how distinguish between kaffir lime and ichang papeda?

[Huyen Linh Ho]

 I have done some searching online and coukd not tell the difference in appearance bewteen kaffir lime and ichang papeda. I would appreciate if someone can show me a way to tell by looking at leaves or stem structure...

[SoCal2warm]

The leaves look very similar. However, the smell of the leaves are very different. Ichang papeda has only a faint lightly lemony smell.

I happen to be growing both Kaffir lime seedlings and Ichang papeda cuttings.
Maybe Ichang papeda has longer thorns?

[SoCal2warm]

Hmm, interesting, I just checked on my little Kaffir lime seedlings and they don't seem to have very big petioles. I harvested them from the fruits myself.

Maybe these are actually some different type of Kaffir lime, or maybe the winged petioles are not apparent until later?

I am looking at pictures online and it looks like maybe small Kaffir lime leaves do not develop a symmetrical sized leaf petiole until later.
https://petalsandwings.blog/2015/06/06/growing-kaffir-lime-from-seeds/
Their seedlings look a lot like mine.

A Vietnamese store near here is selling little plants of Kaffir lime, and they have the symmetric winged petioles. I've also bought fresh Kaffir lime leaves from them at the market.

[Huyen Linh Ho]

  Thank you for your interesting info about them. By instinct I agreeed that ichang papeda might have longer thorn though I never had an actual comparison. I went to a Vietnamese grocery store here and they also sold kaffir lime as well. Those kaffir lime they sold were ranging from 4' to 6', they did not appear to have very big thorns. Unfortunately, they did not carry any ichang papeda beside the kaffir lime to study.

  I guess it is nearly impossible to tell until they have fruits. The fruits of ichang papeda would have bumpy stripes in the vertical direction while kaffir lime have non-pattern bumps or wavy bumpy strips all over its fruits.

  I read several sources online about the history of ichang papeda, and some sources mentioned the use of ichang papeda fruits as lime substitute. Some other sources also claimed that ichang papeda in some rare occasion produced fruits that has the quality very close to lemon, isn't it true?

[lavender87]

  If you put kaffir lime and ichang papeda leaves under a light-bulb you would see significantly more bubble spots on the kaffir lime leaf than on ichang papeda leaf. I think those clear bubble spots on lime and lemon leaves are where they store citrus oil (the more bubble spots the more fragrance), and for that reason normal lemon or lime leaves would be more fragrant than a pocirus or papeda leaves.

  I used to wonder why the poncirus trifoliate leaves don't have much citrus fragrance. I then observed and compared them to other citrus leaves, I now could answer my own question about it.

[Millet]

Lavender87, excellent post.  I never thought about that as a method of leaf identification.