Joined: Jan 2, 2020 Last Active: Jul 24, 2024 iNaturalist

Since 2017, I have been fortunate to be part of the Old Growth Forest Group in the Catskill Forest Preserve in southern New York State. My focus is on lichens in First Growth and Old Growth Forests.
Identifying Lichens from a photograph is extremely difficult because lichens are a confusing set of organisms.

A wet lichen species looks much different than the same dry lichen. When lichens are wet, the upper cortex adjusts to “sunlight transmission mode”. The wet upper cortex becomes more transparent allowing the sunlight to reach the green algae normally hidden within and start photosynthesis.

A sterile lichen looks much different than a fertile lichen. As they mature, the various lichen reproductive parts of the lichen become more and more pronounced. Soredia, Isidia, and Apothecia all become much more prevalent and greatly change the look of the lichen. When possible, I will attempt to show these various wet/dry, sterile/fertile conditions on an additional photo #2, to help in identification.

To make any accurate identification, a photo must be crisp and sharp. You need to be able to see as much of the organism as possible and also show the substrate. You need to see many fine details to help identify the lichen. This requires great depth of field in the photo, or a combination of two photos.

Lichens also tend to grow closely intermixed and almost every photograph of one lichen will have several other species present in the photo. To eliminate confusion, I spend a great deal of time carefully photoshopping other lichens out of the photo to show the actual identified species more clearly. In most cases, I will show enlarged details in an inset that will help with identification. This gives you both a wide-angle view of the whole organism, and a close up of the necessary identification details.

No matter how good the photo is, many lichens simply cannot be identified from a photograph. There are many species that are so similar in appearance that they need chemical tests, TLC, or even DNA testing to accurately separate into species. This requires that an actual physical sample be sent to a qualified testing facility.

Because collecting samples in State Parks and Preserves is not allowed, I needed special permits. I have received great support from NYS and NYC for lichen research in Southern New York and have been graciously granted collection permits from the NYS DEC, Department of Environmental Conservation, for Lichen samples collected in the NY State Forest Preserves. I have a special permit from the NYS OPRHP, the Office of Parks, Recreation and Historic Preservation, to allow me to collect Lichen samples from the NY State Parks. I also have a collection permit from the NY City DEP, the Department of Environmental Protection, to allow me to collect Lichen samples from the vast NYC Watershed land holdings near the upstate NYC reservoirs. These wonderful collection permits made this work possible.

Collecting the sample is only one step in the process. To be accurate to species level, I needed help from a qualified research lab to make many of the final identifications. I have been greatly assisted by two of the World’s Top Lichenologists, Dr. R. Troy McMullin at CMN in Ottawa, and by Dr. James C. Lendemer, formerly at the NY Botanical Garden in NYC, now at the NYS Museum in Albany, NY. These two Lichen experts made this work accurate!

Thanks to their help with determinations, most of the photographs I post here are of actual lichen samples that were accurately identified in a lab rather than just a guess from a photograph. Many of these specific observations are linked to the CNALH database for the actual tested physical sample and are therefore truly Research Grade.

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