| PACMAD clade | |
|---|---|
 | |
| switchgrass (Panicum virgatum) | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Clade: | Commelinids |
| Order: | Poales |
| Family: | Poaceae |
| Clade: | PACMAD clade |
| Subfamilies | |
ThePACMAD clade (previously PACCMAD, PACCAD, or PACC[2]) is one of two majorlineages (orclades) of the true grasses (Poaceae), regrouping six subfamilies and about 5700 species, more than half of all true grasses. Itssister group is theBOP clade. The PACMAD lineage is the only group within the grasses in which theC4 photosynthesis pathway has evolved; studies have shown that this happened independently multiple times.[3]
The name of the clade comes from the first initials of the included subfamiliesPanicoideae,Arundinoideae,Chloridoideae,Micrairoideae,Aristidoideae, andDanthonioideae. It has no defined taxonomic rank but is used frequently because it refers to a well-definedmonophyletic group with a distinct ecology.
Phylogeny of the PACMAD clade, withphotosynthetic pathways for each subfamily:[3]
| Poaceae |
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Grasses (Poaceae or Gramineae) | |||
|---|---|---|---|
| Morphology |  | ||
| Ecology | |||
| Subfamilies | |||
| Uses | |||