آپرسوریوم

thumb|right|260px|Germinating Conidium|conidiospores of [[Hyaloperonospora parasitica. Observe the appressorium on top right.]] An appressorium is a specialized cell typical of many fungal plant pathogens that is used to infect host plants. It 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.