The plant life of Montsant is predominantly Mediterranean, with a certain degree of sub-
Mediterranean and Eurosiberian influence. The vegetation is divided between the areas where the deciduous oak and viburnum and the evergreen oak dominate (most of the space) and the dry oak forests of Portuguese oak which can be found in the more
humid valley floors and on the higher levels of the mountain range.
Woods of Portuguese oak are not common on Montsant, and those that do grow form small groves within the pine woods, making them mixed woods. In addition to the Portuguese oak (Quercus faginea) and the downy oak (Q. pubescens and Q. x cerrioides), there are Scots pine Pinus sylvestris) and Austrian pine (Pinus nigra ssp salzmanii). In these woods there are other deciduous trees such as the Danish maple (Acer opalus ssp. granatense), the Montpellier maple (Acer monspessulanum), and the hazel (Corylus avellana) which sprinkle the forest on the shady slopes and gullies, and which are especially visible in autumn, when the leaves take on different shades of yellow and red.
In addition to this, we will also find woods of Aleppo pine (Pinus halepensis) in the lower parts, growing above the undergrowth of rosemary and winter heather or Scots pine and Austrian pine on higher ground. The humid valley floors and riverbanks are able to sustain some non- mediterranean plant species such as fragments of downy oak groves, yew groves and incipient riparian forests. Poplar groves are the most common riparian woods and cover those areas where flooding is unlikely. They are made up of white poplar (Populus alba), Lombardy poplar (Populus nigra) and narrowleaf ash (Fraxinus angustifolia). Willow woods are riparian woods covering those areas that flood frequently. The willows (Salix alba, S. atrocinerea, S. elaeagnos, S. purpurea, S. fragilis) grow over the undergrowth of low shrubs and herbs, such as brambles, hops (Humulus lupulus) and apple mint Mentha suaveolens). Reed beds are formed by species that flourish in flooded, shallow rivers, such as the common reed (Phragmites australis), the narrowleaf cattail (Typha angustifolia) and the bulrush (Scirpus maritimus). In the more sheltered areas of Montsant, frequently found plants are box (Buxus sempervirens), Phoenician juniper (Juniperus phoenicea), prickly juniper (Juniperus oxycedrus) and bearberry Arctostaphyllos uva-ursi var crassifolius).
The large area covered by rocky ground makes the Park unique, rich in the elements common to this type of environment, such as the communities of rock willow. The cliff and rock faces are home to a whole range of plant species that cling directly to the rock, making the most of what little soil accumulates in the cracks and holes in calcareous rock, such as the globe flower (Globularia repens), the potentilla (Pontentilla caulescens) and the rock tea (Jasonia saxatilis). In addition, the foot of the mountain, especially where the oak woods dominate, shows the influence of continental species, such as the barberry (Berberidetum aragonense)