Variation in seed morphology in the genus Erica L. (Ericaceae)

Abstract

Abstract:Seed morphology was studied in 136 species of Erica, including 123 from South Africa (Cape Floristic Region), 5 from tropical Africa, and 8 from Europe. Seed anatomy was studied in 13 selected species by light and scanning electron microscopy. Seed morphology of each species was described and documented by SEM micrographs. Ten major diagnostic features were selected, concerning seed shape, primary sculpture, and fine relief. On the basis of these features, the species were divided into 14 groups. Within them, 40 morphologically homogeneous subgroups were distinguished, which could possibly be used in future revisions of the genus. A key to species identification has been developed on the basis of seed characteristics. A very close similarity was observed between seeds of some Erica species from distant parts of the distribution range of this genus.

Description and systematic affinity of flower and seed fossils of Erica sect. Chlorocodon (Ericaceae) from the early Pleistocene of Madeira Island, Portugal

“…The morphology of seeds of extant European and Macaronesian Erica species was studied in the last decades, revealing their taxonomical value (Huckerby & al., 1972; Fagúndez & Izco, 2003, 2009, 2010, 2011; Szkudlarz, 2009; Fagúndez & al., 2010). The Madeiran seed fossils fit within the WPBH seed size and morphology and undoubtedly differ from other species currently growing in Madeira (i.e., E. arborea s.l.…”

“…Flower identification was achieved by comparing it to herbarium material (Appendix 1) and to the literature (McClintock, 1989, 1994; Nelson, 2009, 2011). SEM images of seed fossils were compared with extant SEM images of Macaronesian and mainland seeds (Fagúndez & Izco, 2003, 2009, 2010; Szkudlarz, 2009). Flower description follows the nomenclature given by Menezes de Sequeira (1997), while seed description follows Szkudlarz (2009) and Fagúndez & Izco (2003).…”

“…SEM images of seed fossils were compared with extant SEM images of Macaronesian and mainland seeds (Fagúndez & Izco, 2003, 2009, 2010; Szkudlarz, 2009). Flower description follows the nomenclature given by Menezes de Sequeira (1997), while seed description follows Szkudlarz (2009) and Fagúndez & Izco (2003). Open nomenclature follows the proposal by Bengtson (1988).…”

Taxonomic importance of seed morphology of Veronica L. subsect. Agrestes Benth. (Plantaginaceae)

“…Many authors highlighted the systematic value of the structural form of the seed coat due to its low phenetic variation of the species (e.g. : Barthlott 1981;Elisens & Tomb 1983;Martinez-Ortega & Rico 2001;Muñoz-Centeno et al 2006, 2007Szkudlarz 2009;Szkudlarz & Celka 2016). The use of SEM made it possible to determine general types of seed coat sculpturing.…”

“…Fruit and seed traits play a significant role in the taxonomy of many species (Stace 1989;Szkudlarz 2009;Davitashvili & Karrer 2010;Szkudlarz & Celka 2016). The morphology and micromorphology of seeds are often utilised for taxonomic purposes also in Plantaginaceae and related families, like Scrophulariaceae or Orobanchaceae (e.g.…”