Zygophyllaceae
Zygophyllaceae R.Br. family comprises approximately 27 genera and 285–300 species, distributed mainly in arid, semi-arid, and saline regions of the world. Molecular phylogenetic studies support the recognition of Krameriaceae as a separate family within Zygophyllales, while several genera formerly associated with Zygophyllaceae (e.g., Peganum) are now placed in Nitrariaceae. Members are characterized by opposite, usually compound leaves, often with swollen nodes, pentamerous flowers, a conspicuous nectariferous disc, superior ovary, and capsules, schizocarps, or drupaceous fruits.
Key characteristics
- Herbs, shrubs, or small trees
- Xerophytic or halophytic habit
- Leaves opposite, usually pinnately compound
- Leaflets fleshy or succulent
- Stipules present
- Flowers actinomorphic, pentamerous
- Nectariferous disc conspicuous
- Stamens usually 10
Distribution
The family occurs predominantly in North Africa, Middle East, Central Asia, South Asia, Mediterranean Basin, Southern Africa, Australia, Southwestern North America. Typical habitats include Hot deserts, Semi-deserts, Salt flats, Coastal saline plains, Dry grasslands, Rocky slopes, Sandy dunes. Zygophyllaceae is widely distributed in the arid and semi-arid regions of Pakistan. It occurs in Cholistan Desert, Thal Desert, Thar Desert, Salt Range, Kharan Desert. Habitats include Desert plains, Sandy dunes, Gravel deserts, Saline soils, Rocky hills, Dry riverbeds, Coastal salt marshes. Representative Pakistani genera include Fagonia, Tribulus, Zygophyllum, Tetraena, Balanites, Seetzenia.