The blood-vein, (Timandra comae) is a moth of the family Geometridae. It has a scattered distribution in Western and Central Europe north of the Alps. In the British Isles the distribution is patchy outside southern England and Wales. In far eastern Europe – east of a line running roughly from Finland through Estonia –, it is replaced by its sister species Timandra griseata. The species were split in 1931, only to be subsequently re-merged by most authors. But since 1994, new research has come out in favour of treating them as distinct species.