Chabouillet, Anatole. Catalogue général et raisonné des camées et pierres gravées de la Bibliothèque impériale. Paris : 1858, n°1531.
I think it likely by the by that this gem was originally in the Medici collection based on Gori’s illustrations.
Most of the trees on the intaglios are leafy and bear no visual relationship to RRC 235/1.
Notice also that the tree has a bird in it. The catalogue says a woodpecker but this is a stretch of an assertion. I’ve been obsessed by the bird question before.
This is by far the closest visual parallel I’ve found. And interestingly it provides a parallel also for the head on this Sard in the Etruscan style for the BM (1814,0704.1319).
I’ve discussed this gem before on this blog.
wolf and twins
faustulus
gems
Liv Mariah Yarrow 
Is there a possible relationship to the female head and Cr. 127/1? http://numismatics.org/collection/1982.37.2 (Or is it a helmeted male or female head?) My copy of Crawford is not at hand so I haven’t looked up what he says about it, but in the past it has been attributed to the Hortatius gens…
Interesting idea! Crawford doesn’t speculate on identity of 127/1 head. I think on the gems its more likely to be either a personification of Roma or Mars with me leaning towards the former. On 127/1 I’d guess some sort of pun on the moneyer’s name or a goddess like Venus. The gems are good proof that floating heads in the field wouldn’t strike an ancient viewer as odd per se.