Mealy pixie cup is common on soils near rotting logs. Its fruiting structures are tiny goblets that are coated with a mealy, granular substance. Like others in its genus, the main body of this lichen is a patch of pale green scale-like squamules that grow across the soil around it.
Mealy pixie cup has upright, stalked reproductive structures (podetia) in the form of tiny, pale brownish-green or gray-green goblets. These are coated on the stalks and inside the cup with a granular, mealy texture — these are soredia, tiny granules of the lichen that can break off and begin new lichens elsewhere. Older podetia may appear bare, having shed most of their granules.
Mealy pixie cup is considered a fruticose lichen, meaning it is three-dimensional as opposed to flat or crusty. Like other cladoniform lichens (members of genus Cladonia), the thallus (main body) is a patch of pale green, scale-like squamules. Cladoniform lichens have a variety of reproductive structures, including clubs with colored tips, tiny goblets, horns, or shrubby branching structures.
A lichen is an organism that results when a fungus species and an algae species join together. Although the relationship between the fungi and algae is quite intimate and integrated, the lichen that is formed does not much resemble either of the components. Learn more about lichens on their group page.
Similar species
Missouri has about 37 species in genus Cladonia, most of which, at some point in their life cycle, exist as patches of unspectacular greenish or grayish, scalelike squamules. The various shapes, colors, and textures of the fruiting bodies are important for identification in this group. Mealy pixie cup is not the only species that produces cup- or goblet-shaped podetia.
Pebbled pixie cup (Cladonia pyxidata) is also common. It is quite similar, except that the inside of the cup has circular, flattened squamules (leaflike structures that can break off and start new lichens elsewhere), which are often greener than the rest of the cup. They look almost like little eggs in a nest. Also unlike the mealy pixie cup, the podetia are not coated with granular soredia, so they do not appear mealy.
There are other Missouri pixie cup species that look quite similar, including Gray’s cup lichen (C. grayi). Specialists use chemical tests for precise identifications.
Height: The cup-shaped podetia usually only reach about ½ inch tall. Cladoniform lichens, as they spread, may cover several square inches of substrate.
Statewide.
Habitat and Conservation
Mealy pixie cup grows on soil, usually near rotting wood, at the bases of trees, old rotting logs, or rocks. This species is found worldwide.
Fruticose lichens are some of the first to disappear when a natural habitat is disrupted.
Life Cycle
Lichens can reproduce vegetatively or sexually. Vegetative (asexual) reproduction occurs when a piece of a lichen’s thallus (main body) breaks away and begins growing independently elsewhere.
- The thallus of cladonia species is usually a patch of green scale-like squamules covering a small area of substrate, much like a little carpet of moss. These may easily be dislodged and moved elsewhere.
Another common form of vegetative reproduction is by soredia, which are small, granular packets of the fungus and algae. As a group, these usually look granular or mealy on the outer surface of a lichen.
- Mealy pixie cup’s goblets are covered with soredia. These are readily shed and can start new lichens elsewhere.
The fungal component of a lichen can reproduce sexually, in the same manner as other fungi: spores are created as the result of a fusion of gametes (sperm and ova) that occurs in reproductive structures of the fungus. The spores develop in, and are released from, a mushroom-like structure.
- In the case of mealy pixie cup, these structures are uncommon. When they occur, they look a lot like the podetia of a lichen called brown cap (or turban lichen, Cladonia peziziformis): upright stalks bearing ball-like, spore-shedding, brown knobs.
Human Connections
Mealy pixie cup is a joy to any photographer with a macro lens.
The Dutch graphic artist M. C. Escher created illustrations of geometrically impossible objects, such as infinite staircases, reflections on curved surfaces, and other mind-boggling subjects. In his famous piece “Waterfall,” he carefully drew fruticose lichens, with their branching knobby podetia and pixie goblets, as the trees and shrubs in his imaginary landscape.
Ecosystem Connections
Soil-living lichens are important stabilizers, preventing soil from being washed away by rain or blown by the wind.
Mealy pixie cup and other lichens and mosses that live at the bases of rotting logs tend to retain moisture, and they trap and collect soil and organic detritus, which encourages the decomposition of the wood.
Mosses, liverworts, hornworts, and lichens seem rather similar, but these organisms are in very different groups. Mosses, liverworts, and hornworts are small, low plants usually found in damp habitats. Unlike more familiar plants, they lack veinlike structures and do not produce flowers or seeds — instead, they produce spores. Meanwhile, lichens are not plants at all: they are a collection of different fungi that have photosynthetic algae living within their tissues.