The Cornales are an order of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s, early diverging among the

asterids Asterids are a large clade (monophyly, monophyletic group) of flowering plants, composed of 17 Order_(biology), orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked cl ...

, 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

nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

ies.

Taxonomy

In the classification system of Dahlgren the Cornales were in the

superorder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

Corniflorae (also called Cornanae). Under the

APG IV system The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...

, the Cornales order includes these families: *

Cornaceae The Cornaceae are a cosmopolitan family of flowering plants in the order Cornales. The family contains approximately 85 species in two genera, '' Alangium'' and '' Cornus''. They are mostly trees and shrubs, which may be deciduous or evergreen, ...

(the

dogwood ''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods or cornels, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous ...

family) * Curtisiaceae (cape lancewood) * Grubbiaceae (the sillyberry family) *

Hydrangeaceae Hydrangeaceae is a family of flowering plants in the order Cornales, with a wide distribution in Asia and North America, and locally in southeastern Europe. Description The genera are characterised by leaves in opposite pairs (rarely whorled or ...

(the

hydrangea ''Hydrangea'' ( or ) is a genus of more than 70 species of Flowering plant, flowering plants native plant, native to Asia and the Americas. Hydrangea is also used as the common name for the genus; some (particularly ''Hydrangea macrophylla, H. m ...

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 The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

age.

Phylogeny

The Cornales order is sister to the remainder of the large and diverse asterid

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

. 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.Xiang, Q. Y.,

Soltis, D. E. Douglas Soltis is a Distinguished Professor in the Laboratory of Molecular Systematics & Evolutionary Genetics (Soltis lab), Florida Museum of Natural History, and Department of Biology at the University of Florida. His research interests are in ...

, 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. Under the

Cronquist system The Cronquist system is a list of systems of plant taxonomy, taxonomic classification system of angiosperms, flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of ...

, 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. Likely cladogram for Cornales:Based on Figure 11.10 in Molecular data suggest four clades are within the Cornales: ''

Cornus ''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods or cornels, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous ...

- Alangium'', nyssoids-mastixioids, Hydrangeaceae-Loasaceae, and '' Grubbia- Curtisia'', with the Hydrostachyaceae in an uncertain position, possibly basal.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. 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.Eyde, R. H. (1988). Comprehending ''Cornus'' - puzzles and progress in the systematics of the dogwoods. ''Botanical Review'' 54, 233-351. These difficulties in interpreting the systematics of Cornales may represent an early and rapid diversification of the groups within the order.

References

External links

* http://www.britannica.com/EBchecked/topic/137865/Cornales {{Authority control Angiosperm orders