There are many species of Crocus and even more cultivars. However Crocus vernus has been with us for a long time and has been naturalised for a long time. This is a print from Viridarium Reformatum, seu Regnum Vegetabile: Krauter Buch (Newly Revised Garden of the Plant Kingdom: Herb Book), Michael Bernhard Valentini (1657-1729) editor. Frankfurt, Anton Heinscheidt, 1719.
The photograph below may be C.vernus but I suspect it is another species called Crocus tommasinianus, the woodland crocus, or early crocus.
This photo was taken on 7th Feb 2018, in the churchyard of St. Michael, Tiddenham Chase, which is between Chepstow and Coleford in Gloucestershire. The church comprises a nave and chancel in Gothic style and was built on the Chase in 1888.
Crocus vernus is the blue or purple/blue flowered crocus as opposed to the yellow ones (Crocus chrysanthus) or ( Crocus flavus ), and the creamy white ones (Crocus chrysanthus).
To be honest the Crocus genus is a bit of a nightmare as there are over 30 different species and a vast number of different cultivars. To get an idea have a look at this wikipedia page on Crocus species.
The original cultivar is quite plain and rather thin. Over the years more bold forms have been developed, which have a stronger colour and a more substantial shape, also some have a less uniform colour, involving two tone stripes and white lines. Although one can see that even back in the 1700’s there were several different versions.
The photos below are of some crocuses we bought in the local garden center a couple of months ago, Inkpen in Berkshire was too far to go just for a crocus, ice though they are.
This is what the BSBI says about it
‘C. vernus, introduced into cultivation in Britain before 1600, is very common in parks and gardens and was first recorded in the wild in 1763. Some populations may be relics of cultivation as a substitute for saffron, and it is still found in great abundance at a few long-established sites such as at Inkpen (Berks.). It is unevenly recorded.’