Quercus robur | Quercus ilex | Quercus petraea | Quercus alba | Quercus cerris | Quercus virginiana | Quercus rubra | Quercus garryana | Quercus acutissima | Quercus palustris | Quercus minima | Quercus fusiformis | Quercus castaneifolia | Quercus agrifolia | sand live oak (''Quercus geminata'') | Quercus × warei | ''Quercus'' × ''warei'' | Quercus suber | ''Quercus robur'' | Quercus peninsularis | Quercus lusitanica | Quercus lobata | Quercus laceyi | Quercus ilicifolia | Quercus hemisphaerica | Quercus havardii | Quercus glauca | Quercus frainetto | Quercus engelmannii | Quercus copeyensis |
All told, the arboretum contains more than 800 varieties of trees and shrubs, with extensive collections of Chamaecyparis, Juniperus, Taxus, and Thuja, as well as roses and fine specimens of Acer griseum, Cornus controversa, Cupressus sempervirens, Juniperus deppeana, Pseudotsuga menziesii, and Quercus pyrenaica.
Forests and smaller wooded areas within the park are comprised mainly by cork oaks (Quercus suber), Portuguese oaks (Quercus faginea), Pyrenean oaks (Quercus pyrenaica), olive trees (Olea europaea), alders (Alnus glutinosa and Alnus incana incana), holly trees (Ilex aquifolium), bay laurels (Laurus nobilis), rhododendrons (Rhododendron ponticum), ferns, mosses, and lichens.