing tendrils, although a few tendrils are present in the upper leaf axils.  

Illinois Carrion Flower - note globe-like cluster of (25+) greenish flowers

Other differences between S. illinoensis and S. ecirrata include the shape of the leaves - S. ecirrata leaves are heart-shaped instead of rounded at the base (as in S. illinoensis).  Also the upper leaves of S. illinoensis are smaller than the lower leaves.  In S. ecirrata, they are of a consistent size.  Based on the flower differences and leaf differences, I identified this plant as Illinois Carrion Flower.

No comments:

Post a Comment