Three New Species of Convolvulus L. Records to The Flora of Western Desert, Iraq

Three species belong to the genus Convolvulus L. from the Convolvulaceae family, new to Flora of Western Desert District were recorded. These species were Convolvulus cantabrica L., Convolvulus reticulatus Choisy and Convolvulus stachydifolius Choisy. Species were photographed, their taxonomical and ecological characters, as well as their geographical distribution in the Western Desert were demonstrated. Plant samples were collected, precisely identified, dried and herbarium specimens were prepared and deposited at Anbar University Herbarium (AUH). Some notes on habitat, flowering and fruiting periods were provided. The means and reasons that helped these species to be distributed in new places within the Western Desert District of Iraq were realistically discussed, it was found that there was no sample of the three mentioned species that were collected from the Western Desert District at all.


Introduction
Nature and distribution of the wild plant species in the desert region were irregular during successive years for several reasons, in some places of dry nature and solid soils that are surrounded by scattered rocks, the vegetation is usually poor, while we find it dense in other places such as valleys and flat lands, which is covered by rain water and torrents necessary for germination and growth. From here it becomes clear that some environmental role in the distribution of natural vegetation, such as the quality of the soil, the topography of the region, its climate and most importantly, the amounts of rain that vary between years [1].
Based on vegetation characteristics and topography, Iraq lands were divided into four physiographic regions and seventeen districts ( Figure 1). The western desert is the largest district of the desert region, the height of the land above sea level within this district varies widely, greatly, ranging from 25 meters at Razzazah lake in the east to 885meters at Jabal Aniaza in the west, this district equal about 30% of the total area of Iraq [2]. Modern studies on vegetation, plant biodiversity and species distribution for this district are very few or rare. Convolvulaceae is one of the plant families found in Iraq, which includes about 1600 species belonging to 56 genera over the world [3].
Convolvulus L. the second largest genus of Convolvulaceae family, has more than 250 species distributed in the temperate and tropical regions of the world [4], in Europe [5] there are 23 species of the genus Convolvulus, while present about 57 species of the genus in Iran [6]. According to [7], the probable center of diversity for Convolvulus is in South-Eastern Asia (Iraq, Iran and Turkey) owing to the presence of the largest number of species. In the Flora of Turkey and East Aegean Islands, there were 32 species [8]. In Iraq, Zohary [9] mentioned 11 species, while Rechinger [10] indicated that there are 10 species distributed in the Lowland of Iraq, as for Al-Rawi's bulletin [11], it included 15 species distributed in all Iraqi district, this was followed by the Bulletin of Ridda and Daood [12], which depended on the herbarium specimens in the Iraqi National Herbarium and included 18 species belonging to the genus Convolvulus. There is no real number of the species belonging to the mentioned genus, because the seventh volume of Iraqi Flora of the Convolvulaceae family has not been published. As for the last study [13] of this family more than two decades ago, it indicated that there were 18 species belonging to Convolvulus in Iraq. Objective of this study was to know the new distribution of some plant species in this district, in order to give a clear idea of plant biodiversity and identify new species in the region.

Materials and Methods
More than eight field trips were carried out to different zones in the Western Desert District in Iraq during the spring of 2019, such as Al-Rutba region and its surroundings, the highway between Iraq, Syria and Jordan, Al-Nikhaib road to Saudi Arabia and the 160 km. west of Ramadi area, Haditha, Heet, Fallujah and Habbaniyah areas, for collecting and counting the new plant species in this district. Plant samples were collected and then dried and preserved in the Herbarium of Anbar University.
Species were field photographed, focusing on the distinguishing organs of each species. The nature of the habitat and the location of the species were determined, as well as environmental notes were recorded in the field. A Map of the species distribution was also drawn ( Figure 2). Specimens were identified based on [6]and [8,13,14].

3.3.2.
Habitat. Clay soils, agricultural fields, river banks, small canals in small canals in date palm orchards and under trees and under trees, sometimes it grows with fields of Hordeum vulgare. Altitude: 30-100m. . Flowering between late April and early June, fruiting between late May and mid -July.  After reviewing the plant samples of the genus Convolvulus preserved at the Herbaria of Iraqi Universities as well as the Iraqi National Herbarium, it was found that there was no sample of the three mentioned species that were collected from the Western Desert District at all. This work was preceded by a review of all scientific references related to the species, foremost of which is the Al-Aidani study [13] of the genus Convolvulus in Iraq in 1998, as well as the Ridda and Daoud Bulletin [12] issued in 1982, and the previous references such as the Al-Rawi Bulletin [11] in 1964 and the Zohary Bulletin [9] in 1950 and others, none of them indicated the presence of the three species in this district. In addition, recent studies that have been concerned with this province were reviewed, including the study [15] of plant biodiversity for the Al-Rutba Dam area in western desert of Iraq in 2018, and the study [16] of Al-Feadah conservation on the Al-Emsad Valley, south of Al-Rutba region, as they did not mention the existence of these species.

Distribution in Western
It had been doubted that Convovulus cantabrica was recorded in Iraq [10], as for the species Convolvulus reticulatus, it was mentioned in the southeast of Mandali region within the Persian Foothills District, and in the Tikrit region within the Lower Jazira Disrict, as well as presence in Tuz Khurmatu region within Kirkuk District , he did not mention anything about the Western Desert. As for the last species Convolvulus stachydifolius, it was mentioned in Jabal Hamrin within Ghurfa-Adhaim District, and Mandali region to Naft Khaneh, as well as the Badra region within the Eastern Alluvial Plain District. Moreover, it was mentioned that same species were thrived on the banks of the Tigris river within Upper Jazera District, south of Al-Qayara region. t is derived from geographical Furthermore, environmental factors such as winds and dust storms play a role in the migration of species to new environments that may succeed or fail depending on the new conditions, according to field studies and scientific references [17]and [18,19]. Al-Katib [20] mentioned that the prevalence of plants occurs continuously, at any moment there is a real migration in very large numbers, and these migrations represent a new extension of new lands. Among the similar studies that confirmed the continuous spreading process is the recording of six new plant species in Basra district [21]. As well as recording new species in the country, such as Salvia sclareopsis, which belongs to the Lamiaceae family [22], and the species Tephrosia nubica of Papilionaceae family [23].

Conclusion
Wild plant species suffer from environmental instability as a result of new climatic changes. In addition to human intervention in the nature of the geographical distribution of species by unintentionally transferring seeds to new places. These three species have succeeded through their presence in several places in the Western Desert Province. Field studies and surveys remain very important and necessary over time. Appearance of these new species will contribute in increase plant biodiversity in this vital region.