The genus Agaricus in the Caribbean II. Refined phylogeny of Agaricus subg. Spissicaules with description of two new sections and eight new species

• Published in: Mycological progress Vol. 20; no. 4; pp. 381 - 411
• Main Authors: Ortiz-Santana, Beatriz, Chen, Jie, Parra, Luis A., Angelini, Claudio, Lodge, D. Jean, Kerrigan, Richard W., Callac, Philippe
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2021; Springer Nature B.V; Springer Verlag
• Subjects: Agaricus; Bayesian analysis; Biomedical and Life Sciences; Divergence; Ecology; Environmental Sciences; Life Sciences; Microbiology; New species; Original Article; Phylogenetics; Phylogeny; Plant Sciences; Species diversity; Species richness; Statistical inference; Caribbean area; Divergence times; ITS; Agaricaceae; Neotropics; Taxonomy; Multigene phylogeny; Agaricus; Caraibes; Bayesian Analyses
• ISSN: 1617-416X; 1861-8952
• DOI: 10.1007/s11557-021-01686-9

The genus
Agaricus
currently includes about 500 species in seven subgenera. Continuing an inventory of species in the Caribbean, this manuscript’s objective was to focus on those in
Agaricus
subg.
Spissicaules
. This subgenus has been recently proposed and divided into four sections by applying a new taxonomic system in which supraspecific taxa are ranked according to their divergence times. We similarly applied this system using Bayesian evolutionary analyses (BEAST). Phylogenetic analyses were performed using maximum likelihood and Bayesian inference methods, based either on multi-gene sequence data (ITS, ncLSU, and
TEF
1) or only on ITS, and including new collections from the Caribbean and one from Argentina. The analyses revealed seven major clades, all with divergence time estimated around 24 Ma. Among those, four were known sections of the subgenus, one remains a putative section, and we introduce the remaining two as new sections,
A.
sect.
Fulventes
and
A.
sect.
Globoterminales
. New samples were distributed among ten species-level clades. For eight of them, new species were proposed. They are distributed as follows:
A. nanofulvens
and
A. basicingulatus
are in the two new sections cited above, respectively;
A. ciferrianus
and
A. omphalodiscus
are in
A
. sect.
Subrutilescentes
;
A. baronii
,
A. furfuripes
,
A. microincrustatus
, and
A. parvisporus
are in
A.
sect.
Rarolentes
. The eight new species and the four sections to which they belong are described in detail. High levels of both species richness and phylogenetic diversity in the Caribbean region contributed to the refinement of the classification of
A.
subg.
Spissicaules
.