Friday Flower – green fringed orchid

I may have been the “Beetle Group” leader for last May’s BioBlitz at Penn-Sylvania Prairie, a 160-acre tract of native tallgrass prairie in southwestern Missouri owned by the Missouri Prairie Foundation.  However, it was a plant – specifically the green fringed orchid  (Platanthera lacera) – that would prove be the highlight of my visit.  I’ve already lamented the paucity of beetles that I found at the prairie and the possible reasons for such.  It’s a shame, because to my knowledge the BioBlitz was the first real attempt to begin documenting the diversity of beetles and other insects that inhabit the prairie.  This is in great contrast to the vascular plants, of which about 300 mostly native prairie species have already been recorded from the site in active survey efforts that began even before its acquisition.   It’s no coincidence that prairie plant diversity would be so high in this frequently burned prairie remnant while beetles and other insects would be rather hard to find, since vascular plant diversity is the primary – and often the only – metric used to assess the success of and optimal timing for prescribed burning in native prairie remnants.  Unfortunately, the response of invertebrates to fire-centric management techniques such as those used here have not been so well considered, with the apparent declines in their populations now fueling an increasingly acrimonious debate on the subject.  But I digress…

Also called ragged fringed orchid, this species typifies the rather striking appearance of the genus as a whole.  I’ve always been quite enamored with orchids (even possessing a small collection during my young adult days that I grew outside under shadecloth during summer and indoors under artificial light during winter) but have encountered only a small fraction of Missouri’s 33 native orchid species – mostly in the genus Spiranthes (e.g., Great Plains Ladies’-tresses).  Despite not having seen this genus prior to this day, I knew immediately what I had stumbled upon (at least at the generic level) as we scoured the prairie in our search for its meager scraps of beetle life.  While not listed as threatened or endangered in Missouri, it is still quite uncommon, with populations scattered across the Ozark and Ozark Border counties and occurring with greater frequency in these Osage Plains in a variety of open, acidic-soiled habitats (Summers 1981).  As is typical for species with green-white colored flowers, the blossoms emit fragrance at night and thus attract sphinx moths (family Sphingidae) and owlet moths (family Noctuidae) for pollination, including the hummingbird clearwing hawkmoth (Hemaris thysbe) (Luer 1975).  While our Midwestern populations are considered “spindly and unattractive” compared to the more luxuriantly-blossomed plants of New England and maritime Canada (Luer 1975), I consider this to be the most strikingly handsome orchid I’ve encountered to date.

Photo Details: Canon 50D (ISO 100, 1/250 sec) w/ 100mm macro lens @ f/10 (whole plant) or f/18 (flower close-up), Canon MT-24EX flash (manual, 1/4 ratio) w/ Sto-Fen diffusers. Typical post-processing includes levels adjustment, minor cropping, and/or unsharp mask.

REFERENCES:

Luer, C. A.  1975. The Native Orchids of the United States and Canada Excluding Florida.  The New York Botanical Garden, 361 pp. + 96 color plates.

Summers, B.  1981. Missouri Orchids.  Missouri Department of Conservation, Natural History Series No. 1, 92 pp.

Copyright © Ted C. MacRae 2010