The pinewood is characterized by the presence of pine trees and pines, with the first ones that are no longer present in the proximity of the coast and the second towards the hinterland. The large sotobosco consists of shrub species of the Mediterranean with Phillyrea (lillatro), mastic (sontrio), Myrtle (Myrtle), rare Oaks and some Cork oaks (the latter in the stretch between Castiglione della Pescaia and Marina di Grosseto).
The original pinewood, significantly less than the current extension was characterized almost exclusively by pine trees and Mediterranean vegetation, and was interested in the areas closer to the coast. During the 18th century, as a result of reclamation works carried out by the Lorraine, it was necessary to implant a high number of trees towards the hinterland, to avoid that the original swamp you reimpossessasse of the lands that had been torn with the canalization: it was decided, as well, the introduction of pines that are currently prevalent than maritime proportionally much endemic. The Pineta of Tombolo straddles the bike path Marina di Grosseto-Castiglione della Pescaia in the northern part and the bike path Marina di Grosseto-Principina a Mare in the southern one.