34a. Aerial leaves distinctly compound, with 3-11 leaflets =Water Cress, Radicula nasturtium-aquaticum.= 34b. Aerial leaves merely serrate to pinnatifid; the submerged leaves, if present, dissected =Lake Cress, Radicula aquatica.= 35a. Flowers 5 mm. broad, or less --36. 35b. Flowers 6 mm. broad, or more --39. 36a. Stem-leaves irregularly pinnatifid or lobed; pod about as broad as long (2-4 dm. high; flowers in summer) =Garden Cress, Lepidium sativum.= 36b. Stem-leaves distinctly pinnatifid, with 3-6 pairs of lateral segments (spring) (Bitter Cress) --37. 37a. Leaves chiefly basal, pubescent on the upper side (1-3 dm. tall) =Bitter Cress, Cardamine hirsuta.= 37b. Stem-leaves conspicuous, glabrous on the upper side --38. 38a. Plant of dry soil; flowers about 3 mm. wide (1-4 dm. high) =Bitter Cress, Cardamine parviflora.= 38b. Plant of moist or wet soil; flowers about 5 mm. wide (2-8 dm. high) =Bitter Cress, Cardamine pennsylvanica.= 39a. Leaves irregularly pinnatifid or lobed, not segmented into definitely paired divisions (coarse plants 4-8 dm. high; flowers in summer) --40. 39b. Leaves deeply segmented into 3-10 pairs of divisions --41. 40a. Flowers pink or white from the first =Radish, Raphanus sativus.= 40b. Flowers yellow at first, turning white with age =Wild Radish, Raphanus raphanistrum.= 41a. Flowers pink or white, appearing in spring (2-5 dm. high) =Cuckoo Flower, Cardamine pratensis.= 41b. Flowers yellowish or cream-color; a weed blooming in summer (5-10 dm. high) =Sisymbrium, Sisymbrium altissimum.= 42a. A fleshy, much-branched plant of the shores of the Great Lakes, with a pod transversely divided into two joints (2-3 dm. high; summer) =Sea Rocket, Cakile edentula.= 42b. Pod not transversely divided into two joints --43. 43a. Pod short, its length not more than 3 times its diameter --44. 43b. Pod long and slender, its length more than 3 times its diameter --55. 44a. Pods not conspicuously flattened, thick and plump, about circular in cross-section (flowers in summer) --45. 44b. Pods distinctly flat --46. 45a. A plant escaped from cultivation in dry or moist soil, with very large basal leaves (5-10 dm. high) =Horse Radish, Radicula armoracia.= 45b. A plant of water or very wet soil, the largest leaves seldom more than 15 cm. long (1-5 dm. tall) =Lake Cress, Radicula aquatica.= 46a. Stem-leaves clasping the stem by an auricled base --47.