List of nitrogen-fixing-clade families
The nitrogen-fixing clade consists of four orders of flowering plants: Cucurbitales, Fabales, Fagales and Rosales. This subgroup, the COM clade and the order Zygophyllales constitute the fabids under the fourth Angiosperm Phylogeny Group (APG IV) system. The nitrogen-fixing clade encompasses 28 families of trees, shrubs, vines and herbaceous perennials and annuals. The roots of many of the species host bacteria that fix nitrogen into compounds the plants can use. The trees of this subgroup dominate many temperate forests. Cannabis, with the psychoactive drug tetrahydrocannabinol (THC), has been used recreationally and ceremonially for at least 2400 years, but was in cultivation at least 6000 years before that for its oils and for making fabric and rope. Cucumbers, melons and watermelons are cultivated around the globe. The Mediterranean diet around 6000 years ago included fava beans, lentils, chickpeas and other legumes. Chestnuts were spread throughout Europe by the ancient Romans. The apple (in the rose family) is the second-most-cultivated sweet fruit, after the grape (in the order Vitales, not in this clade). Glossary
From the glossary of botanical terms:
annual: a plant species that completes its life cycle within a single year or growing season
basal: attached close to the base (of a plant or an evolutionary tree diagram)
climber: a vine that leans on, twines around or clings to other plants for vertical support
deciduous: falling seasonally, as with bark, leaves or petals
herbaceous: not woody; usually green and soft in texture
perennial: not an annual or biennial
succulent (adjective): juicy or fleshy
unisexual: of one sex; bearing only male or only female reproductive organs
woody: hard and lignified; not herbaceous

Fabales is basal within this clade. Families

See also 
List of plant family names with etymologies

Notes

Citations

References

 
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Nitrogen-fixing-clade families
Nitrogen-fixing-clade families
nitrogen-fixing-clade families
Rosids