LICHEN n.
One of a class of cellular, flowerless plants, (technically called Lichenes), having no distinction of leaf and stem, usually of scaly, expanded, frond-like forms, but sometimes erect or pendulous and variously branched. They derive their nourishment from the air, and generate by means of spores. The species are very w…
NOTATION n.
haracters, symbols, or abbreviated expressions used in art or science, to express briefly technical facts, quantities, etc. Esp., the system of figures, letters, and signs used in arithmetic and algebra to express number, quantity, or operations.