Foliose lichens at Kew occur across rocks, trees, and soil, forming leafy, lobed thalli that capture moisture and light efficiently. Their varied colours and textures reflect species diversity and microhabitat conditions. These lichens contribute to nutrient cycling, support small invertebrates, and signal clean, stable environmental conditions within the gardens today.

Fruticose lichens in Kew appear as upright tufts or graceful pendants across trees and stone surfaces. Their intricate branching forms reveal subtle environmental shifts. Because these lichens are highly sensitive to airborne pollutants, their presence and vitality offer valuable insight into Kew’s air quality, reflecting cleaner conditions where these delicate organisms can thrive.

Crustose lichens form thin, tightly adherent crusts on rocks, bark, and man-made surfaces. Their firmly attached structure makes them highly resistant to drought and exposure. These lichens contribute to rock weathering, stabilise surfaces, and serve as sensitive indicators of environmental change, especially long-term shifts in air quality and microhabitat conditions.