Hypha

Hypha, an elongated cylindrical filamentous structure, either unsegmented (unicellular) or segmented (multicellular), branched or unbranched and increasing by apical growth, which occurs in some algae and most fungi. Whether segmented or not, a hypha generally contains many nuclei. Loops frequently unite distinct threads, and clamp-connections, by a protuberance extending backwards at a transverse wall and joining the next cell, also occur. Fungal mycelium or "spawn" commonly consists of much branched unsegmented hyphee; and the so-called "compound thallus" of the larger fungi is made up of numerous multicellular hyphee, either densely interwoven into a felt (tela contcxta) or parallel and firmly adherent. They then so resemble parenchymatous tissue, the result of cell-division, as to be called pseudo-parenchyma.