Is there a possibility that the vascular bundles of early vascular plants are the mycelium of early fungi?

What is the process from algae to lichen to moss to fern? ? ?


In the strictest sense, anything is possible, in that we can never entirely rule out the possibility of shortcomings in our evidence and logic, and these are good questions to examine. This hypothesis, however, seems to both need significant clarification, and to be founded in misunderstandings. For example, structural and genetic evidence would seem to rule out the possibility that the vasculature of vascular plants are derived from mycelia. We have no reason to suspect that lichens evolved into mosses, or that mosses evolved into ferns. These are different branches on the tree of life, not different stages of the same lineage. One key thing to understand about the complexity and diversity of life is that what we see now is the result of billions of years of change, often quite slow, occasionally, through happenstance and circumstance, amazingly rapid.
If you want a technical description of the evolutionary process that led to plant vasculature, one starting point is:


On the subject of lichens, they are kind of off doing their own thing, not really plants at all.

Lichens are what happens when fungi and algae form a symbiotic relationship, and the bulk of each individual is made up the the fungal component. As a result they are often more aligned with fungi than plants.

The relationship between the fungal and algal portions of a lichen are thought to be a bit like the ancestral relationship between the organisms that contributed to the cell and the mitochondria, or to plants and the ancestral organisms that facilitated photosynthesis.

Regarding the plants and mycelium idea, dlevitis is correct. In addition, mycelia has characteristic hyphae structures that do not appear in fossilized plant vascular tissue.

Evolution is not a linear process, it’s a bush that is sometimes crosslinked back into itself. Algae, moss, ferns, etc all represent different branches that evolution took, and are not necessarily ancestral to each other in a line like you appear to be imagining. Algae, often (not always though) being single celled organisms, has more of an opportunity to form intimate and cryptic relationships with other branches of life (eg. to very much oversimplify, fungi + algae leading to liches, or animals + algae leading to coral).

It’s also important to keep in mind that everything that’s alive today has had equal time to evolve along its lineage. There isn’t anything that’s ‘more primitive’ in the way people often think of ‘primitive’, everything currently alive is equally well evolved.


I don’t think currently that is the way science looks at lichens, fungi catch algae that are ok free living, and then take their resources, so it’s not a symbiosis in a strict way.

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The individual species that make up a lichen can be free-living if seperated, but they bear no resemblance to the lichen when they’re grown independently.

The lichen specifically is considered to be a symbiotic organism as it is a specific and unique association resulting in a distinct, repeatable form. Symbiotic is generally how they’re referred to in scientific literature, but there are still a lot of specific details to learn.

Here’s a pretty typical example of the type language used:

This review addresses opportunities for expanding current knowledge on signalling and metabolic interplays in the lichen symbiosis using the tools and approaches of systems biology, particularly network modelling. The largely unexplored nature of symbiont recognition and metabolic interdependency in lichens could benefit from applying a holistic approach to understand underlying molecular mechanisms and processes.


Thank you for your answer and sharing!

I have no professional research in this area. From the structure of lichens, plant symbionts and some phenomena of gut microbes, I came up with this hypothesis.

Many studies have shown that fungi and plants cooperate closely underground, so I am also thinking about whether the above-ground parts are also related.

Most lichens are mycelium encasing the algae, so what about the reverse, what if the algae or other plant cells are encasing the fungus, is how I think about it.

The intestinal symbiosis found in many animals reminds me of what’s going on inside the vascular bundles of plants

Exploring the diverse, intimate lives of plants

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Or, if The original vascular bundles were not made of fungi, I wondered if fungi were involved in this matter. Is it possible that early plants formed vascular bundles to deal with fungi that invaded inside, and then this structure promoted the evolution of plants. ?

Vascular system is an adaptation to life out of water, so why do you think fungi had affected that?

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That seems extremely unlikely. There isn’t anything in the structures, the evolutionary history, or current fungal/plant relationships that we know of to suggest anything ofthe sort.

The structures appear to be 100% a plant evolution and to be (at least in part) a result of the evolution of roots and the need to transport water and nutrients around the rest of the plant.

Here’s an Into to Bio page that discusses this a bit in clear, non-technical language.

If you want a more technical and less general paper, the following is a decent start:

Make sure to read the references and dig up those papers to read as well.


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