We present the first inventory of the segetal flora of Italian winter cereal crops and allied crop types. The database consists of over 30,000 records, derived from different sources. We provide information and analyses on life forms, chorotypes, Ellenberg indicator values and preferential habitats of the flora. The inventory includes 987 vascular taxa and nothotaxa (868 species, 118 subspecies and 1 nothosubspecies), belonging to 354 genera and 55 families. Characteristic segetal species are 128, while 740 are generalist or accidental species from other habitats. Species exclusive of segetal habitats are 47. One species is extinct, and one is not confirmed in Italy. We recorded 42 neophytes, 15 archaeophytes and 10 cryptogenic species. Segetal species that are threatened in Europe are 45. Species in the Italian Red List are four, and five are threatened endemic species. The most frequent species are Papaver rhoeas (1,045 records), Convolvulus arvensis (623) and Ranunculus arvensis (571). Most species are therophytes (64%) and have a Mediterranean (36%), wide (14%) or eastern (13%) distribution range. Mean Ellenberg indicator values revealed relevant ecological affinities between the inventoried flora and cultivated winter cereals. Our work represents the basis for future applied studies in botany, ecology and agronomy.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

Detecting patterns of species co-occurrence is among the main tasks of plant community ecology. Arable plant communities are important elements of agroecosystems, because they support plant and animal biodiversity and provide ecosystem services. These plant communities are shaped by both agricultural and environmental drivers. The pressure of intensive agriculture worldwide has caused the decline of many characteristic arable species and communities. Italy is the European country where arable plant biodiversity is the best preserved. In this study, we assessed the patterns of co-occurrence of rare and threatened arable plants in 106 plots of winter arable vegetation located from Piedmont to Calabria, in the mainland part of the country. For this purpose, we based our investigation on the analysis of a recently acquired dataset and on the European list of rare and threatened arable plants. We highlight how different species of conservation interest tend to occur in the same community. On the other hand, generalist and more competitive taxa show similar patterns of co-occurrence. We suggest that single species of conservation value could be suitable indicators of a well-preserved community. On the other hand, to be effective, conservation strategies should target the whole community, rather than single species.

The segetal flora of winter crops includes mostly native or archaeophyte annual species that are often strong specialists of their habitats. Threatened by the intensification of agriculture, segetal flora is particularly valuable from a perspective of biodiversity conservation and evolution. Moreover, it contributes to maintain biodiversity in agroecosystems and provides several ecosystem services. The dataset here described was set up to provide the first inventory of the segetal flora of Italian winter cereal crops and allied crop types, the latter including flax and autumn-sown legumes. It includes 24,676 georeferenced occurrence data deriving from 1,240 floristic and phytosociological relevés. The data were collected from the greater part of Italian territory, in a temporal range spanning from 1946 to 2018.

The weed vegetation of the bean “Fagiolo Cannellino di Atina” (Phaseolus vulgaris L.) and the red pepper “Peperone di Pontecorvo” (Capsicum annuum L.) PDO (Protected Designation of Origin) crops was surveyed by means of 16 relevés, sampled in four farms of southern Latium during July 2019. The relevés were subjected to multivariate analysis, which revealed that the two crops are weeded by vegetation types referable to two different subassociations of Panico-Polygonetum persicariae (Spergulo-Erodion, Eragrostietalia, Digitario-Eragrostietea). Namely, communities colonizing bean fields, which are more mesophilous and richer in Eurasian taxa, are ascribable to the subassociation sorghetosum halepensis. Communities colonizing red pepper fields, which are more thermophilous and richer in Mediterranean taxa, are ascribable to the subassociation cyperetosum rotundi. Floristic, structural, and chorological features of the communities are discussed in relation to environmental factors and agricultural management.