The Capparaceae (or Capparidaceae), commonly known as the caper family, are a family of plants in the order Brassicales. As currently circumscribed, the family contains 33 genera and about 700 species. The largest genera are Capparis (about 150 species), Maerua (about 100 species), Boscia (37 species) and Cadaba (30 species). Taxonomy The Capparaceae have long been considered closely related to and have often been included in the Brassicaceae, the mustard family (APG, 1998), in part because both groups produce glucosinolate (mustard oil) compounds. Subsequent molecular studies support Capparaceae sensu stricto as paraphyletic with respect to the Brassicaceae. However Cleome and several related genera are more closely related to members of the Brassicaceae than to the other Capparaceae. These genera are now either placed in the Brassicaceae (as subfamily Clemoideae) or segregated into the Cleomaceae. Several more genera of the traditional Capparaceae are more closely related to other members of the Brassicales, and the relationships of several more remain unresolved. Based on morphological grounds and supported by molecular studies, the American species traditionally identified as Capparis have been transferred to resurrected generic names. Several new genera have also been recently described. Based on recent DNA-analysis, the Capparaceae are part of the core Brassicales, and based on limited testing, the following tree represent current insights in its relationship. Genera Excluded genera Borthwickia W.W.Sm. → Resedaceae Cleome L. → Cleomaceae Cleomella DC. → Cleomaceae Dactylaena Schrad. ex Schult.f. → Cleomaceae Forchhammeria Liebm. → Stixaceae Haptocarpum Ule → Cleomaceae Koeberlinia Zucc. → Koeberliniaceae Oxystylis Torr. & Frem. → Cleomaceae Pentadiplandra Baill. → Pentadiplandraceae Podandrogyne Ducke → Cleomaceae Polanisia Raf. → Cleomaceae Setchellanthus Brandegee → Setchellanthaceae Stixis Lour. → Stixaceae Tirania Pierre → Stixaceae Wislizenia Engelm. → Cleomaceae Additional genera to be excluded from the Capparaceae, according to Kers in Kubitzki 1. Genera that may be capparalean but do not fit within the Capparaceae Neothorelia Gagnep. 2. Genera insufficiently known, but whose descriptions indicate they cannot belong to the Capparaceae Borthwickia W.W.Sm. → Borthwickiaceae Keithia Spreng. Poilanedora Gagnep. 3. Genera not treated in Kubitzki, but usually regarded as Capparaceae Buhsia Bunge Niebuhria DC. References Further reading Cornejo, X. & H. H. Iltis. 2006. New combinations in Capparaceae sensu stricto for Flora of Ecuador. Harvard Pap. Bot. 11(1): 17–18. Cornejo, X. & H. H. Iltis. 2008a. Two new genera of Capparaceae: Sarcotoxicum and Mesocapparis stat. nov., and the reinstatement of Neocalyptrocalyx. Harvard Pap. Bot. 13(1): 103-116.