Monday, March 28, 2011
Few-flowered Rein Orchis (Platanthera sparsifolia)
The Few-Flowered Rein Orchis is another of the green Platantheras, all of which are rather uninspiring as orchids go and often somewhat difficult to tell apart. This one was rather easy to identify, but nothing to brag about, though a new species for us.
The species reaches the northern edge of its distribution in southern Washington State, but we saw it in northern California and southern Oregon, where is is abundant, growing in clumps of hundreds of stems in some places, and scattered stems elsewhere.
The plant with its flower spikes can be quite tall, growing over 75 cm, but is often shorter, especially in strong sunlight. Like most of the plants in the genus it likes wet areas and is often found growing in serpentine seeps, as we found it growing on our recent trip.
When found in serpentine areas it is often associated with the California Lady's Slipper (Cypripedium californicum) and the Cobra Lily (Darlingtonia californicum). In fact, in nearly every location where we found Cobra Lilies, we also found this species.
The flowers are around 2 cm in size and the petals and dorsal sepal form a "hood" at the top of the flower, with the narrow lip hanging below and the lip-length spur behind the lip. The rest of the flower is more or less curved back. The flower count varied from few to as many as 45 flowers.
The name sparsiflora means "few-flowered" but it is difficult to see why the name was given since the flower count is no lower than the other green-flowered Platantheras. But whatever the reason for the name it is relatively easy to identify this species from the shape of the flowers.