ap·pres·so·ri·um 
(ăp′rə-sôrē-əm)
(ăp′rə-sôrē-əm)n. pl. ap·pres·so·ri·a (-sôrē-ə)
The flattened tip of a hypha in various species of parasitic fungi, from which a filament emerges that penetrates the host's tissues.
[New Latin appressōrium, from Latin appressus, past participle of apprimere, to press down; see APPRESSED.]