This is the twelfth of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Asparagaceae (incl. Hyacinthaceae), Boraginaceae, Cactaceae, Caryophyllaceae, Chenopodiaceae, Compositae, Crassulaceae, Euphorbiaceae, Gramineae, Haloragaceae, Iridaceae, Labiatae, Leguminosae, Malvaceae, Orchidaceae, Orobanchaceae, Plumbaginaceae, Polygonaceae, Rosaceae, Scrophulariaceae (incl. Buddlejaceae), Solanaceae and Umbelliferae. It includes new country and area records and taxonomic and distributional considerations for taxa in Abutilon, Aegilops, Amelanchier, Andryala, Aruncus, Asparagus, Bellevalia, Brugmansia, Buglossoides, Bupleurum, Cortaderia, Crassula, Datura, Dysphania, Euphorbia, Fallopia, Iris, Lycianthes, Myriophyllum, Nicodemia, Onobrychis, Ophrys, Opuntia, Orobanche, Phelipanche, Plumbago, Salvia, Silene, Stellaria and Wisteria, and new combinations in Amelanchier and Phelipanche.