Publication: Fl. N. Amer. 1: 584. 1840.
selected vouchers: WTU
Notes: H&C use the ending "a" throughout this genus, however this is incorrect due to the gender of the genus being plural neuter not singular feminine.
FNA8: "The presence or absence of bulbils is the only feature distinguishing Lithophragma glabrum and L. bulbiferum; for this reason L. bulbiferum is not recog-nized in this treatment. Bulbil production is extremely variable within the same clone in L. heterophyllum (R. L. Taylor 1965)."