Brassicales

Brassicales is an order of flowering plants within the rosids, a major clade of angiosperms. In modern classifications, it comprises a diverse group of families united by shared chemical and morphological features, though the exact composition can vary among treatments. The best known family is Brassicaceae, the mustard or cabbage family, which includes many vegetables such as cabbage, broccoli, and canola, as well as the model plant Arabidopsis thaliana.

Other commonly recognized families in Brassicales include Caricaceae (papaya), Tropaeolaceae (nasturtiums), Resedaceae (mignonette), and Moringaceae (the drumstick tree). Some classifications also treat Capparaceae (capers) and Cleomaceae (spiderflowers) as separate families within Brassicales, while others place them in a closely related grouping or merge them with Capparaceae.

Distribution and ecology: Brassicales species are found worldwide, with high diversity in temperate regions as well as tropical and subtropical floras. Members range from herbs to shrubs and small trees, occupying a variety of habitats.

Characteristics: A common chemical feature of many Brassicales is the presence of glucosinolates, sulfur-containing compounds that yield pungent isothiocyanates when plant tissue is damaged. Floral and fruit morphology varies by family; in Brassicaceae, four-petaled flowers and fruits that are siliques or silicles are common, though this is not universal across the order.

Evolution and significance: Molecular data support Brassicales as a coherent clade within the rosids, with a fossil record dating back to the Cretaceous. Economically and ecologically important members include major food crops, condiments, and ornamental plants.