5/13/ 2012 12:30 University of Washington Lichen Observations

Walking to class at the University of Washington students pass probably an average of 5-10 lichen. Along memorial way several can be observed. It is very difficult to identify and distinguish between particular species, but from my observations I believe all the species listed below can be found along memorial way alone.

Scoliciosporum sarothamni AKA Vezda or Vainio: found on the trunk of nearly every tree along memorial way, soft to touch, grows in large patches (3-18 ft)
• gray to light green dust lichen
• dust lichens are closely attached, composed of tiny powdery granules, most don’t produce fruiting bodies- instead spread the powdery granules
• grows well in polluted areas
• usually found on bark, but occasionally rock. prefers smooth bark

Candelaria concolor: found on about a third of the trees along memorial way, generally growing in smaller patches (1/2 inch- 1 ft)
• Yellow to bright green and powdery
• Grows on branches and shrubs
• Looks like it is crustose, but it actually has rhizines so it’s foliose
• One of the most common small foliose lichens
• Relatively tolerant of pollution
• Common in coastal regions, especially in Hawaii
• Environment Hamilton is training high school students to use this lichen to monitor air pollution in neighborhoods by measuring the density and distribution over time

Evernia prunastri: found growing on about ¼ of the trees along memorial way, generally higher up on the tree, in very small clumps
• AKA Antlered Perfume or oakmoss
• mountainous temperate regions in NA and across S. central Europe
• Elongated lobes
• Long/ dangly 1-4 mm wide and up to almost a foot long
• Divergently branches
• Light green
• Soft
• On trees (deciduous and coniferous), shrubs, mostly lower elevations
• Looks and is closely related to spruce moss but that is generally more white
• Commercially harvested for perfume in Europe and sent to France
• Has been used since 16th century to make perfumes, helps the fragrance stay place
• Grows slowly despite it’s name meaning “sprouting well”

Parmelia sulcata: covers nearly every tree on memorial way
• AKA shield lichen
• One of the most common in North America
• Used in dying wool
• Loose larger leaved
• 1-3 mm wide
• Pale grey top, black underneath
• Soredia (use for reproduction) in cracks
• Grows on trees and sometimes rocks, mostly open areas
• Likes shade
• Hummingbirds like to use in nest building
• Spreads to California and Arizona

Some interesting facts about lichen:
• Fungi gives lichen its shape
• Can live in all different kids of habitats
• Dry lichen can absorb water super fast- 3-35 times its weight in seconds, also dry out slowly
• Obtain most their water and nutrients from the air- so they respond dramatically to air quality
• Metals, gasses, and acid all effect lichens
• You can detect how stressed lichens are by the number of their reproductive structures
• Surface lichen grows on is called substrate
• 1,000 known species in the Pacific Northwest, 3,600 in the United States and over 25,000 worldwide.
• Pioneer species- so they are the first on newly cleared areas
• Some are N fixers
• Lichens also produce an arsenal of more than 500 unique biochemical compounds. Some of these are used by humans in medicines, perfumes, and dyes.- they also serve to keep away predators and competitors and control light exposure
• Lichen tolerance decreases with complexity
• Crustose are the little dust like kinds- they are very tolerant to changes in air chemistry
• Foliose are next most complex, so somewhat tolerant
• Fruticose are generally the least tolerant
• Lichen diversity is highest in the most pristine habitats
• Certain lichen species grow primarily (or even exclusively) in undisturbed habitats. Pseudocyphellaria rainierensis, for instance, grows in the old-growth coniferous forests of the Pacific Northwest.
• Lichens are used in air quality studies and research
• If there are factories or other large polluters it will be difficult to find lichen downwind from them
• Deer, elk, caribou, and birds eat lichen