I wasn't expecting to see many species in bloom on a trip this past weekend to the Merritt area of British Columbia, but a backwoods drive yielded a few late-blooming plants. Among the expected asters in bloom were a few of these pine-drops still in flower (spotted first by my friend), though most had gone to seed.

Plants of Pterospora andromedea can be found in western North America and northeastern North America, though in several of the northeastern US states, the species is listed as endangered or threatened, including New York. Once relatively common in New York, the reasons for its decline are apparently unknown. However, in western North America, it is a relatively common species (I've seen plants 3 or 4 times in the past couple years, in British Columbia, Washington and Oregon). The species is typically associated with dry to mesic coniferous or mixed forests. Plants grow to 1m (3.3ft) or more.

Pterospora andromedea is a parasite, and more specifically, it is a mycoheterotroph. Like Monotropa uniflora, plants of the species extract photosynthates (and most mineral nutrients) from an underground relationship with a fungus that has in turn gained its sugars from a nearby woody plant. In the case of Pterospora andromedea, the known fungal associates are members of the genus Rhizopogon. I was going to write that Pterospora andromedea is achlorophyllous (lacking chlorophyll), but that is incorrect: Cummings and Welschmeyer in "Pigment composition of putatively achlorophyllous angiosperms" determined that Pterospora andromedea does produce trace amounts of chlorophyll a.

Pterospora means "winged seed", a property evident in the photographs available on the Botanical Society of America site. The epithet andromedea is seemingly a reference to Andromeda of Greek myth, but a couple web sources give different reasons why; one refers to the flask shape of the flowers, another mentions the flower colouration.