Oryza this subfamily are the arm cells and fusoid cells found in their leaves. One species, Asian rice ("O. sativa"), provides 20% of global grain and is a food crop of major global importance. The species are divided into two subgroups within the genus. Over 300 names have been proposed for species, subspecies, and other infraspecific taxa within the genus. Published sources disagree as to how many of these should be recognized as distinct species. The following follows the World Checklist maintained by Kew Garden in London. many species now regarded as better suited to other genera: "Echinochloa Leersia Maltebrunia Potamophila
Helitron (biology) Helitron (biology) Helitrons are one of the three groups of eukaryotic class 2 transposable elements (TEs) so far described. They are the eukaryotic rolling-circle transposable elements which are hypothesized to transpose by a rolling circle replication mechanism via a single-stranded DNA intermediate. They were first discovered in plants ("Arabidopsis thaliana" and "Oryza sativa") and in the nematode "Caenorhabditis elegans", and now they have been identified in a diverse range of species, from protists to mammals. Helitrons make up a substantial fraction of many genomes where non-autonomous elements frequently outnumber the putative autonomous partner. Helitrons seem to have a major role