Dandelion Flowers

L- Common Dandelion plant  R-Atypical Dandelion flower

L- Common Dandelion plant R-Atypical Dandelion flower lacking ligules

Common Dandelion (Taraxacum officinale) is a European species that is naturalized in Michigan. First recorded in the wild in 1837 when it was already well established. Brought here by the earliest settlers as a winter source of greens high in vitamin C they were eaten in the winter and early spring to prevent scurvy. The specific name officinale means “of the shops” and alludes to this useful plants value as a cash crop.

L- Dandelion flower head R- Dandelion seed head

L- Dandelion flower head R- Dandelion seed head

Dandelions are distinctive when in flower or seed. Be careful if you gather plants for greens. They are best when just coming up before they flower. Their deeply toothed leaves and milky juice help to distinguish them but there are look-a-likes. And of course never gather greens from lawns that have had chemicals sprayed on them.

L-Sectioned Dandelion seed head  R- Ray floret with parts labeled

L-Sectioned Dandelion seed head R- Ray floret with parts labeled

What most people call a Dandelion flower is actually a many flowered head. This is true of all members of the large Aster (Asteraceae) family. At the base of a Dandelion head is a group of green bracts called the involucre. Dandelions have only one type of flowers, ray florets. Some members of the Aster family, for example daisies, have ray and disk florets. Ligules are the “petals” of the dandelion flower. Rarely you will find Dandelions where they are absent. The fuzzy ring at the base of an individual flower is the pappus. This develops into the feather-like structure of the seed. Pappus characteristics are needed to separate some species in this family. The involucre is composed of the phyllaries which are the green bracts under the flowers. The florets are held in the receptacle. See Brian Johnston’s post on Microscopy-UK for more photos including some great microscopic images.

Go outside, pick a dandelion flower head, and take it apart. Look at the tiny flowers under a magnifying glass. Try to find the pappus. Understand the structure of this flower head as a first step to learning about the fascinating Aster Family.
Copyright 2015 by Donald Drife

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Lawn Weeds

Anagallis arvensis Scarlet Pimpernel Flowers

Scarlet Pimpernel Flowers

Scarlet Pimpernel (Anagallis arvensis) also called Common Pimpernel is known from Michigan’s Lower Peninsula and is probably more widespread than records show. It is a member of the tropical Myrsine Family (Myrsinaceae) which contains about 1000 species in 35 genera. In Michigan the family has 13 species, not all native, in 3 genera. The flowers are red, blue, or white. The blue flowered type can be called Anagallis cerulea or Anagallis arvensis var. cerulea or Anagallis arvensis f. cerulea depending on whether you treat it as a distinct species, variety or form. Leaves of the red flowered type have their undersides covered with glandular dots. The blue flowered type lacks these glands. The flowers of all the color types open in the sunshine and close during cloudy weather giving it in the eastern U. S. the common name “Poor-man’s weatherglass.” It is a native of Europe, north Africa and west Asia. This is an annual species which is uncommon for most weed species. The red flowers, square stem, and glandular leaves make this an easy plant to identify.

Anagallis arvensis Scarlet Pimpernel leaves

Scarlet Pimpernel leaves

 

Salt Marsh Sand Spurry, (Spergularia marina) was first collected in Michigan in 1974 along a highway right-of-way.  It is native along the coasts of North America and grows at the edges of saltwater marshes. I found it for the first time along Maple Road in Troy, Michigan. It did not grow outside of the area that gets salt spray from the road. I did not know what it was but I was pretty sure that it was in the Pink Family (Caryophyllaceae). I ran it though the key in Voss and Reznicek (Field Manual of Michigan Flora). As often happens, once I identify a plant I find more colonies of it. I found it in Macomb Co. and also on the campus of Oakland University. Both of these colonies grow along sidewalks that are salted in the winter. The fleshy narrow leaves, five petaled pink flowers with three stamens, the salt loving habitat, and the short stature of the plant identify it. This species is also known by the newer name Spergularia salina.

Spergularia marina Salt Marsh Sand Spurry

Salt Marsh Sand Spurry

 

Stork’s Bill (Erodium cicutarium). This Mediterranean native was first found in Michigan in the early 1870s. It has become more common in the last decade and is now found throughout the state. I knew of a single station for this species in Oakland County in the 1970s. Now I know of dozens of locations. The seedpod gives the plant its common name. Erodium comes from the Greek word Erodios, which means heron. The entire plant can be used to produce a green dye. Stork’s Bill is identified by its sprawling habit, divided hairy leaves, and five-petaled pink flowers. (See Green Deane’s “Eat the Weeds” website for more info.)

Erodium cicutarium Stork’s Bill

Stork’s Bill flowers and seedpods

Copyright 2013 by Donald Drife

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