A total of 243 vascular plant taxa were recorded across São Jorge Island, encompassing 89 families. These records correspond to 4,524 individual plant occurrences, including repeated observations of the same species across different sites. As each photographic observation is tied to unique geographic coordinates, all recorded specimens represent new spatial records for the Island's flora. Amongst the taxa, 53 are considered endemic to the Azores, 131 are introduced, 58 are native and one species (Dracaena draco (L.) L.) is of indeterminate status. These correspond to 1,773 individual occurrences of endemic taxa, 1779 introduced, 970 native and one with indeterminate status. At the family level, 31 families include endemic taxa, 63 include introduced taxa, 34 include native taxa and one family contains a taxon of indeterminate status.The inventory includes several noteworthy Azorean endemics, spanning both ferns and flowering plants. Amongst the ferns, notable records include Crisped Buckler Fern Dryopteris crispifolia Rasbach, Reichst. & Vida, Azorean Buckler Fern Dryopteris azorica (Christ) Alston and Azorean Rockcap Fern Polypodium macaronesicum subsp. azoricum (Vasc.) Rumsey, Carine & Robba. Iconic flowering species and woody endemics recorded during the survey comprise Azorean Cherry Prunus lusitanica subsp. azorica (Mouill.) Franco, Azorean Buckthorn Frangula azorica Grubov, Azorean Eyebright Euphrasia grandiflora Hochst. ex Seub., Azorean Greater-hawkbit Leontodon filii (Hochst. ex Seub.) Paiva & Ormonde and Narrow-lipped Butterfly Orchid Platanthera micrantha (Hochst. ex Seub.) Schltr. Additional endemic taxa include Azorean Dock Rumex azoricus Rech.f., Azorean Holly Ilex azorica Gand., Azorean Umbrella Milkwort Tolpis azorica (Nutt.) P. Silva and the hemiparasitic Azorean Dwarf Mistletoe Arceuthobium azoricum Wiens & Hawksw. Other significant native species recorded include the ferns Wilson's Filmy-fern Hymenophyllum wilsonii Hook., Killarney Fern Vandenboschia speciosa (Willd.) G.Kunkel and Scaly Tongue-fern Elaphoglossum hirtum (Sw.) C.Chr., Cretan Thyme Thymus caespititius Brot., Many-stalked Spike-rush Eleocharis multicaulis (Sm.) Desv. and the more common native Firetree Morella faya (Aiton) Wilbur.Amongst the most problematic surveyed exotic invasive plant species are the Ginger Lily Hedychium gardnerianum Sheppard ex Ker-Gawl., Knotweed Persicaria capitata (Buch.-Ham. ex D.Don) H.Gross, Bigleaf Hydrangea Hydrangea macrophylla (Thunb.) Ser., Crofton Weed Ageratina adenophora (Spreng.) R.M.King & H.Rob., Australian Cheesewood Pittosporum undulatum Vent. and the Wandering Jew Tradescantia fluminensis Vell., as well as the American Pokeweed Phytolacca americana L.
Petrone et al. (Thu,) studied this question.