Ecology

Unusual substrates

Lichens grow on a wide variety of substrates, both natural and man-made. Thousands of species grow on soil, rock or bark. These substrates are widespread and common, consequently they are the ones on which people are most likely to see lichens and many of the photos scattered through this website show lichens on those substrates. Unless there is a high level of pollution you will find various URBAN LICHENS on rock substitutes such as concrete, bitumen and brick and on bark substitutes such as wooden seats, poles or beams. Leaves in humid areas are host to several hundred species of FOLIICOLOUS LICHENS. This page is devoted to substrates other than those already mentioned.

A bleached kangaroo bone in bushland within the city of Canberra was host to this Xanthoria thallus . Also within Canberra, this Xanthoparmelia thallus (about two centimetres in diameter) grew on a sunshade fabric that is sold under the trade name Sarlon and Amandinea punctata grew on clear polycarbonate roofing over a patio.

Old metal is home to a variety of lichens. The most obvious lichens on the rusted metal in this dumped rubbish belong to the genus Xanthoparmelia and here is a closer view . The photo, below left, shows another Xanthoparmelia growing on a long-abandoned metal kettle. At Wallangarra on the border between Queensland and New South Wales there was a coloured metal fence with these eye-catching patterns . A closer look showed remnant fragments of lichen thalli on some of these patterns. So these discoloured areas are simply the ghosts of departed lichens! Given a few more years Usnea thalli might cover this street sign on Christmas Island in the Indian Ocean. The photos below on the right show well-developed Xanthoparmelia thalli growing on various plastic, metal and glass parts of a long-disused school bus. Lichens that grow on glass are called VITRICOLOUS LICHENS.

A number of thalli of a Xanthoria species are growing on the piece of old net (below left) made from a natural fibre. The discarded leather shoe (below right) was found alongside a road in central New South Wales. It is easy to see a greenish Xanthoparmelia thallus and several orange Caloplaca thalli, but there are at least four other species growing on the shoe. Here are a couple of closer views. This photo shows a colony of Thysanothecium sorediatum that had been growing on the cloth seat of an abandoned car in Cairncross State Forest, northeast New South Wales.

Xanthoria on a net made from a natural fibre. A 'lichenized' old leather shoe (right). (click to enlarge images)