A Study on the Winged Accrescent Sepals of the Chenopodiaceae

The aim of the present study is to examine winged accrescent sepals in the Chenopodiaceae and determine diagnostic characteristics that lead to their discrimination and possibly of taxonomic significance. Nine species belonging to six genera of the family Chenopodiaceae (Subfamily Salsoloideae, Tribe Salsoleae) were dissected, examined, photographed and line illustrated. Seven qualitative and two quantitative characters were investigated. These characters include orientation, symmetry, position with respect to sepals, shape, plane, colour, indumentums, length and width of wings. The present study showed that these wings share several common features, but the diagnostically distinct characteristics of Anabasis setifera, Salsola cyclophylla and S. imbricata were noticed. These distinct wing features were supported by molecular data which suggested their transfer to different genera. These wing characteristics provided further insights into their possible use to reassess the taxonomy of the Chenopodiaceae.


Introduction:
Winged accrescent sepals are persistent sepals (calyces, perianth) that grow beyond anthesis with membranous wings on their dorsal sides (Saxena 2010). These wings may be regarded as an adaptation enhancing wind dispersal of the seeds (Jurado et al. 1991), and their presence may affect various physiological behaviors (Bhatt et  Chenopodiaceae is a family of about 100 genera and 1500 species worldwide, especially in desert and semi-desert regions (Welsh et al. 2003). According to Kadereit et al. (2003), Chenopodiaceae was divided into seven Subfamilies. Within these Subfamilies, winged accrescent sepals were encountered in three Subfamilies, five Tribes and 26 genera (El Ghazali 2018).
Winged accrescent sepals within the Chenopodiaceae, although may be considered as important characters for species delimitation (Sukhorukov 2007), and provide support for the taxonomic implication of DNA-based phylogeny (Cabrera et al. 2009), scarce information is available in literature on their characteristic features (Pratt 2003). The aim of the present study is to examine quantitative and qualitative morphological variations of the wings accrescent sepals in various members of the Chenopodiaceae and determine diagnostic characteristics that lead to their discrimination and possibly of taxonomic significance.

Material and Methods
Nine species belonging to six genera of family Chenopodiaceae/ Amaranthaceae, Subfamily Salsoloideae (Tribe Salsoleae) collected from Qassim Region (Saudi Arabia) were examined. These are

Results
A total number of seven qualitative (table 1) and two quantitative characters were examined. The qualitative characters examined include orientation, symmetry, position of wings with respect to sepals, shape, plane, colour and surface indumentums, whereas the quantitative characters include the length and width of the wings. The fruiting branches, the intact and detached wings of the species examined are photographed and line illustrated (Figs. 1, 2 and 3).
The nine species examined share several common features. The orientation of the wings are vertical in Anabasis setifera, and horizontal in the rest of the species examined. Actinomorphic symmetry was noticed in seven species and zygomorphism in two species. The wings are inserted above the middle in A. setifera, below the middle in Salsola cyclophylla, and inserted at the middle of the dorsal side of the sepals in seven species. The shape, plane and colour of the wings varied widely within the species examined, whereas the densely pubescent indumentums present on the surfaces of the wings are characteristic of only Salsola cyclophylla (Table 1).
Winged accrescent sepals of the genus Salsola are represented by four species in the present study. All the species are characterized by horizontal and twisted wings, but they have different shapes and colours. Out of these four species, Salsola imbricata exhibits a peculiar zygomorphic symmetry (Fig. 2 C).
The size of the largest wings (length X width) within the studied species vary from (6.0 X 4.4) mm in  Table 1. Qualitative characters of the wings present dorsally on the sepals of various members of the Chenopodiaceae (Actino-= Actinomorphic, zygo-= zgyomorphic, y-w = yellowish white, Y-G = yellowish green, Y = yellowish, G-Y = greenish yellow, S-Y = straw yellow, W = whitish, P = pinkish, G = glabrous, Pu = pubescent).

Discussion and conclusions
Winged accrescent sepals occur in scattered plant families (Bryophytes, gymnosperms and angiosperms), but are particularly abundant in family Chenopodiaceae (El Ghazali 2018). In the present study, nine species belonging to six genera of the subfamily Salsoloideae (Tribe Salsoleae) were examined. These nine species share several common features, but the unique characteristics of Anabasis setifera, Salsola cyclophylla and S. imbricata are outstanding.
Winged accrescent sepals of A. setifera is quite distinct from all the species examined. It is the only species with vertical orientation, and are inserted above the middle of the dorsal side of the sepals. Using morphological (Akhani et al. 1997 In the present study, four species belonging to the genus Salsola were examined. The wings of S. cyclophylla and S. imbricata are distinct and their position in the genus should be revised. Salsola cyclophylla is the only species out of the nine species examined with the wings inserted below the middle of the dorsal sides of the sepals and with dense pubescent indumentums on their surfaces. According to Kapralov et al. (2006), the genus Salsola belongs to Tribe Salsoleae. Akhani et al.