We conducted a molecular phylogenetic study of the subfamily Chloridoideae using six
plastid DNA sequences (ndhA intron, ndhF, rps16-trnK, rps16 intron, rps3, and rpl32-trnL)
and a single nuclear ITS DNA sequence. Our large original data set includes 246 species
(17.3%) representing 95 genera (66%) of the grasses currently placed in the Chloridoideae.
The maximum likelihood and Bayesian analysis of DNA sequences provides strong support
for the monophyly of the Chloridoideae; followed by, in order of divergence: a Triraphideae
clade with Neyraudia sister to Triraphis; an Eragrostideae clade with the Cotteinae
(includes Cottea and Enneapogon) sister to the Uniolinae (includes Entoplocamia, Tetrachne,
and Uniola), and a terminal Eragrostidinae clade of Ectrosia, Harpachne, and Psammagrostis
embedded in a polyphyletic Eragrostis; a Zoysieae clade with Urochondra sister to
a Zoysiinae (Zoysia) clade, and a terminal Sporobolinae clade that includes Spartina,
Calamovilfa, Pogoneura, and Crypsis embedded in a polyphyletic Sporobolus; and a very
large terminal Cynodonteae clade that includes 13 monophyletic subtribes. The Cynodonteae
includes, in alphabetical order: Aeluropodinae (Aeluropus); Boutelouinae (Bouteloua);
Eleusininae (includes Apochiton, Astrebla with Schoenefeldia embedded, Austrochloris,
Brachyachne, Chloris, Cynodon with Brachyachne embedded in part, Eleusine, Enteropogon
with Eustachys embedded in part, Eustachys, Chrysochloa, Coelachyrum, Leptochloa with
Dinebra embedded, Lepturus, Lintonia, Microchloa, Saugetia, Schoenefeldia, Sclerodactylon,
Tetrapogon, and Trichloris); Hilariinae (Hilaria); Monanthochloinae (includes Distichlis,
Monanthochloe, and Reederochloa); Muhlenbergiinae (Muhlenbergia with Aegopogon, Bealia,
Blepharoneuron, Chaboissaea, Lycurus, Pereilema, Redfieldia, Schaffnerella, and Schedonnardus
all embedded); Orcuttiinae (includes Orcuttia and Tuctoria); Pappophorinae (includes
Neesiochloa and Pappophorum); Scleropogoninae (includes Blepharidachne, Dasyochloa,
Erioneuron, Munroa, Scleropogon, and Swallenia); Traginae (Tragus with Monelytrum,
Polevansia, and Willkommia all embedded); Tridentinae (includes Gouinia, Tridens,
Triplasis, and Vaseyochloa); Triodiinae (Triodia); and the Tripogoninae (Melanocenchris
and Tripogon with Eragrostiella embedded). In our study the Cynodonteae still include
19 genera and the Zoysieae include a single genus that are not yet placed in a subtribe.
The tribe Triraphideae and the subtribe Aeluropodinae are newly treated at that rank.
We propose a new tribal and subtribal classification for all known genera in the Chloridoideae.
The subfamily might have originated in Africa and/or Asia since the basal lineage,
the Triraphideae, includes species with African and Asian distribution.
Published by Elsevier Inc.