A tale of two parasites

Several weeks ago I talked about a fascinating plant parasite called Ghost Pipe. Here’s another, Indian Pipe, which derives nutrients from mycorrhizal fungi with which it is found. Although both of these plants belong to the same phylum, they occupy different plant orders. Ghost Plant belongs to a group which includes tea, blueberry, and azalea while Indian Pipe is a close relative of herbs such as mint, basil, and rosemary.

In a genealogical sense, these plants are only as closely related to each other as placental mammals are to marsupials. Although I cannot tell you how long ago their common ancestor may have lived, I am certain that it was photosynthetic and not an achlorophyllous parasite. So, parasitism evolved, independently and de novo, in each line. It is surely an effective way of making a living and there is every reason to expect the niche to have been exploited by species from vastly different groups. Plant form is constrained by the chemical and physical nature of life on this planet. That two, unrelated, forms should express the same solution to the complex question of survival is to be expected. It is simply an outcome of first principles.


12 thoughts on “A tale of two parasites

    • Oh my … the taxonomy and systematics of the fungi, especially of the mycorrhizae, is something I know nothing about L/E. It would be my guess that the answer is yes, however, and that very specific associations form between Monotropa uniflora (the plant, and this case) and one or few closely related species of fungus. It would appear that the mycorrhizae may be divided into several large groups and that these may be distinguished from one another based upon the very specific mechanism they employ to invade the host plant. And, yes, the fungal symbiont is required for survival. It is difficult if not impossible to move plants which form commensal or mutualistic associations unless an inoculum of the fungus is included.

  1. You can add beechdrops to the discussion as well. As they say, nature abhors a vacuum and therefore if there is a space to be exploited something will show up to do so. Ecologically I am still not sure where we fall in that concept…or at least how we left our purpose behind, if we ever had one.

    • Absolutely. One of Darwin’s favorite metaphors was that of the ‘wedge.’ He viewed all available niche space as a sphere … and each of the world’s organisms represented a wedge which fit nicely as part of the whole. All of the wedges ‘competed’ to maintain its position. If another species should arise, with favorable characteristics, it might be able to ‘wedge out’ one of its competitors to gain space in the sphere. So you see, you are exactly correct when you say that nature abhors a vacuum and that open space will always be exploited. As to the ecological function of our own species? I believe we developed (socially and culturally and technologically) way beyond that long ago. I do now know what we now represent. Thanks for chiming in.

      • We are like an appendix…unnecessary (in terms of Earth ecology) and we have exploded to spread our poison. We could offer a lot more but are too busy with ourselves.

  2. Astonishing that they are related to basil, mint and rosemary! No resemblance in structure or color! Do they have a smell? Would think they do if they are related to that trio of pungent herbs! I too like the desaturation!

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