About 8,100 plant species use  carbon fixation, which represents about 3% of all terrestrial species of plants. All these 8,100 species are angiosperms.  carbon fixation is more common in monocots compared with dicots, with 40% of monocots using the  pathway, compared with only 4.5% of dicots. Despite this, only three families of monocots use  carbon fixation compared to 15 dicot families. Of the monocot clades containing  plants, the grass (Poaceae) species use the  photosynthetic pathway most. 46% of grasses are  and together account for 61% of  species.  has arisen independently in the grass family some twenty or more times, in various subfamilies, tribes, and genera, including the Andropogoneae tribe which contains the food crops maize, sugar cane, and sorghum. Various kinds of millet are also . Of the dicot clades containing  species, the order Caryophyllales contains the most species. Of the families in the Caryophyllales, the Chenopodiaceae use  carbon fixation the most, with 550 out of 1,400 species using it. About 250 of the 1,000 species of the related Amaranthaceae also use .
Members of the sedge family Cyperaceae, and members of numerous families of eudicots – including Asteraceae (the daisy family), Brassicaceae (the cabbage family), and Euphorbiaceae (the spurge family) – also use .
No large trees (above 15 m in height) use , however a number of small trees or shrubs smaller than 10 m exist which do: six species of Euphorbiaceae all native to Hawaii and two species of Amaranthaceae growing in deserts of the Middle-East and Asia.