1.  flower definitely whorled or mostly so

    2. keel ciliate on upper margins near the claws

        3. keel ciliate on lower edges also, near the claws
           plants 0.5-1.5 dm tall; peduncles 2-4 cm long    l. concinnus var. brevior

        3'. keel not ciliate on lower edges

             4.  banner 8-9 mm long, 2-6 mm wide; flowers suberect at anthesis ...   l. ruber = l. microcarpus var. microcarpus
             4'. banner 12-16 mm long, 8-9 mm wide; flowers spreading at anthesis ...  l. densiflorus = l. microcarpus var. densiflorus


   2'.  keel ciliate on upper margins toward the apex or not ciliate at all  .... L. bicolor


1'.  flowers not at all whorled

     5. keel not ciliate

         6.  cotyledons petioled

              7.  leaflets linear-spatulate, mostly subglabrous above; plants sparsely spreading-pilose; flowers bluish-purple  ...  L. concinnus var. agardhianus
              7'. leaflets spatulate-oblanceolate to obovate, amply pubescent above; plants abundantly spreading-pilose; flowers pinkish-white to lavender

                    8.  lflets 1.5-3 mm wide    l. concinnus ssp. concinnus
                    8'. lflets 4-7 mm wide

                         9.  flowers 9-11 mm long   l. concinnus ssp. optatus
                         9'. flowers 6-8 mm long   l. concinnus ssp. orcuttii

         6'  cotyledons sessile ...  L. shockleyi

     5'.  keel ciliate at least on lower margin near the base

        10.  plant covered with long stinging hairs   l. hirsutissimus
        10'. plant lacking stinging hairs

               11. petals blue, lilac or purple

                     12. flowers blue to lilac, 7-17 mm long; leaflets mostly 1.5-3 mm wide

                             13.  flowers 10-13 mm long ...  L. sparsiflorus ssp. sparsiflorus
                             13'. flowers 7-11 mm long  ...  L. sparsiflorus ssp. pondii

                     12'. flowers pale purplish-pink, 8-10 mm long ...  L. arizonicus

               11'. petals pale blue to whitish or yellowish, 6-7 mm long ...  L. pallidus