Several types of landscape are represented, dependent upon the nature of the soil, each with its own characteristic vegetation, which makes it possible to differentiate them without difficulties.
The limestone bedrock is visible in the cliffs but on the plateau it is masked by superficial weathering. Near the slopes where the limestone is just under the surface, the vegetation is calcareous, with groves of pubescent oaks, juniper, dogwood and Montpellier maple. Several outcrops, from clays to gravel and tertiary pebbles, are dispersed primarily on the eastern edge of the plateau (the Templès). These outcrops are easy to spot because of the silicic vegetation (chestnut, ferns, heather) that they generate. |
Between the Puy d'Issolud farm and the spur limiting the plateau towards the south, the limestone substratum is masked by gravels resulting from gelifraction and clays created by weathering. This sector is cultivated (orchard, walnut and cereals).
At the base of the peripheral cliffs, the marls and Toarcian clays form an inclined slope supporting meadows. These clay soils are partially obscured by colluvium, travertines and scree from localised cliff collapse. These screes support some houses around the Loulié spring. In the east and north-east, a limestone bed (Upper Domérien) is inserted in the clay slope near the farms of Verdié, Belcastel, Maraval and Lastournayries. An accumulation of travertine masks the clay substratum downstream from the Loulié spring. |
The impact of human activities has been limited by the very steep slope. Timber felling regularly carried out in the past has not hindered the rapid regeneration of forest cover in the form of coppices or from natural seedlings.
The arboreal stratum dominated by downy Oak and hornbeam (Charmaie-Chenaie) is completed by:
Ivy (Hedera helix), wild madder (Rubia peregrina) and black bryony (Tamus communis), use the support of the trunks or branches to hoist themselves towards the light. The early flowering spurge laurel (Daphne laureola), the butcher's broom (Ruscus aculeatus) and the field rose (Rosa arvensis), whose branches spread out on the ground, form a modest shrub layer. The rich herbaceous layer provides evidence of good plant biodiversity conservation with a high number of geophytes, plants that in winter retain only organs buried in the earth (bulbs, tubers or rhizomes). Many can be maintained only in deep, undisturbed soils. From the first good days of winter and then throughout the spring their flowering is renewed, brightening the undergrowth with the freshness of their colours and the elegance of their inflorescence. Thus, in the month of January, the snowdrops (Galanthus nivalis) hatch, with their milky corollas; and the stinking hellebore (Helleborus foetidus) develops a generous bouquet of greenish-cream flowers above a rosette of evergreen fan-cut leaves. February-March brings a great parade of wild daffodils (Narcissus pseudonarcissus) whose wide-open bright yellow trumpet is surrounded by cream petals spread in a star. More discreet are the blooms of the violet (Viola alba), the early dog violet (Viola reichenbachiana) with purple blue corolla, and the alpine squill with two leaves (Scilla bifolia), a ravishing liliaceae with corollas of an intense blue. In March-April there is the lesser or common periwinkle (Vinca minor) which with its runners weaves real carpets on the ground, the narrow-leaved lungwort (Pulmonaria longifolia) stained with white, the greater stitchwort (Stellaria holostea), the cuckoo flower (Cardamine pratense), cruciferous with purple flowers, the European sanicle (Saniculum europaeum) with its short umbel of white flowers, the wood spurge (Euphorbia amygdaloides), the perennial dog's mercury, also of the spurge family (Mercurialis perennis), the lesser celandine or pilewort (Ficaria ranunculoides), etc ... In April-May it is the turn of Solomon's seal (Polygonatum multiflorum), a false lily of the valley whose narrow bells in short hanging clusters attach to the axils of the leaves carried on a long arched stem. The early purple orchid (Orchis mascula) with black-stained leaves, the common columbine or granny's nightcap (Aquilegia vulgaris) whose large skilfully crafted blue flower extends by five coiled spurs, germander speedwell or cat’s eyes (Veronica chamaedrys) and its small azure flowers in upright spikes, tuberous comfrey (Symphytum tuberosum), narrow-leaved bitter-cress (Cardamine impatiens), bush vetch (Vicia sepium), herb-Robert (Geranium robertianum), wood avens or St Benedicts herb (Geum urbanum), the parasitic ivy broomrape (Orobanche hederae), bird's nest orchid (Neottia nidus-avis), a rare saprophyte orchid whose flowers are pale brown on a long spike This plant derives its nutrition from a mycorrhizal fungus in the soil or litter which in turn derives nutrition from tree roots, the similar twayblade (Listera ovata/Neottia ovata), etc ... In May-June the beautiful golden heads of the leopard's bane (Doronicum pardalianches) open, and easily compete with the wall hawkweed (Hieracium murorum) and the wall lettuce (Mycelis muralis), the white umbels of the cow parsley (Anthriscus sylvestris), the long clusters of delicate pale green flowers of the wild asparagus (Ornithogalum pyrenaicum), the garden star of Bethlehem or grass lily (Ornithogalum umbellatum) and its white star-shaped flowers, the discreet three-veined apetalous sandwort (Moehringia trinervia), the greenish-leaved greater butterfly orchid (Platanthera chlorantha), the beautiful ppeach-leaved bellflower (Campanula persicifolia), the yellow cluster of hairy St. John's Wort (Hypericum hirsutum), the flat pea or narrow-leaved everlasting pea (Lathyrus sylvestris) which evokes the sweet pea, and especially the rare martagon lily or Turk's cap lily (Lilium martagon) - highly toxic to cats - with scented pink flowers and petals punctuated with purple, whose small population must be scrupulously respected. Some grasses, sedges and junceae characteristic of fresh undergrowth accompany the species already mentioned: Melique uniflora (Melica uniflora), Millet spread (Millium effusum), Bromegrass (Bromus asper), Carex forest (Carex sylvatica), Luzule de Forster (Luzula Forsteri), etc ... |
Spaces favorable to xerothermophilic undergrowth are provided in these areas of fairly sparse forest cover, on shallow soil or on relatively stabilised scree, sometimes anchored directly on limestone outcrops in the form of ‘balms’ (cavities under an overhanging rock or ledge) or lapiaz, provides spaces.
The tree and shrub strata include, in addition to the downy oak, some species of Mediterranean or sub-Mediterranean affinities such as :
These plants like clearings and sunny edges on limestone, and are addtional to the Mediterranean species. Despite difficult living conditions (drought or low rainfall during the summer period with relentless sunshine and high temperatures, poor water retention capacity of lean and often very stony soils), the herbaceous layer is fairly rich in species that occur throughout spring and give a generous palette of colours:
They perfectly illustrate this xerothermophilic flora, along with :
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The discontinuous undergrowth - composed of characteristic grasses such as the blue moor grass (Sesleria caerulea), the erect brome (Bromus erectus), the Timothy Boehmer (Phleum boehmeri) - and the edge of the undergrowth, are favorable for the installation of some orchids :
On the gravelly and dusty soil of rock shelters where the oak groves cannot invade, some nitrophilic species are present (plants that prefer soil rich in nitrates, for example on land where certain wild mammals gather):
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alfalfa or lucerne,
barren brome, birds-eye speedwell, bulbous buttercup, cocksfoot, common fleabane, common sainfoin, crested dog’s-tail, |
field scabiosa,
garden bird's-foot trefoil, grape hyacinth, hairy common velvet grass, hare’s-foot clover, hedge bedstraw, marguerite, meadow salsify, |
meadow vetchling,
red clover, rough hawksbeard, ribwort plantain, marguerite, meadow foxtail, quaking grass, red rattle, |
ryegrass,
soft brome, tall oat-grass, white or Dutch clover, wild carrot, yellow rattle or cockscomb, etc... |
We will pass silently over the cosmopolitan flora of the areas now used for agriculture. Highly impoverished by the use of weedkillers, they give only a derisory image of the brilliant procession of species (cornflowers, poppies, corn-cockle, corn camomile, yellow loosestrife, delphinium, hemp-nettle , etc ..) which used to enliven the harvest with their vivid colour. |
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Monocotyledons (flowering plants the seeds of which typically contain only one embryonic leaf or cotyledon) :
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Dicotyledons (flowering plants the seeds of which typically contain two embryonic leaves or cotyledons) :
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The ruderal flora and weeds
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The flora of humid environments :
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On irrigated tufs :
Plants immerged or floating :
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