Of my many enjoyable botanical experiences of 2010, I would rank highly the afternoon I spent with Brian Carson of the Ottawa area in early June. Brian is an avid Trillium enthusiast, and especially keen on finding double-flowered individuals in the wild. Given the rareness of double-flowered trilliums, this necessitates a lot of exploration — and that experience in seeking out wildflowers in forests made Brian an excellent guide (I don’t often get taken to see plants, instead either leading others or exploring on my own). Among other things, Brian took me to see a very densely growing population of hundreds of Cypripedium acaule, or moccasin’s flower, growing with little else in the pine needle duff of (what I vaguely recall to be) a Pinus resinosa plantation.
If you’re a long-time reader of BPotD and have a sense of plant biodiversity, you’ll know that terrestrial orchids of North America are hugely overrepresented on Botany Photo of the Day in proportion to any other grouping of plant species. To me, though, they are some of the first species I recognized as such — it helped growing up near two ecological reserves in Manitoba set aside specifically for preserving orchid species (Libau Bog and Brokenhead Wetland). However, despite all the orchids nearby, I only remember observing a few plants of Cypripedium acaule in a single location in the Mars Hill Wildlife Management Area during my time there (MHWMA was even nearer to my home). It was a special treat to see hundreds of plants, even though the species itself is widespread in eastern North America and extending into boreal western Canada. In some jurisdictions, it is rare or endangered (e.g., Illinois).
The Manitoba and Quebec locales where I’ve seen Cypripedium acaule both had the well-draining (sandy) and acidic soils with partial shade typically preferred by the species. I saw two other plants in bloom during that early June trip in Ontario at the Mer Bleue Conservation Area near Ottawa, but these were growing in sphagnum and with more exposure to the sun.
The epithet acaule means “stemless”, so named because the flower is borne on a scape: a leafless axis that arises directly from a caudex or rhizome at or near the surface of the ground.