Chloridoideae is one of the largest subfamilies of grasses, with roughly 150 genera and 1,600 species, mainly found in arid tropical or subtropical grasslands. Within the PACMAD clade, their sister group is the Danthonioideae.[1] The subfamily includes widespread weeds such as Bermuda grass (Cynodon dactylon) or goosegrass (Eleusine indica), but also millet species grown in some tropical regions, namely finger millet (Eleusine coracana) and teff (Eragrostis tef).

With the exception of some species in Ellisochloa and Eleusine indica, most of the subfamily's species use the C4 photosynthetic pathway. The first evolutionary transition from C3 to C4 photosynthesis in the grasses probably occurred in this subfamily, around 32 to 25 million years ago in the Oligocene.[2]

Phylogeny

Relationships of tribes in the Chloridoideae according to a 2017 phylogenetic classification, also showing the Danthonioideae as sister group:[3]

Danthonioideae

Chloridoideae

The following genera have not been assigned to a tribe:[3]

References

  1. ^ Soreng, Robert J.; Peterson, Paul M.; Romschenko, Konstantin; Davidse, Gerrit; Zuloaga, Fernando O.; Judziewicz, Emmet J.; Filgueiras, Tarciso S.; Davis, Jerrold I.; Morrone, Osvaldo (2015). "A worldwide phylogenetic classification of the Poaceae (Gramineae)". Journal of Systematics and Evolution. 53 (2): 117–137. doi:10.1111/jse.12150. hdl:11336/25248. ISSN 1674-4918. Open access icon
  2. ^ Christin, Pascal-Antoine; Besnard, Guillaume; Samaritani, Emanuela; Duvall, Melvin R.; Hodkinson, Trevor R.; Savolainen, Vincent; Salamin, Nicolas (2008). "Oligocene CO2 Decline Promoted C4 Photosynthesis in Grasses". Current Biology. 18 (1): 37–43. doi:10.1016/j.cub.2007.11.058. hdl:2262/82791. ISSN 0960-9822. PMID 18160293. Open access icon
  3. ^ a b Soreng, Robert J.; Peterson, Paul M.; Romaschenko, Konstantin; Davidse, Gerrit; Teisher, Jordan K.; Clark, Lynn G.; Barberá, Patricia; Gillespie, Lynn J.; Zuloaga, Fernando O. (2017). "A worldwide phylogenetic classification of the Poaceae (Gramineae) II: An update and a comparison of two 2015 classifications". Journal of Systematics and Evolution. 55 (4): 259–290. doi:10.1111/jse.12262. hdl:10261/240149. ISSN 1674-4918.
  • Media related to Chloridoideae at Wikimedia Commons
  • Data related to Chloridoideae at Wikispecies