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 ''Internat ...
at the rank of
subclass.
Because some hamamelidid members bear
aments
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated ( anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged ...
(''i.e.'',
catkins
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged c ...
), 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
A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...
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
*: order
Urticales
Urticales is an order of flowering plants. Before molecular phylogenetics became an important part of plant taxonomy, Urticales was recognized in many, perhaps even most, systems of plant classification, with some variations in circumscription. A ...
*: 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 ...
*: 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 ...
*: order
Fagales
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
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 syste ...
. 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 Gr ...
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
* ...
of order but places most of the taxa involved in the
rosids
The rosids are members of a large clade (monophyletic group) of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms.
The clade is divided into 16 to 20 orders, depending upon circumscription and classificati ...
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 vegeta ...
.
References
Historically recognized angiosperm taxa
Plant subclasses
{{angiosperm-stub