Cornales

The Cornales are an order of flowering plants, early diverging among the asterids, containing about 600 species. Plants within the Cornales usually have four-parted flowers, drupaceous fruits, and inferior to half-inferior gynoecia topped with disc-shaped nectaries.

Taxonomy

In the classification system of Dahlgren the Cornales were in the superorder Corniflorae (also called Cornanae). Under the APG IV system, the Cornales order includes these families:<ref name=APGIV>Template:Cite journal</ref>

• Cornaceae (the dogwood family)
• Curtisiaceae (cape lancewood)
• Grubbiaceae (the sillyberry family)
• Hydrangeaceae (the hydrangea family)
• Hydrostachyaceae
• Loasaceae (the stickleaf family)
• Nyssaceae, (the tupelos)

The oldest fossils assigned with confidence to the order are Hironoia fusiformis, described from Coniacian age Japanese coalified fruits, and Suciacarpa starrii described from American permineralized fruits of Campanian age.<ref name="Atkinson2016">Template:Cite journal</ref>

Phylogeny

The Cornales order is sister to the remainder of the large and diverse asterid clade. The Cornales are highly geographically disjunct and morphologically diverse, which has led to considerable confusion regarding the proper circumscription of the groups within the order and the relationships between them.<ref name=Xiang1993>Xiang, Q. Y., Soltis, D. E., Morgan, D. R., and Soltis, P. S. (1993). Phylogenetic relationships of Cornus L sensu lato and putative relatives inferred from rbcL sequence data. Annals of the Missouri Botanical Garden 80, 723-734.</ref> Under the Cronquist system, the order comprised the families Cornaceae, Nyssaceae, Garryaceae, and Alangiaceae, and was placed among the Rosidae, but this interpretation is no longer followed. Many families and genera previously associated with the Cornales have been removed, including Garryaceae, Griselinia, Corokia, and Kaliphora, among others.<ref name="Xiang1993" />

Likely cladogram for Cornales:<ref>Based on Figure 11.10 in Template:Cite book</ref> Template:Clade

Molecular data suggest four clades are within the Cornales: Cornus-Alangium, nyssoids-mastixioids, Hydrangeaceae-Loasaceae, and Grubbia-Curtisia, with the Hydrostachyaceae in an uncertain position, possibly basal.<ref name=Fan2003>Fan, C. Z., and Xiang, Q. Y. (2003). Phylogenetic analyses of Cornales based on 26S rRNA and combined 26S rDNA-matK-rbcL sequence data. American Journal of Botany 90, 1357-1372.</ref> However, the relationship between these clades is unclear, and as a result of many historical taxonomic interpretations and differing opinions regarding the significance of morphological variations, rankings of taxa within the order are inconsistent.<ref name=Xiang1993 /><ref name=Fan2003 /><ref name=Eyde1988>Eyde, R. H. (1988). Comprehending Cornus - puzzles and progress in the systematics of the dogwoods. Botanical Review 54, 233-351.</ref> These difficulties in interpreting the systematics of Cornales may represent an early and rapid diversification of the groups within the order.<ref name=Fan2003 />

External links

• http://www.britannica.com/EBchecked/topic/137865/Cornales