Hamamelidaceae, commonly referred to as the witch-hazel family, is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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

Saxifragales Saxifragales is an order (biology), order of flowering plants in the Superrosids, superrosid clade of the eudicots. It contains 15 Families (biology), families and around 100 genera, with nearly 2,500 species. Well-known and economically import ...

. The clade consists of

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s and small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s positioned within the woody clade of the core Saxifragales. An earlier system, 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 ...

, recognized Hamamelidaceae in the Hamamelidales order.

Description

The Hamamelidaceae are distinguishable from other families in the Saxifragales due to the range of floral characteristics that are generally uniform though all genera. Uniform characteristics include

stipules In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). They are primarily found among dicots and rare among monocots. Stipules are considered part of the anatomy ...

borne on stems with leaves often 2-ranked. Genera usually have a two

carpel Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more ...

gynoecium Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

, although some species show variation. Other characteristics include a multicellular stigma, with shallow papillae or ridges.

Anthers

Anther The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

structure and the modes of opening are considered to be one of the most important features in the systematics and evolution of hamamelids. The anthers in Hamamelids are on average shorter than in other families in the Saxifragales. The anther valve openings are unique pleismorphic features that contrast with the simple longitudinal slits of the anthers in the upper Hamamelidae where the pollen is predominantly wind-driven. The three types of anthers found in the Hamamelidaceae are: * Type 1) The theca (or sheath of anther) opens like a window with two wings; a common anther type. * Type 2) There is one valve opening to reveal two pollen sacs. Five genera in the Hamamelidoideae subfamily, confined to the Southern Hemisphere (''Trichcladus'', ''Dicoryphe'', ''Ostrearia'', ''Neostrearia'', ''Noahdendron'') are known to have this anther type. * Type 3) One valve opens a wing of anther tissue towards the center of the flower revealing one pollen sac. The two genera, ''Exbucklandia'' and ''Hamamelis'' are known to have this anther type.

Pollen

Plants of the Hamamelidaceae have sticky

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

, which may have influenced the type of pollination that is seen in this family. Pollination is predominantly via insects or wind. However, the insect-pollinated genus ''Disanthus'' has been known to wind-pollinate (although inefficiently) in the event pollinators do not visit its flowers. The genus ''Rhodoleia'' is unique because it is bird-pollinated. The pollen structure in the lower Hamamelidae is relatively uniform. The pollen patterns are tricolpate with reticulate exines.

Flowers

The petals of the Hamamelidaceae are generally narrow and ribbon-like. The exceptions are the genera ''Corylopsis'' and ''Rhodoleia'', which have spathulate or circular-like petals. The flowers of Hamamelidaceae are mostly bisexual with perianth parts, which mature to fruits arranged in spikes, racemes or nonglobose heads.

Breeding systems

The anemophilous groups within the Hamamelidaceae are often andromonoecious. Self-incompatibility is common, but self-compatibility occurs in some genera such as ''Hamamelis''.

Taxonomy

The fossil record dates from the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

. Hamamelidaceae was established by

Brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining the colors Orange (colour), orange and black. In the ...

in 1818 as the Hamamelideae, including four genera. The

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

relationship of the Hamamelidaceae have been revisited several times since the first comprehensive classification of the family in 1930. This was clarified in 1998 by the

molecular phylogenetic 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 ...

work of the

Angiosperm Phylogeny Group The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disc ...

(APG) which placed the family within the

eudicot The eudicots or eudicotyledons are flowering plants that have two seed leaves (cotyledons) upon germination. The term derives from ''dicotyledon'' (etymologically, ''eu'' = true; ''di'' = two; ''cotyledon'' = seed leaf). Historically, authors h ...

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

. In doing so, it separated one of the existing subfamilies, the Altingioideae, which formed the basal group, into its own family within the order, the

Altingiaceae Altingiaceae is a small Family (biology), family of flowering plants in the Order (biology), order Saxifragales,Peter F. Stevens (2001 onwards). "Altingiaceae". At: Angiosperm Phylogeny Website. At: Missouri Botanical Garden Website. (see ''Exter ...

Subdivision

Subfamilies

The infrafamilial classification of the Hamamelidaceae has been controversial, and has undergone a number of revisions based on morphology, the best known of which are those of Harms (1930) and Endress (1989). Morphological and

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

studies have supported

monophyly In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent comm ...

of the Hamamelidoideae and have recognized the separation of the Rhodoleioideae and Disanthoideae subfamily and newly erected Mytilarioideae. The relationships between Exbucklandioideae and the other subfamilies have proven controversial. The unresolved monophyly of Exbucklandioideae and the clades of Disanthoideae, Rhodoleioideae, Exbucklandioideae or even Mytilarioideae being a sister clade to Hamamelidoideae may have been a result of differing DNA methodologies researchers have used to produce phylogenetic trees and the inclusion or exclusion of certain genera used as outgroups in their analyses. However, the sister relationship of Disanthoideae and Hamamelidoideae has been well supported, although some researchers do not support this. Strong support for making Altingioideae a family has been recognized by textbooks and the

. Research continues to resolve the deep relationships of the subfamilies within the Hamamelidaceae by incorporating whole or fragmentary fossil evidence. Hamamelidaceae contains 27-30 genera and 80-140 species distributed among five to six subfamilies. The subfamilies are Exbucklandioideae, Rhodoleioideae, Mytilarioideae, Disanthoideae, Hamamelidoideae, and Altingioideae, which has been elevated to a family

in some recent treatments.Judd, W.S., Campbell, C.S., Kellogg, E.A., Stevens, P.F. & Donoghue, M.J. 2010. "Plant Systematics: A Phylogenetic Approach, 3rd ed.". In ds. ''Plant Systematics: A Phylogenetic Approach, 3rd ed''. In ds. Sinauer Associates, Inc., Massachusetts. Many of the subfamilies are

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

and the majority of the species lie within the Hamamelidoideae, which has 22 genera. The long-standing question of whether Altingioideae should be a separate family has been assessed and supported by morphological and

studies.Takhtajan, A. 1997. "Diversity and classification of flowering plants". In ds. ''Diversity and classification of flowering plants''. Columbia University Press, New York. The resulting subfamilial structure was eventually resolved in a series of molecular studies in the late 1990s, resulting in five distinct subfamilies, the majority of the genera residing in the nominative subfamily, Hamamelidoideae: ;Subfamilies (number of genera) * Exbucklandioideae (1 genus; '' Exbucklandia'') * Rhodoleioideae (1 genus; '' Rhodoleia'') * Mytilarioideae (2 genera; '' Mytilaria'', '' Chunia'') * Disanthoideae (1 genus; '' Disanthus'') * Hamamelidoideae (22 genera; see Tribes below)

Tribes

The relatively large size of subfamily Hamamelidoideae and its further subdivision into tribes has also been a matter of study and controversy. Six tribes are now recognized. The revised structure has greatly reduced Hamamelideae to a monotypic taxon, which had previously been further divided into subtribes: * Corylopsideae (1 genus; '' Corylopsis'') * Dicorypheae (5 genera; '' Dicoryphe'', '' Trichocladus'', '' Neostrearia'', '' Noahdendron'', '' Ostrearia'') * Eustigmateae (4 genera; '' Eustigma'', '' Fortunearia'', '' Sinowilsonia'', '' Molinadendron'') * Fothergilleae (7 genera; '' Fothergilla'', '' Parrotiopsis'', '' Parrotia'', '' Shaniodendron'', ''

Sycopsis ''Sycopsis'' is a genus of plants in the family Hamamelidaceae native to southern central China and Taiwan. Characteristics ''Sycopsis'' are evergreen or semi-evergreen shrubs or small trees. Their leaves are leathery and their flowers have no p ...

'', '' Distylium'', '' Distyliopsis'') * Hamamelideae (1 genus; ''

Hamamelis Witch-hazels or witch hazels (''Hamamelis'') are a genus of flowering plants in the family Hamamelidaceae, with three species in North America ('' H. ovalis'', '' H. virginiana'', and '' H. vernalis''), and one each in Japan ('' H.&n ...

'') * Loropetaleae (4 genera; '' Loropetalum'' (including ''Tetrathyrium''), '' Maingaya'', '' Embolanthera'', '' Matudaea'')

Genera

*'' Chunia'' (1 species;

Hainan Hainan is an island provinces of China, province and the southernmost province of China. It consists of the eponymous Hainan Island and various smaller islands in the South China Sea under the province's administration. The name literally mean ...

) *'' Corylopsis'' (winter-hazel; about 30 species; east

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

) *'' Dicoryphe'' *'' Disanthus'' (1 species; east Asia) *'' Distyliopsis'' *'' Distylium'' (about 10 species;

east Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...

, Himalayas) *'' Embolanthera'' *'' Eustigma'' *'' Exbucklandia'' (3 species;

Assam Assam (, , ) is a state in Northeast India, northeastern India, south of the eastern Himalayas along the Brahmaputra Valley, Brahmaputra and Barak River valleys. Assam covers an area of . It is the second largest state in Northeast India, nor ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

, southeast Asia) *'' Fortunearia'' (1 species; eastern

) *'' Fothergilla'' (fothergilla; 3 species; southeastern

U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

) *''

'' (witch-hazel; 4 species; eastern

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, east

) *†'' Langeria'' ( Wolfe) & Wehr)

1 species *'' Loropetalum'' (three species; east Asia) *'' Maingaya'' *'' Matudaea'' *'' Molinadendron'' *'' Mytilaria'' *'' Neostrearia'' *'' Noahdendron'' *'' Ostrearia'' *'' Parrotia'' (Ironwoods; 2 species; disjunct in southwest

and eastern

) *'' Parrotiopsis'' (1 species;

Himalaya The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than 100 pea ...

) *'' Rhodoleia'' (about 7 species; southeast Asia) *'' Sinowilsonia'' (1 species; western China) *''

'' (about 7 species; southeast Asia) *'' Tetrathyrium'' *'' Trichocladus''

Distribution and habitat

The Hamamelidaceae were widely distributed in the Northern Hemisphere during the

Upper 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 ''cret ...

and early

Tertiary Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to: * Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago * Tertiary (chemistry), a term describing bonding patterns in organic ch ...

Quaternary glaciation The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial period, glacial and interglacial, interglacial periods during the Quaternary period that began 2.58 Year#SI prefix multipliers, Ma (million ...

across the Northern Hemisphere caused the extinction of numerous species and the restricted distribution of others. Hamamelidaceae were obliterated from Europe along with numerous other

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

of plants that were unable to escape the ice sheets due to geography (the Mediterranean Sea and Alps forming barriers that did not exist in North America and Asia). The largest subfamily, the Hamamelidoideae, is now distributed in

and western and eastern Asia. The Hamamelidoideae subtribe Dicoryphinae is now restricted to the African (including

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

and Comores) and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n continents. Disanthoideae and Rhodoleioideae are now restricted to southern China and the Caucasus region. Mytilarioideae is restricted to eastern Asia. Altingioideae is now restricted to eastern Asia and western Asia and North America between central

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

and

Belize Belize is a country on the north-eastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a maritime boundary with Honduras to the southeast. P ...

References

Bibliography

Books and theses

* * * * * *

Articles

* * * * * * * * * ;APG * * * *

Websites

* * (''see also'' Angiosperm Phylogeny Website) * *
Hamamelidaceae
i
L. Watson and M.J. Dallwitz (1992 onwards). The families of flowering plants.
{{Authority control Saxifragales families