Bluestems, Lemon Grasses, Silvergrasses, and Allies

The Andropogoneae, sometimes called the sorghum tribe, are a large tribe of grasses (family Poaceae) with roughly 1,200 species in 90 genera, mainly distributed in tropical and subtropical areas. They include such important crops as maize (corn), sugarcane, and sorghum. All species in this tribe use C4 carbon fixation, which makes them competitive under warm, high-light conditions.

Andropogoneae is classified in supertribe Andropogonodae, together with its sister group Arundinelleae. Subdivisions include 12 subtribes, but the position of several genera within them is still unresolved (incertae sedis). Hybridisation was probably important in the evolution of the Andropogoneae, and the tribe's systematics are still not completely resolved. From the morphological point of view, the merging of the former subtribe 'Dimeriinae' (having solitary spikelets borne in 'robust' raceme rachis) into the subtribe Ischaeminae (having paired spikelets borne in 'fragile' raceme rachis) is doubtful. Affinities within the tribe are complex and still under investigation. Shahid Nawaz, a grass specialist at the Blatter Herbarium, is working on the phylogenomics of the tribe from India.

According to preliminary phytogeographic research on the tribe by M.S. Kiran Raj, Peninsular India, home to 54 genera (including nine endemic genera, viz., Bhidea, Lophopogon, Glyphochloa, Pogonachne, Trilobachne, Pseudodichanthium, Triplopogon, Nanooravia, and Manisuris) and roughly 500 species, is thought to be the primary or secondary centre of diversity for Andropogonoid grasses. About 40% of the representative taxa are exclusively endemic to peninsular India, with the highest species diversity and endemicity found in genera like Arthraxon, Chrysopogon, Cymbopogon, Dichanthium, Dimeria, Heteropogon, Ischaemum, Ophiorus, Sehima, and Themeda.