I think "orange" fits well for Poncirus. I have let the juice stand for one night in an open glas, then threw away the bottom fraction and made lemonade from the rest of the juice. It tasted primarily orange-like, not like a lemon (by the way better than both).
I ask myself though how it happend that the overall bad taste of Poncirus developed. What was its evolutionary advantage? What kind of animals love exactly that taste? I have picked up somewhere that the taste is designed for antelopes. Can that be true?
Well, animals sometimes have a very different taste from ourselves. Rabbits like bitter meadow. Many animals eat conifers. ... It could also be that some animals that are ruminants find fresh poncirus fruits just acceptable but love the taste of fermented fruits - I mean when they eat them a second time (ruminated). As I wrote above the bad flavour of Poncirus vaporizes over night totally (in case of better tasting fruits) or at least largely (in case of bad tasting fruits). The chemical changes in a rumina will be much greater.
Interesting speculation about antelopes Till. Fruit needs to pass through the body and survive, or partially eaten and some seed survive. . Transport of seeds by animals is called zoochory. I can't find specific information about citrus zoochory. Speculating on poncirus, especially with the large number of thorns, it doesn't want it's fruit to be eaten before the seed is ripe, thorns protect the fruit and the tree. When the fruit are ripe, they drop to the ground and are more readily available. The fruit resins which may keep the fruit from rotting degrade, and the fruit could become more palatable. Some animals that eat citrus are rats, monkeys, red panda, some bird species.