Anaptychia palmulata is an easily recognized foliose lichen with distinctive lobules and that frequently produces apothecia. It was described more than two centuries ago, has been consistently recognized as a distinct species since that time, and is included in many published field guides. 

The species occurs throughout eastern North America and in southern Canada. Scattered occurrences have also been reported in North and Eastern Russia, China, and Eastern Asia (Tripp & Lendemer, 2020) (Brodo et al., 2001).

The EOO of Palmulata from 1862 until now is estimated to be 10,827,698 km², and it has not changed historically from 1925 until now, while the AOO was 4,072 km² and became 3,836 km² with a 6% decline. When comparing the difference between 1925-2024 (AOO: 3,836 km², EOO: 19,827,699 km², 1,560 observations) and from 1990-2024 (AOO: 2,328 km², EOO: 4,662,048 km², 859 observations), we have a decline in the AOO of 39% and EOO of 57%, while observations of mature adults decreased by 45%.

When measuring the population reduction over three generations according to A2(c), we observe a 39% decline in AOO, indicating vulnerability. This decline is attributed to the diminishing quality of habitat resulting from the reduction of old-growth forests (Boggess et al., 2024) (Tripp et al., 2020). Similarly, under A4(b), we’ve estimated a significant 46% decline in mature individuals over the past century, marking it as vulnerable. With an estimated count of 50 mature individuals per site, the geographical range, as determined by form B2 (area of occupancy), at 1,508 km², also indicates vulnerability.

The species is predominantly found in mature mixed hardwood or mixed hardwood-conifer forests, often at sites with large non-calcareous rock outcrops. It is frequently found on mature hardwood trees belonging to the genera Acer (maple), Aesculus (buckeye), Betula (birch), Fagus (beech), and Quercus (oak). The occurrence data suggest a strong preference for red oak (Quercus rubra). When growing on trees, it is predominantly found on the bark, particularly near the base of the trunks. It also grows on large, shaded non-calcareous outcrops and boulders of sandstone, schist and granitic rock types. When found on rocks it usually grows in mixed moss-lichen communities within forests close to the coast, in hilly forests influenced by maritime conditions, or in other areas with high humidity such as stream ravines and riparian corridors.

Anaptychia palmulata is predominantly found in areas of mature forest, making habitat degradation and fragmentation due to logging and urbanization, as well as other land use changes and habitat disturbance, primary threats to the species. Impacts from air pollution are also a threat. The species is not known to occur in highly degraded or young forest stands, or in urban areas

As Anaptychia palmulata grows in mature forests, conservation efforts should prioritize site and area protection, along with habitat preservation. These efforts should be supplemented by public education through awareness campaigns. Additionally, research and observation of this lichen species should be conducted to accurately document report detailed population demographics.

Studying population size, distribution, and trends is crucial for understanding the health and dynamics of ecosystems. It provides insights into species responses to environmental changes, helps identify areas in need of conservation attention, and informs management strategies to maintain biodiversity and ecosystem stability over time.

Few studies have reported on the biological activities and medicinal uses of Anaptychia palmulata.(Yamamoto et al., 2015) (Yamamoto et al., 2010)

n.d. A Cumulative Checklist for the Lichen-forming. https://www.ndsu.edu/pubweb/~esslinge/chcklst/chcklst7.htm.
n.d. Consortium of Lichen Herbaria. https://lichenportal.org/portal/taxa/index.php?taxon=Anaptychia+palmulata+&formsubmit=Search+Terms.
n.d. Lichensmartimes. http://www.lichensmaritimes.org/index.php?task=fiche&lichen=961&lang=en#:~:text=Rare taxon found on the,hilly forests under maritime influence. .
2024. NatureServe Explorer. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.123002/Anaptychia_palmulata.
n.d. The William and Lynda Steere herbarium. https://sweetgum.nybg.org/science/vh/specimen-details/?irn=4810683.
(Lendemer, Harris, & Tripp, 2013)
Tripp, Erin, and James Lendemer. 2020. Field Guide to the Lichens of Great Smoky Mountains National Park. Univ Tennessee Press; First Edition
Brodo, I. M.; Sharnoff, S. D.; Sharnoff, S.; Nature, C. M. O. Lichens of North America; Yale University Press, 2001.
Yamamoto, Yoshikazu & Takeda, Mizuki & Sato, Yoshitaka & Hara, Kojiro & Komine, Masashi & Inamoto, Tamio. (2010). Inhibitory effects of the extracts of natural thaili and cultured mycobionts of lichens against 15 bacteria. Lichenology. 9. 11-17.
Yamamoto, Y., Hara, K., Kawakami, H., Komine, M. (2015). Lichen Substances and Their Biological Activities. In: Upreti, D., Divakar, P., Shukla, V., Bajpai, R. (eds) Recent Advances in Lichenology. Springer, New Delhi. https://doi.org/10.1007/978-81-322-2235-4_10