The Cornaceae are a cosmopolitan family 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 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, although a few species are perennial herbs. Members of the family usually have opposite or alternate simple leaves, four- or five-parted flowers clustered in

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s or pseudanthia, and drupaceous fruits.Kubitzki, K. (2004). Cornaceae. In ''The Families and Genera of Vascular Plants Volume 6: Flowering Plants: Dicotyledons: Celastrales, Oxidales, Rosales, Cornales, Ericales'' (Kubitzki, ed.). Springer-Verlag, New York. The family is primarily distributed in northern temperate regions and tropical Asia. In northern temperate areas, Cornaceae are well known from the dogwoods '' Cornus''. The

systematics Systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: phylogenetic trees, phylogenies). Phy ...

of Cornaceae has been remarkably unsettled and controversial, and many genera have been added to it and removed from it over time. (One researcher called it a "dustbin".Eyde, R. H. (1988). Comprehending ''Cornus'' - puzzles and progress in the systematics of the dogwoods. ''Botanical Review'' 54, 233-351.)

Molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

have clarified the relatedness of some associated genera, and at least nine genera that were previously included in Cornaceae have been eliminated from the order Cornales entirely,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. but the circumscription of Cornaceae is still unclear. The Angiosperm Phylogeny Group usually defines Cornaceae as comprising the genera '' Cornus'' and '' Alangium'' as well as five genera now separated into the family Nyssaceae. However, many of these genera are sometimes split off into their own families (e.g. Alangiaceae), and the usage remains inconsistent.

Fossil record

The oldest

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

that can be related to Cornaceae is †''Hironoia fusiformis'', an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

taxon collected from the Futaba Group sediments at Kamitikaba,

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. Synapomorphies of the fruits of the fossil occur also in extant Cornaceae. The age of the sediments is of early Coniacian to early

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

(about 88 Ma). Although the mosaic of characters in ''Hironoia'' precludes assignment to an extant genus, the fiber rather than sclereid composition of the fruit places it within the Nyssaceae-Mastixiaceae. Other possible Cornaceae from

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

sediments include

endocarp Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Fruitlike structures may develop directly from the seed itself rather th ...

s resembling Cornus from the

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 ...

mesofossil assemblage of Åsen. In slightly younger

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

sediments (

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

) four genera of

mastixioid fruits (''Beckettia'', ''Eomastixia'', ''Mastixicarpum'' and ''Mastixiopsis'') have been described from

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

References

External links

Cornaceae on the Angiosperm Phylogeny Website of the Missouri Botanical Garden
{{Authority control Asterid families