Cambridge milk parsley
The two plants are not only similar in appearance, but also grow in similar moist habitats, although they may be told apart in the following manner: P. palustre has hollow, often purplish stems, pinnatifid leaf lobes and deflexed bracteoles; while Selinum carvifolia has solid, greenish stems, entire or sometimes lobed leaf-lobes and erecto-patent bracteoles. Also, when the two plants are in fruit, another difference becomes apparent: the three dorsal ridges on the fruit of Selinum carvifolia are winged, while those on the fruit of P. palustre are not. Yet a further difference lies in the respective leaflets of the plants : those of Peucedanum palustre are blunt and pale at the tip, while those of Selinum carvifolia are sharply pointed and of a darker green.