Borders between the 13 floristic regions are in most cases clearly evident, but for the following mainland regions certain specifications are given below:
- Border between StE and SPi – a line between the following points: 38.53/21.10 – 38.54/21.20 – 38.56/21.30 – 38.59/21.38 – 38.59/21.50 – 39.00/22.03 – 39.05/22.19.
- Border between SPi and NPi: a line between the following points: 39.37/20.11 – 39.38/20.30 – 39.39/20.41 – 39.40/20.58 – 39.46/21.06 – 39.44/21.14 – 39.44/21.21 – 39.43/21.26 – 9.44/21.30 – 39.47/21.45. The border between SPi and NPi in the Metsovo-Ioannina area has been drawn just S of the old national road so that the Katara Pass, the town of Metsovo and the meadows just N of Metsovo are all in NPi. It coincides (more or less) with the border between an area of limestone in the south and serpentine in the north.
- Border between NPi and NC: – in the Kastoria area follows an almost straight line from 40.21/21.18 to the Albanian border at 40.34/21.03, which places it c. 5 km SW of the town of Argos Orestikou.
- Border between StE – SPi – NPi and EC – NC: a line between the following points: 38.53/22.33 – 38.55/22.28 – 39.05/22.19 – 39.18/22.10 – 39.33/21.55 – 39.47/21.45 – 40.00/21.36 – 40.14/21.25 – 40.34/21.02.
- Border between EC and NC: a line between the following points: 39.33/21.55 – 39.42/22.13 and then along the Pinios River to the sea at 39.54/22.43.
- Border between NC and NE: along the Axios River from the Bulgarian border to the sea.
