Within an alluvial forest massif, there may be a wealth of flora and certain plant species are considered typical of Rhine forest flora. The black polar, willow, oak and other wild apple trees (Malus sylvestris) covered in climbing plants are part and parcel of the Rhine jungle.

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Trees

The alluvial forests contain a great diversity of trees and shrubs, some of which are quite remarkable, like the Black Poplar (Populus nigra). This is a tree typical of alluvial habitats that may reach heights of 30 to 35 metres and live for 200 years (400 years for the oldest subjects). But the various hybrid poplars introduced for poplar cultivation or ornamental purposes may pollinate the wild black poplars and "pollute" their genetic heritage. Furthermore, human interventions in the alluvial habitat (rectification, ponding, damming) have contributed to the fragilisation of the species.

Other tree species have adapted to this alluvial situation, such as the Ash (Fraxinus excelsior), the White Willow (Salix alba), the Oak (Quercus robur) and the Sycamore Maple (Acer pseudoplatanus). Other species are less commonplace, like the White Elm (Ulmus laevis), the Cornelian Cherry (Cornus mas) and the Wild Apple (Malus sylvestris).

 

Climbing plants

Some of these species, like Common Ivy (Hedera helix), get a bad press but are an integral part of Rhine forest flora and are even one of its typical characters. These are Common Ivy, Common Hop (Humulus lupulus), Old Man's Beard (Clematis vitalba) and the rare and protected Wild Grapevine – the ancestor of our cultivated vine (Vitis vinifera subsp. sylvestris), which make the forest look like a jungle.

The Wild Vine, also called the Lambrusca Vine, is thought to be the ancestor of our own grape vine, but it is threatened owing to the fragmentation and regression of alluvial habitats and its susceptibility to diseases caused by the cultivated vine. Its sensitivity makes it a protected species throughout France.

We should bear in mind that climbers are epiphytic plants (they only use the tree as a tutor to get to the light) and not parasitic plants. They do not damage the tree on which they grow in any way.

Undergrowth

No less can be said of the undergrowth but it is in spring that it is at its most spectacular. In April, wild garlic (Allium ursinum), an aromatic plant from the very widespread Alliaceae family, covers the undergrowth with a carpet of green and white. Among the tufts of Wild Garlic, we also find Two-leaf Squill (Scilla bifolia), Common Toothwort (Lathraea squamaria) and, in the drier areas, Lily of the Valley (Convallaria majalis). Toothwort has a particular feature: it is a parasitic plant that draws its nutrients from the roots of its hosts (trees such as the alder and the hazelnut) using haustoria.


Photographs:
Old Man's Beard - Common Hop - Wild garlic