Hamamelididae is an obsolete

botanical name A botanical name is a formal scientific name conforming to the ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) and, if it concerns a plant cultigen, the additional cultivar or Group epithets must conform to the ''Interna ...

at the rank of subclass. Because some hamamelidid members bear aments (''i.e.'', catkins), this subclass has been formerly known as ''Amentiferae''. Based on

molecular phylogeny 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 ...

works, Hamamelididae appears to be a polyphyletic group.Savolainen, V., M. W. Chase, S. B. Hoot, C. M. Morton, D. E. Soltis, C. Bayer, M. F. Fay, A. Y. De Bruijn, S. Sullivan, and Y.-L. Qiu. 2000. Phylogenetics of flowering plants based on combined analysis of plastid ''atpB'' and ''rbcL'' gene sequences. ''Systematic Biology'' 49:306-362. Soltis, D. E. et alii. (28 authors). 2011. "Angiosperm phylogeny: 17 genes, 640 taxa". ''American Journal of Botany'' 98(4):704-730. A well-known system that used the name Hamamelididae is the

Cronquist system The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of Flowering Plants'' (1968; 2nd edition, 1988) ...

, although in the disallowed spelling ''Hamamelidae''. In the original 1981 version of this system the circumscription was: * subclass Hamamelidae *: order Trochodendrales *: order

Hamamelidales Hamamelidales is an order of flowering plants formerly accepted in a number of systems of plant taxonomy, including the Cronquist system published in 1968 and 1988. The order is not currently accepted in the Angiosperm Phylogeny Group III system ...

*: order Daphniphyllales *: order Didymelales *: order

Eucommiales Eucommiales is an order of flowering plants. This order was recognised in the Cronquist system, placed in the subclass Hamamelidae ic as consisting of a single species: ''Eucommia ulmoides ''Eucommia ulmoides'' is a species of small tree na ...

*: order Urticales *: order

Leitneriales ''Leitneria floridana'' (corkwood), the sole species in the genus ''Leitneria'', is a deciduous dioecious shrub or small tree, found only in the southern United States states of Arkansas, Florida, Georgia, Missouri and Texas. It grows at damp h ...

*: order

Juglandales Juglandales is an order of flowering plants. This order was recognised in several systems (e.g. Engler system and Wettstein system). The Cronquist system placed the order in the subclass Hamamelidae, as comprising the families Juglandaceae and ...

*: order

Myricales The Fagales are an order of flowering plants, including some of the best-known trees. The order name is derived from genus ''Fagus'', beeches. They belong among the rosid group of dicotyledons. The families and genera currently included are as ...

*: order Fagales *: order Casuarinales As is true for any botanical name,

circumscription Circumscription may refer to: *Circumscribed circle *Circumscription (logic) *Circumscription (taxonomy) * Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

of the subclass will vary with the taxonomic system being used; the only requirement being that it includes the family

Hamamelidaceae Hamamelidaceae, commonly referred to as the witch-hazel family, is a family of flowering plants in the order Saxifragales. The clade consists of shrubs and small trees positioned within the woody clade of the core Saxifragales. An earlier sy ...

. The

APG II system The APG II system (Angiosperm Phylogeny Group II system) of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Gro ...

does not recognize named taxa above the

rank Rank is the relative position, value, worth, complexity, power, importance, authority, level, etc. of a person or object within a ranking, such as: Level or position in a hierarchical organization * Academic rank * Diplomatic rank * Hierarchy * H ...

of order but places most of the taxa involved in the rosids clade, with Hamamelidaceae itself in order

Saxifragales The Saxifragales (saxifrages) are an order of flowering plants (Angiosperms). They are an extremely diverse group of plants which include trees, shrubs, perennial herbs, succulent and aquatic plants. The degree of diversity in terms of vege ...

References

Historically recognized angiosperm taxa Plant subclasses {{angiosperm-stub