Description: Mostly herbs or small shrubs, predominantly xerophytes and halophytes.
Leaves opposite or alternate, simple or pinnate, often fleshy; stipulate.
Inflorescence cymose or flowers solitary. Flowers actinomorphic, bisexual, 4- or 5-merous. Sepals 4 or 5, imbricate [rarely valvate], often persistent. Petals usually 4 or 5, imbricate or contorted, rarely valvate. Stamens usually twice the number of petals; filaments often with stipular or ligular membranous basal appendages; anthers 2-locular, dorsifixed, dehiscence latrorse. Disc usually present. Ovary superior, 3–5 [rarely 10–12]-locular, often vertically angled or winged; ovules axile, pendulous, 1 to several per loculus; style simple, angled or furrowed; stigma capitate or lobed.
Fruit a capsule, nut, or schizocarp; seeds with or without endosperm.
Distribution and occurrence: World: c. 22 genera, c. 200 species, mainly tropical & subtropical regions. Australia: 3 genera, c. 50 species, all States, chiefly arid & semi-arid districts.
Angiosperm Phylogeny Website (Family: Zygophyllaceae, Order: Zygophyllales)
The unnamed taxa given in Jacobs & Pickard (1981) are not listed as synonyms as they often include a number of species. Some species of Zygophyllum and Tribulus contain high levels of nitrate and may be poisonous to cattle and sheep. Nitraria and Peganum, hitherto often included in Zygophyllaceae, have been treated in families Nitrariaceae and Peganaceae respectively.
Text by Hj. Eichler & K. L. Wilson
| ||Key to the genera|| |
|1||Leaves more or less succulent, with 1 pair of leaflets or simple and 2- lobed at apex, glabrous, opposite; fruit without spines or tubercles, a 4- or 5-angled capsule or 3- or 4-winged; petals 4 or 5, yellow or white; stamens 4, 6, 8 or 10||Zygophyllum|
|Leaves not succulent, with 3–21 pairs of leaflets, usually hairy, opposite or the lower ones alternate; fruit with spines or tubercles, separating into 5 or (by abortion) fewer bony cocci; petals 5, yellow; stamens 10||Tribulus|