In the cereal fields plants as the corn marigold (Chrysanthemum segetum), the slender wild oat (Avena barbata) and plants of the species Vicia spp. commonly known as vetches. The wild radish (Raphanus raphanistrum spp.), which only appears at the first stages of the growth of the cereal, and the tassel hyacinth (Muscari comosum) are some of the other more abundant spontaneous plants.

In the fallow lands, the composite plants contribute the most to the sequence of spring colors. In the winter and even by the beginning of the spring, the dusky dogfennel (Chamaemelum fuscatum) is the responsible for the whiteness of the fields. Then comes the yellow of the field marigold (Calendula arvenses) and of the corn marigold (Chrysanthemum segetum) and some of the red of the poppies (Papaver spp.) and of the red dock (Rumex bucephalophorus). Lastly, we have the lilac mostly associated with the purple viper’s-bugloss (Echium plantagineum).

Other exuberant ruderal species are the Barbary nut (Gynandriris sisyrinchium), the Spanish false fleabane (Pulicaria paludosa), which is endemic to the South of Europe and the North of Africa, and the artichoke thistle (Silybum marianum) whose flower is used to curdle milk.

The sparse patches of montado have variable densities of holm oak (Quercus ilex spp. rotundifolia), some cork oak (Quercus suber) and sometimes a shrub layer mostly comprised of gum rockrose (Cistus ladanifer).

Gum rockrose is likewise the most abundant plant in the brushes, accompanied by other Cistacea as the Cistus crispus and the sage-leaved rockrose (Cistus salviifolius). In degraded soils we have more characteristically xerophyte plants as the broom (Genista hirsuta) and the Spanish lavender (Lavandula stoechas), an endemism of the Iberian Peninsula. At the level of the herbaceous stratum species as the purple false brome (Brachypodium distachyon), the subterranean clover (Trifolium subterraneum) and the white button (Anacyclus clavatus) stand out.

In the sunnier sites of some of the brushes (and fallow lands) it is also possible to find the Armeria neglecta, a Portuguese endemism restricted to the Campo Branco region which is classified as “Endangered” – high risk of extinction in the wild – and the Anacamptis boryi, an orchid classified as “Vulnerable” at a global scale.

In the herbaceous stratum of the cereal fields, the montados and the few, old olive groves, the Linaria ricardoi – a species endemic to the Portuguese mainland still restricted to the Baixo Alentejo – stands out.

Another rare endemic orchid of the Iberian Peninsula, the Biarum tenuifolium subsp. galianii, grows around the basis of olive tree trunks and road embankments.

The vegetation of the typically Southern European water courses is essentially formed by species with great ecological tolerance as the Oleander (Nerium oleander), the African Tamarisk (Tamarix africana) and the Securinega tinctoria, usually enwrapped by shrubs of elmleaf blackberry (Rubus ulmifolius). In the main water courses it is also possible to find some riparian curtains where the arboreal stratum is represented by trees as the Narrow-leafed Ash (Fraxinus angustifólia), the Poplar (Populus spp.) and the Willow (Salix spp.). Confined to the steeper slopes, the small patches of brushes contain shrub species as the Phillyrea angustifolia, the Wild Olive (Olea europaea sylvestris) and the Common Myrtle (Myrtus communis). The Lusitanian Water Clover (Marsilea batardae) and the Rush Daffodil (Narcissus jonquilla) – two species endemic to the Iberian Peninsula – stand out in the herbaceous stratum. In the margins and rocky beds of the water courses (where moist is preserved for longer periods of time), we have the Summer Lady’s-Tresses (Spiranthes aestivalis), an orchid present in Western half of Europe and in the North of Africa which is very rare in Portugal.

The small dams, weirs and ponds have wetland plants as the Broadleaf Cattail (Typha latifolia), the Lakeshore Bulrush (Schoenoplectus lacustris) and some Juncus (Juncus spp.). In regard to the existing flora in the Mediterranean temporary ponds (priority habitat 3170* of the EU Habitats Directive), the One-horned Eryngium (Eryngium corniculatum) stands out with a distribution limited to the Western region of the Mediterranean basin (Iberian Peninsula, Sardinia and Morocco).