Despite the fact that damask rose (Rosa damascena Mill. var. trigintipetala Dieck) is an economically important aromatic plant, its growth and development has been severely suppressed by salt stress. Reports show that moringa leaf extract (MLE) or salicylic acid (SA) are involved in salt-stress tolerance. Nevertheless, scarce information is available about MLE or SA impacts on aromatic plants, especially damask rose under salinity. This investigation was, therefore, conducted to investigate the effects of MLE and (or) SA on salt-stress mitigation in damask rose. Rose plants were treated with 200 mmol·L⁻¹ sodium chloride, and foliar applied with MLE at 1:30 (v:v) and (or) 0.2 mmol·L⁻¹ SA. Foliar spraying with MLE and (or) SA enhanced the growth attributes, chlorophyll content, relative water content, proline content, and membrane stability index under salinity. Less accumulation of malondialdehyde and H₂O₂ was also observed when MLE and (or) SA were applied. Furthermore, MLE and (or) SA applications considerably increased the radical scavenging activity, total phenols, and antioxidant enzyme activity (catalase and superoxide dismutase) under stress. The mitigative effect of MLE or SA was more pronounced when they were applied in combination. Collectively, MLE and (or) SA had efficient antioxidant defense system that scavenged reactive oxygen species, and thus afforded considerable protection against salt-induced oxidative damage.

Al-Wahbah Crater is the largest of five basaltic tuff rings and a unique habitat in Saudi Arabia that is considered the largest among its kind in the Middle East. The present study is the pioneer that describes the floristic composition and economic services provided by the recorded plant species in Al-Wahbah Crater northeast Taif Province, Saudi Arabia. The plant species were recorded through different sites along three main habitats (bed, terrace and slope). Thirty-two species (7 annuals and 25 perennials) belonging to 28 genera and 20 families were recorded in the different habitats of Al-Wahbah Crater. Fabaceae and Zygophyllaceae had the highest contribution, followed by Brassicaceae and Areaceae. The highest number of species was recorded on the slope of the crater, while the lowest was in the bed. Hyphaene thebaica was the dominant in the crater terrace, while Tetraena alba var. alba was the dominant in the crater bed, and the slope was dominated with Phoenix dactylifera, Cenchrus ciliaris and Fagonia indica. Chamaephytes were dominated over the other life forms. In addition, bioregional elements were dominated over monoregional and pluriregional taxa with the dominance of Sudano-Zmbezian elements. About 75.0% of the recorded species were medicinal, while 40.6% were either grazing or used as fuel and 18.8% were edible. Owing to the information resulted produced by the present study, which represents the base for further ecological studies, there is an urgent need for monitoring and conserving Al-Wahbah Crater and the corresponding microhabitats in Saudi Arabia.

Seed exomorphic characters of six species belonging to four genera of family Capparaceae were studied using light microscope (LM) and scanning electron microscopy (SEM) in order to determine the importance of seed features as taxonomic evidence. These species are Cadaba farinosa Forssk, Capparis decidua (Forssk). Edgew, Capparis cartilaginea Decne, Dipterygium glaucum Decne, Maerua crassifolia Forssk and Maerua oblongifolia (Forssk.) A. Rich. The diagnostic characters at level of the general and specific level are shape of seed, size, color, texture and seed coat surface. There is a wide range of variations of seed shape among the studied species. LM revealed that the studied seeds are mostly varying from ovate to globose or cardiac- shape. All of the seeds lack wings except Dipterygium glaucum Decne. and most of the seed is coarse texture. There are six main types of seed surface sculptures revealed by SEM investigation at higher magnifications; reticulate, rugose-striate, winding undulate, ribbed and papillate.