hyphae

n. thread-like structure in fungi (Botany)

A hypha (plural hyphae) is a long, branching filamentous cell of a fungus, and also of unrelated Actinobacteria. In fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. A hypha consists of one or more cells surrounded by a tubular cell wall. In most fungi, hyphae are divided into cells by internal cross-walls called septa (singular septum). Septa are usually perforated by pores large enough for ribosomes, mitochondria and sometimes nuclei to flow among cells. The structural polymer in fungal cell walls is typically chitin (in contrast plants have cellulosic cell walls, and animal cells lack walls). Some Fungi however, have non septate hypha, meaning their hypha are not separated by septa.
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(n. pl.)
The long, branching filaments of which the mycelium (and the greater part of the plant) of a fungus is formed. They are also found enveloping the gonidia of lichens, making up a large part of their structure.
  

Noun
1. any of the threadlike filaments forming the mycelium of a fungus
(hypernym) fibril, filament, strand
(hyponym) conidiophore
(part-holonym) mycelium