It looks to me like a Chinotto, or myrtle-leaf orange, Citrus myrtifolia, which is closely allied to the sour oranges. In any case, lemon pollen would have no effect at all on fruit flavor.

I'd vote for maybe Meyer lemon? they are more round than other lemons, color up a little more orange color that most lemons but are definitely lemon flavor, just a little less acid that most lemons but still tart, and the dark bark for an in ground tree is about right. the exact parentage of Meyer is not known, as it was discovered in the open, rather than part of a breeding program, but some have speculated that it may have been a cross with a lemon and an orange.

But softmentor, the photo doesn't look even vaguely like a 'Meyer'???