C₄ Carbon Fixation - Plants That Use C₄ Carbon Fixation

Plants That Use C₄ Carbon Fixation

About 7600 species of plants use C₄ carbon fixation, which represents about 3% of all terrestrial species of plants. All these 7600 species are angiosperms. C₄ carbon fixation is less common in dicots than in monocots, with only 4.5% of dicots using the C₄ pathway, compared to 40% of monocots. Despite this, only three families of monocots utilise C₄ carbon fixation compared to 15 dicot families. Of the monocot clades containing C₄ plants, the grass (Poaceae) species use the C₄ photosynthetic pathway most. Forty-six percent of grasses are C₄ and together account for 61% of C₄ species. These include the food crops maize, sugar cane, millet, and sorghum. Of the dicot clades containing C₄ species, the order Caryophyllales contains the most species. Of the families in the Caryophyllales, the Chenopodiaceae use C₄ carbon fixation the most, with 550 out of 1400 species using it. About 250 of the 1000 species of the related Amaranthaceae also use C₄.

Members of the sedge family Cyperaceae, and numerous families of Eudicots, including the daisies Asteraceae, cabbages Brassicaceae, and spurges Euphorbiaceae also use C₄.