A medium-sized Pyrgus that I encounter most frequently at medium to high altitude, even though the altitude range given by Lafranchis is 0-2200m. It has a medium dark brown upperside ground colour and the female is said to have a brassy olive tinge, although I have rarely seen this (maybe 33377?), but probably because I have not seen many fresh females.

The upf is - usually but not always - very lightly marked with smallish white spots in both sexes, usually more strongly marked in the male. The uph is - usually - almost completely unmarked except for very pale, almost vestigial, markings.

However, I have seen examples of what must be serratulae where the extent of the upf white marks is considerably greater than the classic pattern, and there are some examples on this page. It is also true that some serratulae have uph marks that are much more contrasted than the norm, although in my experience, this is infrequent. 36192 is an example.

It is a widespread altitude Pyrgus, found in greater or lesser numbers, sometimes in very large numbers indeed. It is also, in my experience, a hugely variable species, both in terms of the ups ground colour and in the size and strength of the upf markings.

The books, understandably, show typical serratulae with small upf markings, e.g. 45505. Whilst this may be typical, it is not definitive, and it often leads people to assume that if it does not look like the book illustration, it cannot be serratulae. The books, equally understandably, are reluctant to mention the degree and range of variability.

The unh ground colour is olive to yellow-green, this being the reason for its English name.

The unh distinguishing features are the rather solid-filled rounded arc-shaped marks in marginal s2; the discal s1 rounded but non-leaning bump; and, most often quoted, the basal spot in s7 is circular or oval(-ish), although the limits of this feature are unclear as I suspect that there are serratulae where this mark is rather rectangular with heavily rounded corners and in this respect could give rise to confusion with other species.

the unh is thus also liable to variability albeit to a much more limited extent than the ups.

observations

a male, although the upf markings are rather stronger, equally the uph markings are virtually non-existent apart from a vestigial discal mark.

a typically-marked male, the degree of the upf white spots being the norm for this species, whereas several on this page show a heavy degree of markings that are not typical for this species.

A very unusual serratulae, with very dark, cold brown, areas on the uph with lighter, more contrasted regions, especially the discal mark. The upf is an odd mixture of dark patches on a rather sandy ground colouring (or vice versa). The dark patches are probably a clinal effect.

very pale and drab, with very few markings on the upf all of which are concentrated in s5-7, with s1-4 almost completely unmarked. The uph is almost completely unmarked with very pale, almost vestigial, markings. It is almost certainly a female based on body shape. It could be alveus, carlinae, or serratulae, the females of which are all lightly marked; I would plump for serratulae on the grounds that the uph is virtually unmarked (alveus and carlinae have pale but somewhat stronger uph markings), and the absence of any upf markings in s1-4 which matches the book illustrations of serratulae, whereas alveus and carlinae have some weak markings in these areas. The strength of the cell spot does give me some concerns about serratulae, though. All three have an upper altitude range in excess of 2000m, so the altitude would not tend to eliminate any of these three possibilities.