I’ve previously featured Monotropa uniflora on BPotD. This photograph is a good complement to the previous one, since it shows a more typical habitat – the plant pushing through the duff of a coniferous forest floor. Lotus also asked in the Flickr posting why the plants have a pinkish tone. Reading through some of the local field guides, I noted that this isn’t unusual; the colour of the plants is described as ranging from waxy-white to pinkish. However, I don’t have an answer to the question of variation. I can think of four possible reasons: soil pH, the fungal species it is associated with, genetic variability or the soil’s nutrient composition. It could be any or none of what I think it might be. Please feel free to suggest other ideas or, ideally, cite a scientific paper that has examined the question.