Amaranthaceae
Amaranthaceae Juss. comprises approximately 180 genera and more than 2,500 species distributed worldwide. Molecular phylogenetic studies have resulted in a broadened circumscription of Amaranthaceae, incorporating the formerly recognized family Chenopodiaceae, which is now treated as the subfamily Chenopodioideae within Amaranthaceae. This expanded concept is now widely accepted in modern plant taxonomy.
Key characteristics
- Amaranthaceae comprises annual or perennial herbs, shrubs, subshrubs, climbers
- Leaves are simple, alternate or opposite, exstipulate, and usually entire
- Inflorescences are typically spikes, panicles, heads, or clusters composed of numerous small
- Flowers are generally bisexual or unisexual, actinomorphic, and possess a persistent
- Stamens usually equal the number of tepals and are frequently united at the base into a membranous
- The ovary is superior, unilocular, with a single basal ovule
Distribution
Amaranthaceae is cosmopolitan, occurring on every continent except Antarctica. The family is particularly diverse in tropical, subtropical, and warm temperate regions, with numerous species adapted to arid, semi-arid, saline, and disturbed habitats. Members are common in deserts, grasslands, coastal marshes, agricultural fields, wetlands, and mountain valleys. The former chenopod lineage is especially abundant in dry and saline ecosystems of Central Asia, the Mediterranean region, Australia, and western North America. In Pakistan, Amaranthaceae is one of the most widespread plant families and is represented by numerous genera, including Amaranthus, Atriplex, Bassia, Beta, Chenopodium, Haloxylon, Salsola, Suaeda, and Halogeton. Species occupying cultivated fields, roadsides, deserts, salt flats, coastal marshes, riverbanks, alpine valleys, and wastelands. The family is particularly well represented in the saline plains of the arid regions of the Thal, Cholistan, and Thar deserts.