The diversity of native non-crop (“weed”) vegetation in agricultural landscapes can provide arthropod natural enemies with food sources and shelter, thus improving natural pest control and reducing dependence on chemical pesticides. Moreover, native plants to a region are uniquely positioned to provide cultural ecosystem services such as wild food and wild medicinal plants, as well as aesthetics values. The Mediterranean Basin is one of the world’s richest places in terms of plant diversity. Olive cultivation is the basic tree cultivation in the Mediterranean and dominates its rural landscape. The olive grove ecosystem, whose flora presents a notable resemblance to the flora of Mediterranean type ecosystems, is home to a myriad of species of insects, spiders and other arthropods. This includes over one hundred phytophagous species, plus an uncounted number of entomophagous that help to reduce phytophagous populations. Here we present data on flowering plant species from the ground cover of olive groves, store information on characteristics of plant species namely physiognomic type and flowering period, geographic information and some statistical values on olive groves study area and records in the flora of visitor arthropods and cultural ecosystem services. The data include information on 36 olive groves, 100 flora species (taxa), of which 86 native in Portugal, 5 endemic to Iberian Peninsula and 4 endemic to Portugal Continental, and present also a summary of the records of visitor arthropods in these flora (i.e. 2 classes, 6 orders and 12 families).