Exbucklandia

Last updated

Exbucklandia
Exbucklandia populnea 2.jpg
Exbucklandia populnea
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Saxifragales
Family: Hamamelidaceae
Subfamily: Exbucklandioideae
H.T.Chang
Genus: Exbucklandia
R.W.Br.
Type species
Exbucklandia populnea
Species

Exbucklandia populnea
Exbucklandia tonkinensis
Exbucklandia longipetala

Contents

Exbucklandia is a genus of flowering plants in the family Hamamelidaceae. [1] They are medium to large trees whose natural range is from eastern India through southern China and southward through the Malay Peninsula. [2] In India and China, they are widely cultivated for their impressive foliage and valuable lumber. [3] A few have been grown in the southernmost parts of the United States. [4] To speakers of English, Exbucklandia is generally known as the Pipli tree, from the Bengali name for the species Exbucklandia populnea .

Cultivation

Propagation is usually by seed, but cuttings have been successful under favorable conditions. Plantations of the young trees must be fenced against cattle and deer which eat whatever leaves they can reach. If Exbucklandia is grown in the open, the trunk forks and branches are retained close to the ground. In the forest, where it usually grows, the trunk is single, straight, and free of branches for 9 to 18 metres. Saplings grow slowly for the first few years, then more quickly later on.

Species

Only three species names have ever been published in Exbucklandia. These are Exbucklandia populnea , Exbucklandia tonkinensis , and Exbucklandia longipetala . [5] The specific epithets refer to poplars, Tonkin, and long petals.

Exbucklandia populnea is found throughout the entire range of the genus. Exbucklandia tonkinensis is native to southeastern China, Laos, and northern Vietnam. Exbucklandia longipetala has a much more restricted range, being known only from the Guangxi and Guizhou provinces of China. [6]

Further field work will be needed to determine whether these are three distinct entities and whether the specimens assigned to Exbucklandia populnea represent a single species or two. [1] Consequently, estimates of the number of species range from two [7] to four. [6]

Description

The following description of Exbucklandia applies only to extant species and does not necessarily hold for species known only from the fossil record. It is adapted from the description in Flora of China volume 9, with the exceptions noted.

Exbucklandias are evergreen trees. Exbucklandia populnea and Exbucklandia tonkinensis are usually 16 to 20 meters in height, occasionally reaching 30 meters. The largest known individual of Exbucklandia populnea grew to 45 meters in the Darjeeling Hills of India. [3] The usual height of Exbucklandia longipetala is not known. The twigs have conspicuous nodes.

The leaves are attractively reddish when immature. They are arranged alternately on the stems, an arrangement unusual for Hamamelidaceae. [1] The petioles are long and the leaves flutter in even a light breeze, like the leaves of poplars. The poplar petiole is flattened, and in cross section, it is long in the vertical direction. Whether Exbucklandia has the same sort of petiole has not been recorded.

The leaf blade is simple, and sometimes has three pointed lobes, or rarely, five. It is thickly leathery and its margin is entire. The venation is palmate, with the secondary veins radiating from the apex of the petiole. The stipules are large and coherent; soon falling away.

Each inflorescence has 7 to 16 flowers and is located in the axil of a leaf. The flowers are small and bisexual. Sepals are completely lacking. Petals are often absent, but are small and white when present. Some authors have interpreted what appear to be petals as petaloid staminodes. [1]

The stamens are 10 to 15 in number. The anthers are basifixed, as in all of Hamamelidaceae. Each theca has one sporangium, whereas for most angiosperms, there are two. The thecae open by one valve.

The ovary is half-inferior and, as in the rest of the family, consists of two carpels. The number of ovules in each carpel has been reported as five or six [6] and as six to eight. [1] What some authors have loosely called styles are actually styluli. These are separate by definition, channeling the pollen tubes that invade them into only one carpel. Each stigma is somewhat decurrent down one side of its stylulus.

The fruit is a 4-valved capsule. The two locules separate, and each splits into two valves. Each locule contains five to seven seeds. The upper four or five are sterile and wingless. The lowest one or two are fertile and narrowly winged. The seeds are light and can travel far in a strong wind. [3]

Affinities

Exbucklandia oregonensis Exbucklandia oregonensis as Ficus washingtonensis USNM P36980 img3.jpg
Exbucklandia oregonensis

The phylogeny of Hamamelidaceae has not been resolved with much certainty, but in one recent molecular phylogenetic study, Exbucklandia and Rhodoleia formed the most basal clade in the family. [8] Chunia bucklandioides , a rare tree from Hainan which has never been sampled for DNA, might also be a member of this clade. Vegetatively, it is hard to distinguish from Exbucklandia, while florally, it is intermediate between Exbucklandia and Mytilaria . [9] The morphology of Chunia indicates that if it is not in the clade with Exbucklandia and Rhodoleia, then it either forms its own clade or it is sister to Mytilaria.

Evolution

Exbucklandia was once more widely distributed than it is today. Four species are known only from fossils. [2] Exbucklandia oregonensis grew in the northwestern United States during the Oligocene and Miocene epochs. [10] [11] Exbucklandia microdictya is known from Paleocene deposits near Altay City in Xinjiang, China. Exbucklandia miocenica is a Miocene species from Yunnan, China. Exbucklandia tengchongensis is known from fossils recovered from a diatomite mine in Tengchong County in Yunnan, China. It dates from the Pliocene epoch.

History

In 1825, the name Bucklandia was published for a fossil cycad in the "Tentamen" part of Flora der Vorwelt, the classic paleobotanical work by Kaspar Maria von Sternberg. The name has been attributed to Carl Borivoj Presl as well as to Sternberg. [12] In 1836, Robert Brown, unaware that the name had already been taken, published the name Bucklandia populnea for the living species now known as Exbucklandia populnea [13] to honor the Reverend William Buckland, an English geologist and paleontologist. [14] In the case of Bucklandia, Brown did not meet the requirements of valid publication, but the name was validated by William Griffith, posthumously, in 1847. [15] In 1924, Paul Henri Lecomte named a second species, Bucklandia tonkinensis. [16] For more than 100 years, it remained unnoticed that two genera of plants had received the name Bucklandia. This conflict was finally resolved by Roland W. Brown in 1946. At that time, Brown wrote, "Inasmuch as the 1825 cycadeoid name has priority, the witchhazel genus requires a new name. For this purpose, I propose Exbucklandia, the derivation of which is obvious." [12] Unaware of Brown's paper, Cornelis G.G.J. van Steenis sought to resolve the conflict of names in 1952 by replacing Bucklandia with Symingtonia. [17] He published a notice of this oversight in 1954, acknowledging the priority of Exbucklandia over Symingtonia. [18] In that paper, van Steenis transferred the second species to Exbucklandia, because Roland Brown had not explicitly done so in 1946. Thus van Steenis originated the combination Exbucklandia tonkinensis, but not validly, because he failed to cite the publication of the basionym as the ICBN has required since 1953. In 1959, Hung-Ta Chang validly made the combination Exbucklandia tonkinensis. [19] In that same paper, Chang described and named the third species, Exbucklandia longipetala. A taxonomic history and a description of each of the three species can be found in Flora of China volume 9. [6]

Related Research Articles

<span class="mw-page-title-main">Polygonaceae</span> Knotweed family of flowering plants

The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is based on the genus Polygonum, and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name may refer to the many swollen nodes the stems of some species have, being derived from Greek [poly meaning 'many' and gony meaning 'knee' or 'joint']. Alternatively, it may have a different origin, meaning 'many seeds'.

<span class="mw-page-title-main">Saxifragales</span> Order of Eudicot flowering plants in the Superrosid clade

Saxifragales is an order of angiosperms, or flowering plants, containing 15 botanical families and around 100 genera, with nearly 2,500 species. Of the 15 families, many are small, with eight of them being monotypic. The largest family is the Crassulaceae (stonecrops), a diverse group of mostly succulent plants, with about 35 genera. Saxifragales are found worldwide, primarily in temperate to subtropical zones, rarely being encountered growing wild in the tropics; however, many species are now cultivated throughout the world as knowledge of plant husbandry has improved. They can be found in a wide variety of environments, from deserts to fully aquatic habitats, with species adapted to alpine, forested or fully-aquatic habitats. Many are epiphytic or lithophytic, growing on exposed cliff faces, on trees or on rocks, and not requiring a highly organic or nutrient-dense substrate to thrive.

<i>Tabebuia</i> Genus of flowering plants

Tabebuia is a genus of flowering plants in the family Bignoniaceae. Tabebuia consists almost entirely of trees, but a few are often large shrubs. A few species produce timber, but the genus is mostly known for those that are cultivated as flowering trees.

<span class="mw-page-title-main">Platanaceae</span> Family of flowering plants

Platanaceae, the plane family, is a family of flowering plants in the order Proteales. The family consists of only a single extant genus Platanus, with twelve known species. The plants are tall trees, native to temperate and subtropical regions of the Northern Hemisphere. The hybrid London plane is widely planted in cities worldwide.

<span class="mw-page-title-main">Bignoniaceae</span> Family of flowering plants

Bignoniaceae is a family of flowering plants in the order Lamiales commonly known as the bignonias or trumpet vines. It is not known to which of the other families in the order it is most closely related.

<span class="mw-page-title-main">Hamamelidaceae</span> Witch-hazel, a shrub or small tree

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 system, the Cronquist system, recognized Hamamelidaceae in the Hamamelidales order.

<span class="mw-page-title-main">Canellaceae</span> Family of flowering plants

The Canellaceae are a family of flowering plants in the order Canellales. The order includes only one other family, the Winteraceae. Canellaceae is native to the Afrotropical and Neotropical realms. They are small to medium trees, rarely shrubs, evergreen and aromatic. The flowers and fruit are often red.

<span class="mw-page-title-main">Marantaceae</span> Family of flowering plants in the Commelinid order Zingiberales

The Marantaceae are a family, the arrowroot family, of flowering plants consisting of 31 genera and around 530 species, defining it as one of the most species-rich families in its order. Species of this family are found in lowland tropical forests of Africa, Asia, and the Americas. The majority (80%) of the species are found in the American tropics, followed by Asian (11%) and African (9%) tropics. They are commonly called the prayer-plant family and are also known for their unique secondary pollination presentation.

<span class="mw-page-title-main">Ochnaceae</span> Family of flowering plants

Ochnaceae is a family of flowering plants in the order Malpighiales. In the APG III system of classification of flowering plants, Ochnaceae is defined broadly, to include about 550 species, and encompasses what some taxonomists have treated as the separate families Medusagynaceae and Quiinaceae. In a phylogenetic study that was published in 2014, Ochnaceae was recognized in the broad sense, but two works published after APG III have accepted the small families Medusagynaceae and Quiinaceae. These have not been accepted by APG IV (2016).

<i>Mertensia</i> Genus of flowering plants in the borage family Boraginaceae

Mertensia is a genus of flowering plants in the family Boraginaceae. They are perennial herbaceous plants with blue or sometimes white flowers that open from pink-tinged buds. Such a change in flower color is common in Boraginaceae and is caused by an increase of pH in the flower tissue. Mertensia is one of several plants that are commonly called "bluebell". In spite of their common name, the flowers are usually salverform (trumpet-shaped) rather than campanulate (bell-shaped).

<span class="mw-page-title-main">Altingiaceae</span> Family of flowering plants in the order Saxifragales

Altingiaceae is a small family of flowering plants in the order Saxifragales, consisting of wind-pollinated trees that produce hard, woody fruits containing numerous seeds. The fruits have been studied in considerable detail. They naturally occur in Central America, Mexico, eastern North America, the eastern Mediterranean, China, and tropical Asia. They are often cultivated as ornamentals and many produce valuable wood.

<span class="mw-page-title-main">Parnassiaceae</span> Family of flowering plants

Parnassiaceae Gray were a family of flowering plants in the eudicot order Celastrales. The family is not recognized in the APG III system of plant classification. When that system was published in 2009, Parnassiaceae were treated as subfamily Parnassioideae of an expanded family Celastraceae.

<span class="mw-page-title-main">Peridiscaceae</span> Family of flowering plants in the order Saxifragales

Peridiscaceae is a family of flowering plants in the order Saxifragales. Four genera comprise this family: Medusandra, Soyauxia, Peridiscus, and Whittonia., with a total of 12 known species. It has a disjunct distribution, with Peridiscus occurring in Venezuela and northern Brazil, Whittonia in Guyana, Medusandra in Cameroon, and Soyauxia in tropical West Africa. Whittonia is possibly extinct, being known from only one specimen collected below Kaieteur Falls in Guyana. In 2006, archeologists attempted to rediscover it, however, it proved unsuccessful.

<span class="mw-page-title-main">Tofieldiaceae</span> Family of flowering plants

Tofieldiaceae is a family of flowering plants in the monocot order Alismatales. The family is divided into four genera, which together comprise 28 known species. They are small, herbaceous plants, mostly of arctic and subarctic regions, but a few extend further south, and one genus is endemic to northern South America and Florida. Tofieldia pusilla is sometimes grown as an ornamental.

<i>Alangium</i> Genus of flowering plants

Alangium is a small genus of flowering plants. The genus is included either in a broad view of the dogwood family Cornaceae, or as the sole member of its own family Alangiaceae. Alangium has about 40 species, but some of the species boundaries are not entirely clear. The type species for Alangium is Alangium decapetalum, which is now treated as a subspecies of Alangium salviifolium. All of the species are shrubs or small trees, except the liana Alangium kwangsiense. A. chinense, A. platanifolium, and A. salviifolium are known in cultivation.

Reynoldsia is a formerly recognised genus of plants in the ivy family, Araliaceae. In 2003, Kew Gardens published a checklist for Araliaceae, in which eight species were recognized for Reynoldsia: four from Samoa, two from Tahiti, one from the Marquesas, and one from Hawaii. In 2010, a phylogenetic comparison of DNA data showed that Reynoldsia was polyphyletic, consisting of two groups that are not each other's closest relatives. In a companion paper, three of the species were "sunk" into synonymy with others, reducing the number of species to five. All species that were formerly in Reynoldsia are now in Polyscias subgenus Tetraplasandra, a subgenus of 21 species indigenous to Malesia and the Pacific islands.

<span class="mw-page-title-main">Icacinaceae</span> Family of flowering plants

The Icacinaceae, also called the white pear family, are a family of flowering plants, consisting of trees, shrubs, and lianas, primarily of the tropics.

<i>Rhodoleia</i> Genus of plants

Rhodoleia is a genus of plants in the family Hamamelidaceae. Together with its sister genus Exbucklandia, Rhodoleia forms the sister clade to the other 25 genera of Hamamelidaceae. Flowers of Rhodoleia are bird-pollinated. Nectar-foraging birds including Japanese white-eyes and fork-tailed sunbirds, avidly visit the flowers, which they also pollinate in the process.

<span class="mw-page-title-main">Cardiopteridaceae</span> Family of flowering plants

Cardiopteridaceae is a eudicot family of flowering plants. It consists of about 43 species of trees, shrubs, and woody vines, mostly of the tropics, but with a few in temperate regions. It contains six genera, the largest of which is Citronella, with 21 species. The other genera are much smaller.

Chunia bucklandioides is a species of flowering plant belonging to the family Hamamelidaceae. It is a tree native to Hainan and northern Vietnam. It is the sole species in genus Chunia.

References

  1. 1 2 3 4 5 Peter K. Endress. 1993. "Hamamelidaceae". pages 322-331. In: Klaus Kubitzki (editor); Jens G. Rohwer, and Volker Bittrich (volume editors). The Families and Genera of Vascular Plants volume II. Springer-Verlag: Berlin; Heidelberg, Germany. ISBN   978-3-540-55509-4 (Berlin) ISBN   978-0-387-55509-6 (New York)
  2. 1 2 Jingyu Wu, Bainian Sun, Yu-Sheng (Christopher) Liu, Sanping Xie, and Zhicheng Lin. 2009. "A new species of Exbucklandia (Hamamelidaceae) from the Pliocene of China and its paleoclimatic significance". Review of Palaeobotany and Palynology155(1-2):32-41.
  3. 1 2 3 Robert Scott Troupe. 1984. "Exbucklandia". pages 13-19. In: The Silviculture of Indian Trees volume V. (revised and enlarged by H.B. Joshi). Government of India Press.
  4. ↑ Arthur Lee Jacobson. 2009. "Plant of the Month: January 2009". At: Jacobson's Plant of the Month series. (see External links below).
  5. ↑ The International Plant Names Index. "Exbucklandia". (see External links below).
  6. 1 2 3 4 Zhang Zhiyun, Zhang Hongda (Chang Hung-ta), and Peter K. Endress. 2003. "Hamamelidaceae" pages 18-42. In: Wu Zhengyi, Peter H. Raven, and Hong Deyuan (editors). Flora of China volume 9. Science Press: Beijing, China; Missouri Botanical Garden Press: St. Louis, Missouri, USA.
  7. ↑ David J. Mabberley. 2008. Mabberley's Plant-Book. Cambridge University Press: UK. ISBN   978-0-521-82071-4
  8. ↑ Susana Magallón. 2007. "From Fossils to Molecules: Phylogeny and the Core Eudicot Floral Groundplan in Hamamelidoideae (Hamamelidaceae, Saxifragales)". Systematic Botany32(2):317-347.
  9. ↑ Hung-Ta Chang (Hongda Zhang). 1948. "Chunia". page 63. In: "Additions to the Hamamelidaceous flora of China". Sunyatsenia (1-2):63-74.
  10. ↑ Herb Meyer. 1973. "The Oligocene Lyons Flora of northwestern Oregon". The Ore Bin35(3):37-51. (see External links below).
  11. ↑ Kathleen B. Pigg and Wesley C. Wehr. 2002. "Tertiary Flowers, Fruits, and Seeds of Washington State and Adjacent Areas - Part III". Washington Geology30(3-4):3-20. (see External links below).
  12. 1 2 Brown, R.W. (1946). "Alterations in some fossil and living floras". Journal of the Washington Academy of Sciences. 36 (10): 344–355.
  13. ↑ Robert Brown. 1836. Asiatic Researches19(1):95.
  14. ↑ Umberto Quattrocchi. 2000. CRC World Dictionary of Plant Names volume II. CRC Press: Boca Raton; New York; Washington,DC;, USA. London, UK. ISBN   978-0-8493-2676-9 (vol. II). (see External links below).
  15. ↑ William Griffith. 1847. Journals of Travels in Assam Burma Bootan Affghanistan and the Neighbouring Countries (sic). Bishop's College Press: Calcutta. (reprinted 2001. Munshiram Manoharlal Publishers, New Delhi).
  16. ↑ Paul Henri Lecomte. 1924. Bulletin du Muséum d'Histoire Naturelle. Paris. 30:392.
  17. ↑ Cornelis G.G.J. van Steenis. 1952. Acta Botanica Neerlandica 1:443-444.
  18. ↑ Cornelis G.G.J. van Steenis. 1954. page 595. In: "Miscellaneous Botanical Notes VI". Blumea7(3):595-598.
  19. ↑ Hung-Ta Chang. 1959. Acta Scientiarum Naturalium Universitatis Sunyatseni. 1959(2).
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.