Randal Mindell, a Paleobotanist here at UBC, took today's Botany Photo of the Day in the North American section of our E.H. Lonbrunner Alpine Garden. Steve Coughlin wrote the entry.

Orchidaceae is one of the largest families of flowering plants, consisting of about 800 genera and between 22000 and 35000 species that are variously native to every continent except Antarctica. As the size and distribution of Orchidaceae might suggest, the family is thoroughly diverse: species range from small plants of only millimeters in height through to specimens that reach to above 13 metres at their apex, and flowers vary from sizes barely visible through to a full 76 centimetres in diameter. While today the plants are cultivated primarily as ornamentals, humans continue to use the component parts of different Orchidaceae species as the base material of various edible and non-edible products as well, among them vanilla, salep (a flour), medicines, glue, and weaving fibers.

Epipactis is a genus native to North America that consists of around 25 allogamous, autogamous, and more rarely, cleistogamous species.

Epipactis gigantea, commonly referred to as stream orchid, is distributed abundantly along the stream, river, and lake shores of western North America. The plant's stem can grow to a height of 1 metre, bearing several lanceolate leaves along with similarly-shaped inflorescence-supporting bracts. The species, a perennial, crowns itself with up to three showy flowers, each of which has 3 sepals and 3 petals. The two top petals are a deep-veined mix of green and reddish-brown, and from the rich purple of the bottom petal hangs a small tongue-shaped attachment the color of egg yolk. The petals surround the column, where the style, stigma, and stamens all coalesce. Epipactis gigantea is pollinated primarily by syrphid flies, but wasps are also regular pollinators. As is visible in the second photo, the plant attaches a pollinium to the back of the pollinator, and the latter proceeds to transport this valuable cargo about, finally unloading it in the welcoming grasp of another specimen.

Source:

van der Cingel, N.A. An Atlas of Orchid Pollination: America, Africa, Asia and Australia. Rotterdam: A.A. Balkema, 2001.