Monday, May 26, 2014

Orchidaceae - Cypripedium spp. - Orchids - Orchidées

I photographed two species of orchid at the lake this weekend. Both are native to the area; one is rather common and the other exceedingly rare.

The more common species is Cypripedium parviflorum var. pubescens (large yellow lady's slipper, fr: Sabot de la vierge). It is an extremely distinctive flower of the family Orchidaceae; its conservation status is not listed in Canada (species profile at Plants of Canada database) as far as I can tell, but it is listed in the US as threatened or endangered in several states (USDA species profile). Other sources, bafflingly enough, list this flower as abundant in Canada. As it stands I'll stick with the information provided by official sources and assume that C. parviflorum var pubescens is either not at risk in Canada or unresearched here.

My (purely anecdotal, entirely biased, completely unreliable) personal observational sense would suggest that this species is not particularly rare at least in Gatineau, as it appears to be relatively abundant. Mind you, I'm talking about a relatively small plot of land which is unusually well-protected, so perhaps my perception is skewed by their relative commonness in the area where I usually spend my outdoors time. In any case, I counted 61 individuals in a 15"x10" plot just by the driveway of the house this weekend, including one clearly mutated individual which had two flowers on the same stalk (this species is supposed to have a single stalk with a single flower at the top). There are a number of populations scattered around the property, most of them as large or larger than the one we surveyed.

It is quite a charming flower and remarkably fragrant, a characteristic quite common in the Orchidaceae. It also displays the Orchidaceae apomorphies of bilateral symmetry and heavily modified petals.

Stand of C. parviflorum var. pubescens

C. parviflorum var. pubescens flower in front view
This front view of the C. parviflorum var. pubescens flower shows nicely the bilateral symmetry characteristic of the family. I've always been quite charmed by the way the sepals curl in this flower.

C. parviflorum var. pubescens lateral view
This image shows a bit more clearly the heavy modification of the three petals. The large, bulbous portion of the flower is one petal; the other two are curled together at the centre of the flower over the opening in the first.

The other species I photographed at the lake is a bit more unusual. Cypripedium arietinum (ram's head orchid, fr: cypripède tête de bélier) is rare and listed as a species at risk in Quebec. It is also listed as threatened or endangered in the US. The colony on the property seems to be relatively prosperous for the moment; last year we counted about 200 individuals along about 500"x30" (they are distributed roughly in a strip near the shore of the lake); this year we counted 132 individuals and saw evidence of deer predation on the orchids (clipped/bitten plants). We are considering putting protective cages around some of the more accessible plants to see if we can't cut down on deer predation for this vulnerable population.

This species also displays the interesting apomophies of the family listed above.

C. arietinum
I think this is a fairly nice specimen photo of this flower. I'm pleased with the way it came out. I've also always loved the spiderweb-like patterns on this orchid. It is much smaller than the Large Yellow Lady's Slipper and considerably harder to spot in the woods. It takes a fair bit of effort to locate individuals among the brush; they are shorter, the flowers are smaller, and the flower profile is much more subtle from above (the upper sepal overhangs the flower, hiding it from view and having a tendency to make the plant look a whole lot like just another Streptopus amplexifolius or Maienthemum racemosum.

C. arietinum

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