The Allen and Greenough is still under construction;
so some links may not work quite the way you would expect.
189. Many verbs have more than one set of forms, of
which only one is generally found in classic use: -
lavó, laváre or
lavere, wash (see § 211. e).
scateó, scatére or
scatere, gush forth.
-áre, or lúdificor,
fulgó, fulgere, or fulgeó, fulgére, shine.