Numerical analyses of seed morphology and its taxonomic significance in the tribe Nigelleae (Ranunculaceae)

Abstract

We examined the seed morphology of Nigella, Garidella and Komaroffia to aid systematics and taxonomy. The seeds of 21 taxa in 20 species from Mediterranean and West Asian countries were studied using both zoom stereo and scanning electron microscopy (SEM). Principal coordinate analysis (PCoA) and unweighted average linkage analysis (UPGMA) were performed to assess the contribution of seed characters to the taxonomy of the tribe. Representative pictures from zoom stereo microscopy and SEM studies and measurement of seeds are presented. Most studied species showed unique seed surface sculpturing features, and seed shape, size and surface sculpturing separated the studied taxa into five main groups. However, the variation in seed shape and color were found to be in conflict with the generic taxonomy while macromorphological characters were found more congruent with the sectional taxonomy than with the generic taxonomy. Five main types of seed ornamentations – rugulose + striate, granulate, smooth, rugulose and mucronulate – were identified. Patterns in seed micromorphology strongly supported the sectional level taxonomy of Nigella. Two of the three sections of the genus were found to be well differentiated in terms of seed characters. Furthermore, seed morphology alone provide good support to Garidella as a distinct genus, but shows less taxonomic value for Komaroffia.

Nigella Plants – Traditional Uses, Bioactive Phytoconstituents, Preclinical and Clinical Studies

“…It has been commonly divided into three sections viz. Komaroffia , Garidella and Nigella ( Tutin et al, 1972 ; Tamura, 1993 ; Uğurlu Aydın and Dönmez, 2019 ). Section Komaroffia comprises one species ( Nigella integrifolia Regel), section Garidella consists of two species ( Nigella nigellastrum (L.) Willk.…”

Mechanism of the antidiabetic action of Nigella sativa and Thymoquinone: a review

“…NS is an erect, annual flowering herb 20–90 cm tall, is one of the 20 species belonging to the genus Nigella L. (Family Ranunculaceae, Order Ranunculales, Class Magnoliopsida, Division Tracheophyta, Kingdom Plantae), accorded the taxonomic serial number of 506,592 by Integrated Taxonomic Information System (ITIS) ( 69 ), all the species withing this genus having utility as either food or medicine ( 70 ). The black tint of its discoid seeds occurs once they are exposed to air and is the source of many of its colloquial names “Black cumin” ( 71 ), “Black caraway” ( 72 ) “Alkamoun Alaswad” ( 73 ), or Black seed ( 74 ). Pertinent is the distinction between black cumin and black caraway from true cumin and true caraway, the latter two being the seeds of Cuminum cyminium L., and Carum carvi L, respectively, belonging to family Umbellifera ( 72 ).…”

“…Despite the taxonomic impasse of dividing the Nigellae tribe into genera or sections, the consensus splits it into three genera, of which only Nigella is found in South Asia. Komaroffia and Garidella , on the other hand, are common throughout southern Europe and central Asia ( 74 ). NS stands out from the other Nigella spp.…”

Chromosome characterization and genome size in <i>Nigella</i> and <i>Garidella</i> species (Ranunculaceae) with their taxonomic implications

“…Among the taxa, genome size, karyotype structure, and diversification were studied in Nigella sativa and N. damascena (Bennett and Smith 1976;Ghosh and Datta 2006;Shaker et al 2017). Despite the well-known morphology, palynology, and taxonomy of the tribe (Heiss et al 2011;Işık et al 2019;Uğurlu Aydın and Dönmez 2019;Dönmez et al 2021), detailed cytogenetic studies concerning the tribe are rare and mostly restricted to chromosome counts, which are insufficient to understand karyotype characters and their taxonomic implications.…”