The present study was undertaken to survey the floristic composition in the islands and shorelines in Aswan Reservoir, south of the River Nile at Aswan Governorate, Egypt. Four elements of vegetation were analyzed: floristic composition, lifespan, life form, and phytogeographical affinities. A total of 165 species were recorded belonging to 134 genera in 45 families of vascular plants, of which six species were new to the flora of Aswan and Nubia (Amaranthus spinosus, Doellia bovei, Eleocharis parvula, Haematoxylum campechianum, Polygonum aviculare, and Pithecellobium dulce). The most represented families are Leguminosae, Poaceae, and Compositae. Species richness is highest in low-lying areas (shorelines) liable to flooding, compared to those of the islands in the river. The recorded flora consists of 50.91% perennials and 49.09% annuals. Therophytes and phanerophytes were the predominant life forms. Phytogeographical analysis revealed the prevalence of the pantropical (28.48%), palaeotropical (17.57%), and cosmopolitan (16.36%) plant species. Monoregional chorotype was represented by 29 species (17.58%) of the recorded flora with the Sudano-Zambezian species (11.52%) being the highest chorotype, while pure Mediterranean species were very poorly represented (3.63%). Biregional chorotype was represented by 25 species (15.15%), while the pluriregional chorotype was accounted for 2.43% of recorded species.

The present study analyses plant diversity and evaluates the relationship between edaphic variables and the distribution and grouping of plant species in the Aswan Reservoir area, South Egypt. The dominant families were Fabaceae, Poaceae, and Asteraceae, forming 38.82% of the total flora recorded. The main bulk of the flora recorded (50.59%) belonged to the cosmopolitan, neotropical, pantropical, and palaeotropical chorotypes. A TWINSPAN analysis produced 10 vegetation clusters. Inundation levels showed a high correlation with species richness. The seasonally inundated area in Bute El-Hasaya and Maezana Belal (cluster V) had the highest species richness (36.50), while the lowest species richness (4.50) was in the shoreline of Philae, Awad, and Heisa islands (cluster IX). The DCA ordination depicted the environmental gradient expressed by the cluster analysis, and the resulting vegetation groups represented a distinct microhabitat. The CCA ordination indicates that the separation of vegetation group (A) along the axis was affected by the concentration of K, Mg, and CO₃, and the vegetation group (B) was significantly associated with the total dissolved salts and the concentration of Cl. Moreover, the vegetation group (C) correlated significantly with pH, electrical conductivity, organic matter content, and SO₃, HCO₃, PO₄, Na, and Ca concentrations.

Amaranthus spinosus L. is a member of the Amaranthaceae family, commonly known as the spiny amaranth, or spiny pigweed. It is native to the tropical Americas, but is present on most continents as an introduced species, noxious weed, and can be a serious weed of rice cultivation in Asia. In Egypt, the Nile Delta, particularly Cairo, is the home of spiny amaranth; however, it has recently been recorded in the Nile Valley (Aswan area) colonizing different habitats such as roadsides, depressions, Khor and river banks. This study aimed to study the current distribution of spiny amaranth in the Aswan area and its associated species. It also aims at studying their life and growth forms, habitats, soil characteristics, local and global distributions, local threats, and spiny amaranth seed characteristics. Five sites along the river Nile in Aswan city was surveyed from the period of 2018 until 2025 in four identified habitats (Roadsides, depressions, khor, and river banks). Forty species were recorded associated with spiny amaranth, belonging to 38 genera and 16 families. Therophytes (15 species) followed by phanerophytes (14 species) were the most represented life form. All recorded species inhabit the Nile region, and most of the 12 taxa were pantropical. Most studied species (32.5% of the total threatened species) suffer from at least one type of threat. They mostly suffer from habitat loss due to industrial, urban, and tourist development. Soil samples were analyzed for edaphic variables. The relative importance of a certain environmental factor on the distribution of the recorded species across the four habitats were performed using PCORD (v6.22 software). The spiny amaranth seed colors are mainly dark brown to reddish brown, lenticular shape, glabrous and matte surface, acute apex, and obtuse to rounded base, hilum marginal, sub-basal, and slightly eccentric. Its length ranged from 7.24 to 7.84 mm, and its width varied between 7.27 and 7.77 mm. The authors recommended that monitoring the behavior of alien species and conducting ongoing surveys are crucial for biodiversity conservation.

The rate at which people are introducing species to formerly uninhabited places shows no signs of slowing down. Wild plants can roam freely across international borders. From September 2021 to June 2023, 45 field excursions were made to Egypt’s southern Nile Islands in the Aswan Governorate to undertake vegetation surveys. Depending on the literature reviewed and herbaria consulted during this study, three plant taxa, as well as one additional genus (Macroptilium), found during these field excursions were not previously recorded in the Egyptian Flora. These new records are Acanthospermum hispidum (Asteraceae), Geranium carolinianum (Geraniaceae), and Macroptilium atropurpureum (Fabaceae). These plants are classed as noxious weeds that harm agriculture. A complete description, occurrence and distribuion maps, plant photos and illustrations are provided. This study underlines the importance of carrying out extensive and ongoing research on the flora of Aswan’s Nile Islands to have a better knowledge of flowering plant distribution patterns. In addition, it might be regarded as a great starting point for expanding floristic knowledge of this interesting territory and its surroundings.

The current biodiversity crisis is motivating ecologists and conservation biologists to investigate the effects of human-induced changes to natural resources on species distribution and to comprehend ecological and evolutionary causes of spatial patterns of biodiversity. This work relies heavily on a variety of previously published works, and the large reference section includes all the literature citations required. The First Reach of the Nile River Region (FRNRR) extends from Old Aswan Dam to the new Esna barrages. It’s characterized by a huge number of islands and the maximum flow velocity from Aswan to the Mediterranean. There are few studies covering the flora and biodiversity in this region. This study tries to introduce complete information about this region and its characterized species. The database of the vascular flora of (FRNRR) was compiled, which includes 246 species belonging to 172 genera and 56 families. Pantropical, Palaetropical, and Cosmopolitan elements (54.47 % of the total flora) were the dominant floristic categories among the total number of species. The flora of (FRNRR) contributes about 31.8 % of the whole flora of the Nile region and 11.6% of all species in Egypt. This study is the most recent and exhaustive review to date that examines floristic diversity.