An 'appressorium' is a flattened,
hyphal "pressing" organ, from which a minute infection peg grows and enters the host, using
turgor pressure capable of punching through even
mylar.
Fungi that exhibit appressorial formation include the
necrotroph ''
Pyrenophora teres''.
References
★ C.J. Alexopolous, Charles W. Mims, M. Blackwell et al., ''Introductory Mycology, 4
th ed.'' (John Wiley and Sons, Hoboken NJ, 2004) ISBN 0-471-52229-5