MYAGRUM Linnaeus, Sp. Pl. 2: 640. 1753.
Ihsan A. Al-Shehbaz
Name derivation: Greek muagron, the name of a species of mustard in Dioscorides and Pliny.
Lectotype species (designated by Britton & Brown, Ill. Fl. N.U.S., ed. 2, 2: 168. 1913; also by Green, Prop. Brit. Bot. 170. 1929): Myagrum perfoliatum Linnaeus.
Herbs, annual, glaucous. Trichomes absent. Multicellular glands absent. Stems erect, branched above. Basal leaves petiolate, not rosulate, simple, lobed to dentate, soon withered; cauline leaves sessile, auriculate to sagittate or amplexicaul, entire. Racemes many-flowered, ebracteate, corymbose, greatly elongated in fruit; rachis straight; fruiting pedicels hollow, sharply enlarged distally, appressed to rachis. Sepals oblong to ovate, free, caducous, erect to ascending, equal, base of lateral pair subsaccate. Petals yellow, erect, slightly longer than sepals; blade oblong to oblanceolate, obtuse at apex; claw undifferentiated from blade, glabrous, unappendaged, entire. Stamens 6, slightly exserted, tetradynamous; filaments wingless, unappendaged, glabrous, free; anthers ovate to oblong, obtuse at apex. Nectar glands distinct, lateral 4, median glands 2 and sometimes obscurely confluent with laterals. Ovules 2 per ovary, subapical. Fruits indehiscent silicles, obpyriform to clavate-obcordate, slightly angustiseptate, not inflated, unsegmented, broadest above middle, appressed to rachis; valves woody, glabrous, not keeled, smooth, wingless, unappendaged, distal 2 locules sterile, lower locule 1- or 2-seeded; replum rounded; style flattened, triangular; stigma capitate, entire, unappendaged. Seeds aseriate, wingless, oblong to obovoid, plump; seed coat not mucilaginous when wetted; cotyledons incumbent. x = 7.
Monospecific: S Europe and SW Asia, naturalized elsewhere.