Northern Minnesota phenology for July 2014: Orchids

By: John Latimer

purple fringed orchids by blueridgekitties
Purple fringed orchid. CC-licensed photo, click for original.

The ditches in northern Minnesota are punctuated with the purple-fringed orchids in the last half of July. Tall magenta stalks of multiple flowers stretch above their neighboring plants. A casual glance might have you thinking fireweed, another tall magenta flowered plant also blooming at this time of year. But the fireweed has a wider flower head and grows much taller and in dense patches. Both have flecks of white on the flower but the white of the fireweed is much more obvious. The purple-fringed orchid shines as a narrow exclamation point of pure magenta.

Purple-fringed orchids belong to the genus Platanthera, literally Greek for “wide anther” a feature found on the flowers this group. Worldwide there are about 200 species within this genus. In North America, there are 37 recognized species, and eleven of those are found in Minnesota. All of the members of this genus in Minnesota feature tall, slender, leafy stalks topped by a spike of multiple flowers. The flowers all feature a spur of varying lengths that dictates which insect will be its pollinator. In the case of our purple-fringed orchid the spurs are quite long, ranging from 1.7- 2.3 cm. This eliminates the bees and flies from pollination and the task falls upon the butterflies and moths that possess the necessary mouthparts to reach the nectar. The orchid’s full scientific name is Platanthera psycodes and the second epithet translates as “of butterflies”.

Propagation by seed is just one aspect of the P. psycodes. Below ground the plant produces a tuber, basically a carrot like structure that stores energy to re-create the plant next year. At some point during the summer the plant creates a second tuber that will supplant the first. This second tuber will have flower bud at the top and buds to create roots at the bottom. As this second tuber develops first tuber withers and disappears. Whether the plant will have flower the next year or just a vegetative stem is determined as this second tuber develops. Whatever the case, it is essentially a brand-new plant in the same location the following year.

Purple orchid closeup. CC-licensed photo, click for original.
Purple orchid closeup. CC-licensed photo, click for original.

The fact that the purple-fringed orchid renews itself each year makes locating them year after year an easier task. If you discover them one year, chances are they will be back in the same place the next year. Among the places I find them most often are ditches. Not all ditches are created equal however, and those shallow and moist ones offer the best chance to view these flowers. Though they prefer wetlands, they don’t want to be too wet. Bogs and swamps, cattail marshes, and peatlands all have much too much water. If you’re walking around looking for these orchids, the ground should be firm underfoot, not squishy. Other potential sites that may hold these flowers are brushy thickets with alder or dogwoods, or in meadows often associated with beaver ponds, especially those where the beavers have abandoned the area. They can be found in transition zones away from some beaches as well. Not in the wave-washed sands, but more likely in the area where permanent vegetation begins to grow. Keep your eyes peeled for stalks of magenta and move in close for a look at the fringe that gives them their name.

From the phenology notebook:

July 1, 2013       Harebell are starting to bloom and the second aster of the season, northern heart-leaved has flower buds. Soon the blues will predominate. I see a monarch butterfly today and they have been so absent that each sighting is worth noting. Before this day is done I will have seen three but it is still a paucity when compared with other years. Two of the noxious hawkweeds are gone to seed today. The orange hawkweed, sometimes mis-identified as Indian paintbrush, and perhaps appropriately called “the devil’s paintbrush” and the Canada hawkweed are both invasive and aggressive. Whenever I find them on my property I uproot them and bury the plants deep.

July 13, 1999     Steady rains over the last few weeks have brought the Prairie River to flood stage. The county district road foreman reports that the water is 30 inches above the road. Wood thrushes continue punctuating the dawn and dusk each day with their glorious songs. Water hemlock is at its peak of bloom, and the first purple-fringed orchids have started to flower. The tall meadow rue is done flowering for this year. In another six weeks the leaves will fade to yellow tinged with purple. Saint John’s Wort is at the peak of bloom; some say a tincture of the plant has a calming effect on frayed nerves.

July 31, 2001       The month of July in this first year of the new century ends with the large-leaved asters at their peak of bloom. The ditches are spiked with purple-fringed orchids. The Canada anemone and the water hemlock are in decline for another year. Tall blue lettuce is flowering though spotting the flowers can be a challenge. Often they seem as if they are hardly open and the blue of the flower is so washed out as to be nearly white. I see the first flock of migrating monarch butterflies today. I wished them a safe journey.

 

John Latimer is well known throughout northern Minnesota for his phenology work.  John appears weekly on KAXE radio in Grand Rapids, and audio and twitter archives are available here. We hope his work will be a frequent feature on MyMinnesotaWoods.  This article also appeared in the Duluth Senior Journal.  It is printed with the author’s permission.

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