These pictures are of some of the Australian native citrus varieties (formerly Microcitrus) in the Tintori "Hesperidarium" in Italy.
C. australasica, the finger lime. Fruit shape is very similar to the one growing in Naples Botanic Garden.
The cross-section is from
a fallen fruit, about  2cms in diameter.
A specimen of Microcitrus papuana, about 3' (1m) tall
A specimen of Citrus glauca, the Desert Lime, about 4' (1m30) tall.

page created 19th October 2004