Ephebe species form dark brown-to-black mats of fine, hair-like filaments that creep across rock and bark surfaces like a tangled carpet. Each tuft is attached at a single point by a small
holdfast, then branches repeatedly to create an intricate web. Because the filaments lack a true outer skin (), the fungal threads, or
hyphae, lie directly on the surface; when young they surround the partner alga but later organise into a loose central strand. The algal associate is from the
cyanobacterial genus
Stigonema, which grows as bead-like chains of cells and gives the lichen its ability to
fix atmospheric nitrogen. Reproductive bodies begin as tiny flask-shaped structures called
pycnidia and mature into disc-shaped
apothecia that sit flush with the filament surface. The are minute pin-pricks, ringed by a true fungal rim but not by thallus tissue. Inside, the spore layer is jelly-like; its upper portion turns brown and reacts iodine-positive (blue-green) in chemical tests, a useful identification clue. Slender supporting threads (
paraphyses) line the cavity, their tips slightly swollen. Each spore sac (
ascus) is cylindrical to club-shaped, has a thin wall that
stains blue in iodine, and typically contains eight—but sometimes up to sixteen—colourless
ascospores. The spores lack cross-walls, though a few may show one or two "plasma bridges", internal strands that do not reach the wall.
Asexual spores (
conidia) are produced in the remaining pycnidia; they are simple, rod-to-oval bodies released from elongated, branched
conidiophores. No
secondary metabolites have been detected with
thin-layer chromatography, and standard
spot tests on the thallus are negative. ==Species==