<P> CAM has evolved convergently many times . It occurs in 16,000 species (about 7% of plants), belonging to over 300 genera and around 40 families, but this is thought to be a considerable underestimate . It is found in quillworts (relatives of club mosses), in ferns, and in Gnetopsida, but the great majority of plants using CAM are angiosperms (flowering plants). </P> <P> The following list summarizes the taxonomic distribution of plants with CAM: </P> <Table> <Tr> <Th> Division </Th> <Th> Class / Angiosperm group </Th> <Th> Order </Th> <Th> Family </Th> <Th> Plant Type </Th> <Th> Clade involved </Th> </Tr> <Tr> <Td> Lycopodiophyta </Td> <Td> Isoetopsida </Td> <Td> Isoetales </Td> <Td> Isoetaceae </Td> <Td> hydrophyte </Td> <Td> Isoetes (the sole genus of class Isoetopsida) - I. howellii (seasonally submerged), I. macrospora, I. bolanderi, I. engelmanni, I. lacustris, I. sinensis, I. storkii, I. kirkii </Td> </Tr> <Tr> <Td> Pteridophyta </Td> <Td> Polypodiopsida </Td> <Td> Polypodiales </Td> <Td> Polypodiaceae </Td> <Td> epiphyte, lithophyte </Td> <Td> CAM is recorded from Microsorium, Platycerium and Polypodium, Pyrrosia and Drymoglossum and Microgramma </Td> </Tr> <Tr> <Td> </Td> <Td> Pteridopsida </Td> <Td> Polypodiales </Td> <Td> Pteridaceae </Td> <Td> epiphyte </Td> <Td> Vittaria <P> Anetium citrifolium </P> </Td> </Tr> <Tr> <Td> Cycadophyta </Td> <Td> Cycadopsida </Td> <Td> Cycadales </Td> <Td> Zamiaceae </Td> <Td> </Td> <Td> Dioon edule </Td> </Tr> <Tr> <Td> Pinophyta </Td> <Td> Gnetopsida </Td> <Td> Welwitschiales </Td> <Td> Welwitschiaceae </Td> <Td> xerophyte </Td> <Td> Welwitschia mirabilis (the sole species of the order Welwitschiales) </Td> </Tr> <Tr> <Td> Magnoliophyta </Td> <Td> magnoliids </Td> <Td> Magnoliales </Td> <Td> Piperaceae </Td> <Td> epiphyte </Td> <Td> Peperomia camptotricha </Td> </Tr> <Tr> <Td> </Td> <Td> eudicots </Td> <Td> Caryophyllales </Td> <Td> Aizoaceae </Td> <Td> xerophyte </Td> <Td> widespread in the family; Mesembryanthemum crystallinum is a rare instance of an halophyte that displays CAM </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Cactaceae </Td> <Td> xerophyte </Td> <Td> Almost all cacti have obligate Crassulacean Acid Metabolism in their stems; the few cacti with leaves may have C Metabolism in those leaves; seedlings have C Metabolism . </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Portulacaceae </Td> <Td> xerophyte </Td> <Td> recorded in approximately half of the genera (note: Portulacaceae is paraphyletic with respect to Cactaceae and Didiereaceae) </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Didiereaceae </Td> <Td> xerophyte </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Saxifragales </Td> <Td> Crassulaceae </Td> <Td> hydrophyte, xerophyte, lithophyte </Td> <Td> CAM is widespread in the family </Td> </Tr> <Tr> <Td> </Td> <Td> eudicots (rosids) </Td> <Td> Vitales </Td> <Td> Vitaceae </Td> <Td> </Td> <Td> Cissus, Cyphostemma </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Malpighiales </Td> <Td> Clusiaceae </Td> <Td> hemiepiphyte </Td> <Td> Clusia </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Euphorbiaceae </Td> <Td> </Td> <Td> CAM is found is some species of Euphorbia including some formerly placed in the sunk genera Monadenium, Pedilanthus and Synadenium . C4 photosynthesis is also found in Euphorbia (subgenus Chamaesyce). </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Passifloraceae </Td> <Td> xerophyte </Td> <Td> Adenia </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Geraniales </Td> <Td> Geraniaceae </Td> <Td> </Td> <Td> CAM is found in some succulent species of Pelargonium, and is also reported from Geranium pratense </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Cucurbitales </Td> <Td> Cucurbitaceae </Td> <Td> </Td> <Td> Xerosicyos danguyi, Dendrosicyos socotrana, Momordica </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Celastrales </Td> <Td> Celastraceae </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Oxalidales </Td> <Td> Oxalidaceae </Td> <Td> </Td> <Td> Oxalis carnosa var . hirta </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Brassicales </Td> <Td> Moringaceae </Td> <Td> </Td> <Td> Moringa </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Salvadoraceae </Td> <Td> </Td> <Td> CAM is found in Salvadora persica . Salvadoraceae were previously placed in order Celastrales, but are now placed in Brassicales . </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Sapindales </Td> <Td> Sapindaceae </Td> <Td> </Td> <Td> Dodonaea viscosa </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Fabales </Td> <Td> Fabaceae </Td> <Td> </Td> <Td> CAM is found in Prosopis juliflora (listed under the family Salvadoraceae in Sayed's (2001) table,) but is currently in the family Fabaceae (Leguminosae) according to The Plant List). </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Zygophyllaceae </Td> <Td> </Td> <Td> Zygophyllum </Td> </Tr> <Tr> <Td> </Td> <Td> eudicots (asterids) </Td> <Td> Ericales </Td> <Td> Ebenaceae </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Solanales </Td> <Td> Convolvulaceae </Td> <Td> </Td> <Td> Ipomoea (Some species of Ipomoea are C3 - a citation is needed here .) </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Gentianales </Td> <Td> Rubiaceae </Td> <Td> epiphyte </Td> <Td> Hydnophytum and Myrmecodia </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Apocynaceae </Td> <Td> </Td> <Td> CAM is found in subfamily Asclepidioideae (Hoya, Dischidia, Ceropegia, Stapelia, Caralluma negevensis, Frerea indica, Adenium, Huernia), and also in Carissa and Akocanthera </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Lamiales </Td> <Td> Gesneriaceae </Td> <Td> epiphyte </Td> <Td> CAM was found Codonanthe crassifolia, but not in 3 other genera </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Lamiaceae </Td> <Td> </Td> <Td> Plectranthus marrubioides, Coleus </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Plantaginaceae </Td> <Td> hydrophyte </Td> <Td> Littorella uniflora </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Apiales </Td> <Td> Apiaceae </Td> <Td> hydrophyte </Td> <Td> Lilaeopsis lacustris </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Asterales </Td> <Td> Asteraceae </Td> <Td> </Td> <Td> some species of Senecio </Td> </Tr> <Tr> <Td> Magnoliophyta </Td> <Td> monocots </Td> <Td> Alismatales </Td> <Td> Hydrocharitaceae </Td> <Td> hydrophyte </Td> <Td> Hydrilla, Vallisneria </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Alismataceae </Td> <Td> hydrophyte </Td> <Td> Sagittaria </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Araceae </Td> <Td> </Td> <Td> Zamioculcas zamiifolia is the only CAM plant in Araceae, and the only non-aquatic CAM plant in Alismatales </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Poales </Td> <Td> Bromeliaceae </Td> <Td> epiphyte </Td> <Td> Bromelioideae (91%), Puya (24%), Dyckia and related genera (all), Hechtia (all), Tillandsia (many) </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Cyperaceae </Td> <Td> hydrophyte </Td> <Td> Scirpus, Eleocharis </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Asparagales </Td> <Td> Orchidaceae </Td> <Td> epiphyte </Td> <Td> Orchidaceae has more CAM species than any other family (CAM Orchids) </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Agavaceae </Td> <Td> xerophyte </Td> <Td> Agave, Hesperaloe, Yucca and Polianthes </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Asphodelaceae </Td> <Td> xerophyte </Td> <Td> Aloe, Gasteria, and Haworthia </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> </Td> <Td> Ruscaceae </Td> <Td> </Td> <Td> Sansevieria (This genus is listed under the family Dracaenaceae in Sayed's (2001) table, but currently in the family Asparagaceae according to The Plant List), Dracaena </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td> Commelinales </Td> <Td> Commelinaceae </Td> <Td> </Td> <Td> Callisia, Tradescantia, Tripogandra </Td> </Tr> </Table> <Tr> <Th> Division </Th> <Th> Class / Angiosperm group </Th> <Th> Order </Th> <Th> Family </Th> <Th> Plant Type </Th> <Th> Clade involved </Th> </Tr>

Where do the day and night photosynthesis reactions occur in cam plants