Thursday, July 29, 2010

Long-bracted Green Orchis (Dactylorhiza viride var. virescens)

The Long-bracted Green Orchis is named for the bracts under each flower which are longer than the flowers and give the flower spikes a rather feathery appearance.  The genus is found around the world in the Northern Hemisphere and has only the one species, though there are several varieties, two of them found in the Pacific Northwest, though one only in very limited alpine areas.

This variety is the more common in North America (the other is found only in Alaska, but is very common in Europe and Asia).  It is considered "rare to local" in the areas where it can be found, but this may be due in part to the fact that unless seen close-up, it resembles many of the green-flowered Platantheras, and when we found it was actually growing among them.

We had stopped along the road to take pictures of a field of Wood Lilies and had seen some Platanthera huronensis and Piperia unalascensis growing nearby.  Only when we looked closely did we notice the Dactylorhizas growing among them.  Interestingly, the other species were found in a wet area at the foot of the bank while the Dactylorhizas tended to grow a little up the bank and drier.

The long distinctively notched lip makes this species immediately recognizable.  The flowers are green and the flower parts form a sort of hood above the lip.  The flowers were quite closely arranged on the spikes and in the case of the plants we saw had about thirty flowers per spike.  The plants were about 10-25 cm in height and the flowers about 1.5 cm long.

The species ranges from Alaska to Newfoundland and south to Washington, New Mexico, Iowa and North Carolina.  We found it in Alberta in Jasper National Park along the Maligne Lake Road in July, though the information we have indicates that the flowers appear to be perfect long after they have been pollinated and that certainly appeared to be case on some flower spikes.

Note (2017): this species has recently been reclassified as Dactylorhiza and the information in the post has been changed accordingly.

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