Hottonia palustris

The "Bosco di Tanali" Natural Reserve, especially after its recent extension, presents a mosaic of wetland plant biotopes.

The most important plant association is the hygrophilous Black Alder Wood, one of the last flood forests of the ancient Bientina Marsh.

On these once inundated lands, the European Alder  (Alnus glutinosa) joined the White Poplar (Populus alba), the English Oak (Quercus robur), the European Elder (Sambucus nigra) and the Willow (Salix cinerea); this last species forming thick shrubland in the outer woods.

The underwood shelters rare plants such as the small Marsh Bedstraw Galium palustre, the white flowers of Milk Parsley Peucedanum palustre, the white flowers of Milk Parsley (Osmunda regalis).

Where the water persists longer, the wood gives way to tall marsh grasses, which form the following associations:

  • Magno Sedge Beds - composed of large clumps of tufted sedge (Carex elata) with its roots submerged in the water and which offers shelter to rare plants such as the Summer Snowflake (Leucojum aestivum) and the Stachys palustris;

  • Marsh cane field - very thick and vital, dominated by Marsh Reed (Phragmites australis) and clambering plants like Bittersweet (Solanum dulcamara), Hop (Humulus lupulus) and Hedge Bindweed (Calystegia sepium).

In the water which collects in the pools and canals crossing the oases, grow what are now rare hydrophytes such as the Water Violet (Hottonia palustris), Southern Bladderwort (Utricularia australis) and Frogbit (Hydrocharis morsus-ranae). When the pools dry, they form wet meadows.

Here grow rare species such as Hampshire Purslane Ludwigia palustris, included in the red list for Italian plants, and various species of rush, Jointed Rush (Juncus articulatus), Bulbous Rush (J. bulbosus) and Toad Rush (J. bufonius).

Finally, the occurrence of the Arrow-Head (Sagittaria sagittifolia), an extremely rare plant on the national level which grows on the banks of the canals, deserves special mention.

Over the last few years, certain species have fallen dramatically in number as a result of the proliferation of the Red Swamp Crayfish.