Showing posts with label Southern Twayblade (Listera australis). Show all posts
Showing posts with label Southern Twayblade (Listera australis). Show all posts

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.


Related Posts Plugin for WordPress, Blogger...