The thallus consists of a thin-walled , tough , multinucleic cell with a diameter that ranges typically from 1 to 4 centimetres ( 0.39 to 1.57 in ) although it may achieve a diameter of up to 5.1 centimetres ( 2.0 in ) in rarer cases .
The diameter is usually from 1 to 4 centimetres ( 0.39 to 1.57 in ) although it may get to 5.1 centimetres ( 2.0 in ) in rare cases .