You might wonder why this post is categorized as both success and failure. Let me begin with the success. When I started my jar designated to Myanmar in mid-August 2021, I placed a short rhizome cutting of P. nummulariifolia along the border of the substrate. Now, almost a year later, it is well established and seems to be coping very well with the conditions offered. It extends its rhizomes into different directions to explore the environment. Some characteristics of this Pyrrosia can be seen on the picture below. It produces fertile fronds that differ a lot in shape and size from the infertile fronds, and the fronds are covered with fine stellate hair (Patnaik 1963).
And the downside? I do not think that the death of Actiniopteris radiata, visible as a dry skeleton in the background, has to do with the expansion of P. nummulariifolia. However, my forecast is that the fern will be overgrowing the entire jar with its speed and vitality, if not controlled. Thus, my learning so far is to combine P. nummulariifolia in a next attempt only with plants that match its speed of expansion. That the lithophytic or epiphytic fern can become a problem for its host plants has been observed before:
“[…] Pyrrosia nummulariifolia (Sw.) Ching has also been studied in its natural habitat and is seen growing gregariously on the host plant with its wiry wide-creeping rhizome. It almost covers all the branches, twigs and even the leaves of very big trees like Ficus benghalensis etc. and is supposed to be one of the agents in causing epiphytosis in the host plant (cf. Ruinen 1953).” (Patnaik 1963)
Hermetospheres 
One response to “Pyrrosia nummulariifolia”
Keeping the balance to ensure that species can survive together is clearly a chalenge in a small environment, amazing to see but also to realize that at a larger scale there is always a continous change and what is an optimal balance? Plants that are fast growing with plants that are fast growing, and plants that are slow growing with plants that are slow growing. Facinating to have a playroom to try these things out. Amazed at your observations Herbie. A true naturalist!
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