reindeer moss: an erect greyish branching lichen of Arctic and even some north temperate regions constituting the chief food for reindeer and caribou and sometimes being eaten by humans
lichen: any thallophytic plant of the division Lichenes; occur as crusty patches or bushy growths on tree trunks or rocks or bare ground etc.
electronic equipment: equipment that involves the controlled conduction of electrons (especially in a gas or vacuum or semiconductor)