Polychidium (Ach.) Gray
Thallus fruticose, heteromerous, greenish-blue to brownish, dichotomously branching, dendroid and often complex, thicker, secondary branches towards base, thinner, terete, anastomosing branches at apices, corticolous. Photobiont blue-green Nostoc or Scytonema. Apothecia red-brown, without a thalline margin. Ascospores 8 per ascus, colourless, polymorphic, ellipsoid to spindle-shaped, thin or thick-walled, 1- or 2- septate.
Polychidium, a genus of 5 described species is included in the family Peltigeraceae [Henssen Symb. bot. upsal. 18: 99-109 (1963)]. One species is recorded from New Zealand.
