This is a list of species in the fruticose lichen genus Usnea, commonly known as "beard lichens". , Species Fungorum (in the Catalogue of Life) accepts 128 species of Usnea, although many more have been described throughout the genus's extensive taxonomic history. The fungal nomenclatural authority Index Fungorum lists nearly 2,000 taxa that have ever been associated with the genus, including forms, varieties, and subspecies, as well as numerous obsolete names, synonyms, misapplied names, and taxa temporarily placed in Usnea but later transferred to other genera. This significant discrepancy between accepted species and total published names reflects the complex taxonomic history of the genus. Ongoing revisions with molecular phylogenetics and morphological studies continue to refine the understanding of Usnea species boundaries.
A
Usnea acromelana Usnea alboverrucata Usnea amblyoclada Usnea angulata Usnea antarctica Usnea aranea Usnea articulata Usnea aurantiaciparvula Usnea austrocampestris – Falkland Islands
B Usnea barbata Usnea beckeri Usnea bismolliuscula Usnea boomiana Usnea brattiae
C Usnea cavernosa Usnea cedrosiana Usnea ceratina Usnea chaetophora Usnea cirrosa Usnea clerciana Usnea confusa Usnea cornuta Usnea crenulata Usnea crocata Usnea cylindrica
D Usnea diplotypus
E Usnea effusa Usnea elata Usnea elixii Usnea esperantiana Usnea exigua
F Usnea fibriloides – Argentina Usnea filipendula Usnea firmula Usnea flammea Usnea flavocardia Usnea flavorubescens Usnea fleigiae Usnea florida Usnea floriformis Usnea foveata Usnea fragilescens Usnea fulvoreagens
G Usnea galapagona – Galápagos Islands Usnea geissleriana Usnea glabrata Usnea glabrescens Usnea glauca Usnea grandisora Usnea grandispora
H Usnea himantodes Usnea hirta
I
Usnea inermis Usnea intermedia
K Usnea kalbiana Usnea krogiana
L Usnea lambii Usnea lapponica Usnea leana Usnea longiciliata Usnea lutii
M
Usnea macaronesica Usnea maculata Usnea marivelensis Usnea mayrhoferi – Galápagos Islands Usnea mekista Usnea messutiae Usnea molliuscula Usnea moreliana Usnea mutabilis Usnea myrmaiacaina
N Usnea neuropogonoides Usnea nidifica Usnea nidulifera
O Usnea oncodeoides Usnea oncodes Usnea oreophila – Brazil
P Usnea pacificana Usnea pallidocarpa Usnea parafloridana Usnea patriciana Usnea pendulina Usnea perplexans Usnea poliothrix Usnea praetervisa Usnea propagulifera Usnea pulvinata Usnea pycnoclada Usnea pygmoidea
Q Usnea quasirigida
R Usnea ramulosissima Usnea roseola Usnea rubicunda Usnea rubriglabrata Usnea rubrotincta
S
Usnea sanguinea Usnea saxidilatata Usnea scabrata Usnea scabrida Usnea silesiaca Usnea sphacelata Usnea subalpina Usnea subaranea Usnea subcapillaris Usnea subcomplecta – Galápagos Islands Usnea subcornuta Usnea subdasaea Usnea subeciliata Usnea subflammea Usnea subflaveola Usnea subfloridana Usnea subglabrata Usnea subparvula Usnea subrubicunda Usnea subscabrosa
T Usnea tamborensis Usnea taylorii Usnea torulosa Usnea trachycarpa
U Usnea ushuaiensis
V Usnea viktoriana Usnea vrieseana
W Usnea wasmuthii
X Usnea xanthopoga
References