Tuesday, April 26, 2011

Saprophytic Orchids of Indiana

There are four species of orchids with extant populations in Indiana that can be considered to be saprophytic and/or hemi-parasitic. They live their lives below ground, not subject to photosynthesis, and unable to produce their own food, but deriving it instead (via mycorrhizae) from decaying organic matter (Homoya 1993).

It is suggested that no plants are truly saprophytic, that it is not the plants that are doing the breaking down of the dead plant material, but symbiotic fungi (mycorrhiza) working with the plants that are doing the decomposing (www.helium.com).

I was fortunate to find and photograph all four species last year, but it required traveling from one end of the state to the other, beginning the first week in May and ending in the middle of September.

The first to bloom in the spring is Wister's coral-root (Corallorhiza wisteriana), which is found primarily in the southern half of the state. The flowers (below) were found in bloom on May 4, near Versailles State Park and were growing in the flood plain of a small creek and not on the moderately moist slopes of ravines where it typically occurs
(Homoya 1993).

Later in the summer in late July and August one can find spotted coral-root (Corallorhiza maculata). The flowers (below) were blooming on July 18, at Cowles Bog in northwestern Indiana.

Another mid- to late-summer bloomer is crested coral-root (Hexalectris spicata), which differs from members of the coral-root genus (Corallorhiza) by having a different column structure and thicker more unbranched rhizomes (Homoya 1993). The flowers (below) were photographed on July 20, in Clark County.

Autumn coral-root (Corallorhiza odontorhiza) is the smallest member of this genus and no doubt possesses the least showy flower, if indeed the flower can even be found in its open state. I have been monitoring a small colony of this species at Cowles Bog in Porter County for four years. Only once have I found a single open flower on any of the plants.

This is the typical flower stalk of autumn coral-root (below) with its tightly closed flower.

And here--in all its glory--is the open flowered form (below) photographed on September 19.

Sadly, another saprophytic orchid, early spring coral-root (Corallorhiza trifida), has been extirpated from Indiana. It was found in one site only, in a unique natural area in the Indiana Dunes, which is now the location of a foreign owned steel mill (Homoya 1993).

Homoya, M.A. 1993. Orchids of Indiana. Indianapolis: The Indiana Academy of Science.


A.L. Gibson said...

Great post! Hexalectris spicata put on one heckuva show down on the Edge of Appalachia preserve last summer. One its best showings in years. I also caught the Corallorhiza odontorhiza in bloom last Fall as well. Glad to see you using Homoya's Orchids of Indiana book. One of the best ever written and published in regards to our regions Orchids! I've got a copy that I can't help but leaf through all the time.

Heather@RestoringTheLandscape.com said...

Nice photos, I'm so glad you mentioned that the Autumn Coral-root hardly ever opens its flowers! A good friend found some several years ago, and like you I have gone to the location several times to photograph it but have never found the flowers open!

They're also extremely hard to see in the leaf litter!

Prem Subrahmanyam said...

I find it interesting that three of these species can also be found in Florida, two of which I have personally seen and photographed.

Prem, curator,
The Florida Native Orchid Blog

Pete said...

Thanks A.L., H. spicata is by far the showiest orchid of the bunch. Homoya's orchid book is my bible here in Indiana. He is the one who guided me to the Clark County site where the H. spicata was photographed.

Thank you Heather. Keep returning to the site and you may eventually be granted the small reward of finding one of the flowers in its open state.

Prem, my range maps show that H. spicata and C. wisteriana can be found in Florida. What is the third? C.maculata possibly?

Keith said...

About 20 years ago I found a single red-colored stalk of Corallorhiza in fruit during the first week of June. It was in woods on the border of a small lake west of South Bend, Indiana. I made a mental note to go back earlier the next year, but have never remembered to go back in spring. The site is still extant, and it seems reasonable that the plant could have been Corallorhiza trifida!

Pete said...

Wow! When can we go look for it Keith?

However,there is an accepted voucher from St. Joseph County, Indiana for C. wisteriana from June 1914 (Hoymoya 1993)

Either species would be an exciting find.

Keith said...

Whoops! Let me edit my last comment to say "it seems reasonable that the plant could have been Corallorhiza trifida or C. wisteriana!" It was probably the latter, given the red color in the stem.

Very nice post Pete, and wonderful photos!!

Pete said...

Thanks Keith, There is a photo of C. trifida elsewhere on GYBO taken by Scott Namestnik in Wisconsin. It shows the greenish stalk and flowers very nicely.

Prem Subrahmanyam said...

Pete, C odontorhiza is known rarely from the northern counties in Florida. I have yet to see this one in person.

neomyrtus said...

Wait - for a moment there I thought I was looking at Gastrodia.

I haven't even thought of Northern hemisphere saprophytic orchids (well, I admit I don't spend much time thinking about orchids).

Now I am going to have to see if these two genera are related and dig up some horrendous phylogeny.

Same subfamily, but different tribes, it would seem.