Sunday, January 25, 2009

Southern (?) Twayblade

Another sure sign of early spring is the emergence of the Southern Twayblade (Listera australis). I put a question mark in the title, as the common name (and the specific name australis - meaning 'southern') imply that this is an orchid only of the south. In fact, its range extends from near Sarasota, Florida to the north well into southern Canada, so it could just as easily be viewed as a northern species as a southern one. In my native haunts of yesteryear in Tallahassee, Florida, these plants would typically emerge in mid-February and persist through mid-March, depending on the population -- some sites would tend to bloom earlier than others. One time, I encountered a very large plant blooming in mid-June in an area to the northwest of Tallahassee, although this is very atypical. In central Florida, the plants are right now in full bloom, with a few stragglers still showing buds.

It is hard to appreciate how small these plants are until you see them in person. In fact, if you do see one, don't look away before you mark the spot, as it will likely take you several minutes to relocate the plant. In fact, this very thing happened to me the first time I found one as a teenager in the woods behind my house. The plant itself consists of a small stem, often tinged with purple, that supports two teardrop-shaped leaves. The leaves are a bit unusual for a monocot, as they almost seem to support a small network of veins rather than having strictly parallel veins. Typical leaf size is about 1 inch long by 1/2 inch wide, although especially large plants can have larger, wider, almost-round leaves about 1.5 inches in diameter. I have seen around 35 flowers on these more robust plants, where the typical flower count is around 8 or 9 per stem. The flowers themselves are about 1cm long and 2-3mm wide...extremely small and difficult to appreciate without the benefit of close up photography. Seedlings consist of just a pair of leaves without the flowering stem.

Below is a photo of a typical plant.



The flower structure, although miniaturized to the point that only a few hundred cells make up the petals, are still a typical orchid flower structure. Arranged around the central column is the usual cadre of three sepals, two petals and a disproportionately large lip. The lip curls around the column and then extends downward a ways before forking into two lobes. From a distance, these flowers look like pinheads with small threads glued onto them. Below is a closeup of just the flower.



Below are a few more shots taken during this same field trip.





Enjoy!

---Prem

8 comments:

Unknown said...

Hey man, great shots of the listera. I have to finish some mapping of the area in Sarasota County then I'll be ready to go find the Listera here.

Prem said...

Awesome! Keep me posted on the progress with finding that population. Too bad I can't drive down and join you for the survey. I would imagine that plants in your area would be setting seed pods now, but should still be up for awhile. Seedlings tend to persist longer into the year than mature plants.

Anonymous said...

Hi Prem, thanks for showing us this delicate delight! It is good to know the range is so varied too. Might I find one in the woodlands of SE TN?
Frances at Fairegarden

Unknown said...

Great post on listera orchids. The photos are awesome! I have always been fond of native orchids.
Phillip
1888Orchids.com

Town Mouse said...

Prem,

So glad I found your blog. My in-laws live in Florida, and it's seemed like nothing but strip malls to me. Next time I go, I'll check out all the links on your site. (Love the orchids, too, of course)

pedromiramis said...

Great to compare this species with the European Listera ovata (or as it is now put by most botanists, Neottia ovata). Ovata has green colored flowers, probably with the same small size.

I'm interested in any color variations, especially the white ones of orchids with red or purple standard color, as you can find at http://www.albiflora.eu

cheers, peter

Sunita Mohan said...

Interesting! I'm so used to associating orchids with epiphytes that its surprising to see a terrestrial (dumb I know, considering the number of Spathaglottis and Arundinas in my garden). But this is a beauty! It looks so delicate.

Dr. Know said...

Well done photos of subjects that generally go unnoticed due to their environment or diminutive stature.

These will be morose reminders when the entire state is finally converted into a contiguous condo/shopping mall. :-o

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