7b. Leaves 3-5 times as long as broad, widest above the middle =Yellow Alyssum, Alyssum alyssoides.= 8a. Leaves lanceolate, gradually tapering to the base; flowers about 15 mm. wide =Sand Rocket, Diplotaxis muralis.= 8b. Leaves ovate, acute at base; flowers about 15 mm. wide --22a. 8c. Leaves entire or minutely toothed; flowers 5-10 mm. wide --9. 9a. Pods 25 mm. long or less, on slender pedicels about 8 mm. long =Worm-seed Mustard, Erysimum cheiranthoides.= 9b. Pods 20 mm. long or more, on stout pedicels about 4 mm. long =Worm-seed Mustard, Erysimum parviflorum.= 10a. Leaves bipinnate or dissected into very numerous divisions (3-8 dm. high; flowers in summer) --11. 10b. Leaves simply pinnate --13. 11a. Flowers about 5 mm. broad; pods about 20 mm. long by 1 mm. broad =Herb Sophia, Sisymbrium sophia.= 11b. Flowers about 3 mm. broad; pods about 8 mm. long by 2 mm. wide (Tansy Mustard) --12. 12a. Stems gray with a close fine pubescence =Tansy Mustard, Sisymbrium canescens.= 12b. Stems green =Tansy Mustard, Sisymbrium canescens var. brachycarpon.= 13a. Pod short, not more than 3 times as long as wide (coarse plants, preferring wet or sandy ground; flowers in summer) (Yellow Cress) --14. 13b. Pod elongated, more than 4 times as long as wide --17. 14a. Stems creeping, with erect or ascending branches; flowers about 8 mm. wide =Yellow Cress, Radicula sylvestris.= 14b. Stems erect or ascending (3-10 dm. high); flowers about 4 mm. wide --15. 15a. Pods about twice as long as the pedicels =Yellow Cress, Radicula obtusa.= 15b. Pods about as long as the pedicels, or shorter than them --16. 16a. Plant glabrous or minutely pubescent =Yellow Cress, Radicula palustris.= 16b. Plant hirsute =Yellow Cress, Radicula palustris var. hispida.= 17a. Petals 7 mm. long or more; pod terminating in a conspicuous beak (coarse, weedy plants, 3-12 dm. high, blooming in summer) --18. 17b. Petals of smaller size; pod not terminating in a conspicuous beak --24. 18a. Upper stem-leaves clasping at the base =Rutabaga, Brassica campestris.= 18b. Upper stem-leaves not clasping --19. 19a. Pod tipped with a slender cylindrical beak whose base is much narrower than the pod --20. 19b. Pod gradually narrowed at its tip into a stout, flattened or angled beak --22. 20a. Leaves oblanceolate, rather regularly pinnatifid, the terminal segment about the same size as the lateral ones =Sand Rocket, Diplotaxis muralis.=