Spring Coral Root Orchid

Coral Root Orchids- click to enlarge

Mark Bower recently led us to some orchids he had found.  I expected to see some bright colored small flowers but instead nearly stepped on the little skinny brown stems.  They were initially unimpressive to say the least.  I had to bend down to tell they were orchids.  Like most things in nature the beauty is in looking close and fun is in knowing their story.  Mark identified these as spring coral root orchids.  I asked him to give us details on their lifecycle and it turned out to be fascinating.  Here are Mark's words.
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The orchid family is the largest family among the flowering plants. Ten percent of all seed-forming plants are orchids, with the great majority of species living in tropical and sub-tropical regions.

All orchids rely on fungi during development. They produce very small seeds which are virtually devoid of nutrients. The seed cannot germinate and develop without first being “infected” by the proper fungal species. Once infected, however, the maturing embryo will derive all of its nutrients from the fungus. Most orchids will eventually begin photosynthetic activity and provide their own nutrition, although they will maintain their relationship with the fungi.

Coral Root - Mark Bower

There are about 200 orchid species (out of 28,000) which never produce chlorophyll (acholophyllus) and remain completely dependent on fungal mycelia for their nutrition. This is felt to be a one way street, with the fungus receiving no benefit in return.

One example of an achlorophyllus orchid is the spring coral root, Corallorhiza wisteriana, which is one of Missouri’s native woodland species. It may lie dormant underground for years, all the while being sustained by its mycorrhizal fungal partner. When it does emerge in spring, it forms a purplish brown stem which lacks leaves. The flowers are short-lived and appear nondescript unless examined closely.
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Thanks Mark.

Ladies tresses orchid - Mark Bower

This month's Missouri Conservationist magazine has a feature article on Missouri orchids which focuses on the more colorful species such as ladies' tresses and yellow lady's slippers.  The ladies' tresses above is one of several of the fall-flowering Spiranthes genus.  They are so named because of the spiraling presentation of the blossoms along the stem.

The flower has the typical arrangement of petals as described in Wikipedia.  The medial petal called the labellum extends downward and out, sort of a Mick Jagger look.  This provides a platform for pollinators to land on.

Labellum with a green lower surface - Mark Bower

• The Conservationist article quotes our own Dave Ashley on his studies of pollinators on prairie fringed orchids. I would encourage you to read it here.
• This PDF is a good visual summary of the life cycle of an orchid.