Key to Thalictrum angustialatum and its morphologically similar species
1. Stamens 7‒10 mm long; styles circinate at apex; stigmas wingless .................................................................................. T. uncatum
1. Stamens 5‒7 mm long; styles straight; stigmas narrowly winged ....................................................................................................2
2. Carpels 10‒15; achene stipes ca. 1 mm long............................................................................................................. T. angustialatum
2. Carpels 1‒8; achene stipes 1.8‒2.5 mm long .....................................................................................................................................3
3. Stipels marginally torn; persistent styles slightly curved at apex......................................................................... T. sinomacrostigma
3. Stipels marginally entire; persistent styles ventrally reflexed at base........................................................................... T. leuconotum