Missouri Orchids – (Platanthera flava var. herbiola) – Tubercled Orchid

Here is my last new orchid for the season. It is also probably the orchid I had to work the hardest to find in this entire project. Platanthera flava var. herbiola is classified as S2 (imperiled) in Missouri due to the very few remaining populations. This is an orchid that likes its feet wet and can be found in a variety of habitats containing moist to wet soils. After trying unsuccessfully in 2020, Pete and I went back to the same location this year – a wet prairie in southern Missouri in early June. This was very tough searching as the high temps, strong sun and saturated air created a potentially dangerous heat index. We tried our best, slowly slogging through the already quite thick prairie. Just when it looked like Pete was wanting to throw in the towel, we came across a patch of less-dense vegetation with water about ankle-high. Here we found young orchids that numbered in the hundreds. Unfortunately, most were on the early side and were not fully flowering but we did find a few that made us happy. We also found that many of the orchids in this group had grazed top leaves – most likely from white-tailed deer that usually find orchids to be very appetizing.

Platanthera flava var. herbiola, the 33rd Missouri orchid species I have been able to see and photograph.

There is another variety of this orchid, P. flava var. flava that is also found in Missouri. Recently Pete and I tried to find this in most of the known locations but came up short. As of now my quest stands at 33 of 36 orchid forms that can be found in the state (36 is my accepted number and others may disagree). In addition to P. flava var. flava, I also need to find Coeloglossum viride (Long-bract Frog Orchid) – this species is known from a single location in the state but apparently does not flower and Epipactis helleborine, the broad-leaved helleborine – the exotic orchid that is becoming naturalized in this state but originates in Asia and Europe. Finding these three remaining orchids should be quite the task and I look forward to attempting these next year.

The longer floral bracts, looser inflorescence and three leaves are among a few of the characteristics that identify this as Platanthera flava var. herbiola and not P. flava var. flava.

I have run into a couple other circumstances in our orchid flora where intermediate forms have caused problems in determining the identity of a plant or population. Where these two varieties overlap, as they seem to do in Missouri, there are intermediate forms between these two varieties as well. I will hope that when I do find a potential flava variety that this will not become a problem.

Platanthera flava var. herbiola is the more southern variety. Here another distinguishing characteristic can be observed – the lip of variety herbiola is longer than it is broad, whereas the lip of variety flava is as broad as it is long, being almost square or circular in appearance.

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