If a tree sprouts out of the roots of another tree it is Chayav in Orlah. (1)
If the tree sprouts from the bark of the other tree according to R. Meir it is Chayav on Orlah and according to R. Yehudah it is Patur from Orlah. (2)
If there are two adjoining gardens and one is on higher ground than the other and a vegetable is growing on the incline between the two gardens R. Shimon says that if the vegetable was within arms reach of the upper garden it belongs to him and if not it belongs to the lower garden.
D'Vei R. Yanai says the vegetable only belongs to the upper garden according to R. Shimon if he doesn't have to extend himself to reach it.
It is a Safek according to R. Shimon if the vegetable belongs to the upper garden if he could reach only the roots or only the only the upper part but not the roots if the vegetable belongs to the upper garden.
A BIT MORE
1. Although the tree it is growing from is more than three years old and is Patur from Orlah however the new tree that grows from its roots is regarded as a separate tree and is Chayav in Orlah
2. R. Meir holds that the new tree that grows from its bark is regarded as a separate tree and is Chayav in Orlah, while R. Yehudah holds that it is it is considered a branch of the tree that it is growing from and it is Patur from Orlah.
The Gemara states that they said over in front of King Shevor the Din of R. Shimon and he praised it. Rashi says this is a reference to King Shevor who was the Persian King. The Maharitz Chiyus asks that it is forbidden to teach words of Torah to a non-Jew. The Maharitz Chiyus answers that it is permitted to teach him Torah with regards to the Sheva Mitzvos Bnei Noach and the Gemara states in Sanhedrin that the Dinim are one f the seven Mitzvos and the Din of R. Shimon is included in Dinim.
If there are two adjoining gardens and one of them is on higher ground than the other and a vegetable is growing on the incline if the vegetable can be reached from the upper garden and pulled out from its roots without extending himself it belongs to him and if not it belongs to the lower garden. Even if the entire incline can be reached from the upper garden anything that is growing within three Tefachim of the lower garden belongs to the lower garden. If the upper garden can reach the vegetable but can't reach the roots he may not take it but if he takes the vegetable it is not be taken from him. (Shulchan Aruch CM 167:1)