Gunnera Temporal range: Late Cretaceous - present, | |
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Gunnera tinctoria at the San Francisco Botanical Garden at Strybing Arboretum | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Gunnerales |
Family: | Gunneraceae Meisn. [1] |
Genus: | Gunnera L. |
The range of the genus Gunnera [2] | |
Synonyms [3] | |
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Gunnera is the sole genus of herbaceous flowering plants in the family Gunneraceae, which contains 63 species. Some species in this genus, namely those in the subgenus Panke, have extremely large leaves. Species in the genus are variously native to Latin America, Australia, New Zealand, Papuasia, Hawaii, insular Southeast Asia, Africa, and Madagascar. [3] The stalks of some species are edible. [4]
Gunnera is the only genus in the family Gunneraceae. [5] The APG II system, of 2003, also recognizes this family and assigns it to the order Gunnerales in the clade core eudicots. The family then consisted of one or two genera, Gunnera and, optionally, Myrothamnus , the latter optionally segregated as a separate family, Myrothamnaceae. This represents a change from the APG system, of 1998, which firmly recognized two separate families, unplaced as to order. The APG III system and APG IV system recognizes the family Gunneraceae and places Myrothamnus in Myrothamnaceae; both families are placed in the order Gunnerales in the core eudicots. [6]
The genus Gunnera was named after the Norwegian botanist Johann Ernst Gunnerus. At first it was assigned to the family Haloragaceae, though that presented difficulties that led to the general recognition of the family Gunneraceae, as had been proposed about the beginning of the 20th century. In the meantime, in many publications it had been referred to as being in the Haloragaceae, variously misspelt (as for example "Halorrhagidaceae". [7] ) Such references still cause difficulties in consulting earlier works. However, currently Gunnera is firmly assigned to the monogeneric family Gunneraceae. [8]
Gunnera is thought to be a rather ancient group, with a well-documented fossil history due to the presence of fossilized pollen spores, known by the palynotaxon Tricolpites reticulatus . It is a Gondwanan lineage, having originated in South America during the Cretaceous. The earliest fossilized pollen is known from the Late Cretaceous (Turonian) of Peru, about 90 million years ago, and within the following 10 million years, Gunnera had achieved a worldwide distribution, with fossil pollen grains being found in areas where it is not found today, such as western North America, mainland Australia, and Antarctica. [9] [10] Based on fossil pollen recovered from drilling cores, Gunnera is also known to have inhabited the now-submerged islands of the Ninetyeast Ridge during the Paleocene, likely having dispersed there from either Australasia or the then-emergent Kerguelen Plateau islands. [11]
Due to the widespread distribution of Gunnera during the Cretaceous, it was previously thought that the modern disjunct distribution of the genus was a relic of this period. However, phylogenetic analysis indicates that the majority of Gunnera species, even those found on entirely different continents, diverged from each other during the Cenozoic, indicating that the modern distribution of Gunnera is a consequence of long-distance dispersal from South America to other parts of the world, rather than relics of a former cosmopolitan distribution. The only species that diverged prior to the Cenozoic is Gunnera herteri of southeastern Brazil, which is thought to be the most ancient species of the genus, its lineage having diverged during the Late Cretaceous, roughly concurrent with the oldest Gunnera fossil pollen from Peru. The persistence of the Gunnera crown group since the Cretaceous makes it unique among flowering plants, and may have been facilitated by strong niche conservatism, dispersal ability, and being able to aggressively colonize disturbed land. [10]
The 40–50 species vary enormously in leaf size, with the iconic large-leaved species belonging to the subgenus Panke. The giant rhubarb, or Campos des Loges ( Gunnera manicata ), native to the Serra do Mar mountains of southeastern Brazil, is perhaps the largest species, with reniform or sub-reniform leaves typically 1.5 to 2.0 meters (4 ft 11 in to 6 ft 7 in) long, not including the thick, succulent petiole which may be up to 2.5 meters (8 feet 2 inches) in length. The width of the leaf blade is typically 2.5 meters (8 feet 2 inches), but on two occasions cultivated specimens (in Dorset, England in 2011 [12] and at Narrowwater, Ulster, Ireland [13] in 1903) produced leaves fully 3.3 meters (10 feet 10 inches) in width. The seeds germinate best in very moist, but not wet, conditions and temperatures of 22–29 °C.
Only slightly smaller is G. masafuerae of the Juan Fernandez Islands off the Chilean coast. They can have leaves up to 2.9 m (9 ft 6 in) in width on stout leaf stalks 1.5 m (4 ft 11 in) long and 11 cm (4+1⁄2 in) thick according to Skottsberg. [14] These leafstalks or petioles are the thickest of any dicot, and probably also the most massive. On nearby Isla Más Afuera, G. peltata frequently has an upright trunk to 5.5 m (18 ft 1 in) in height by 25–30 cm (10–12 in) thick, bearing leaves up to 2 m (6 ft 7 in) wide. The Hoja de Pantano (G. magnifica) of the Colombian Andes bears the largest leaf buds of any plant; up to 60 cm (2 ft) long and 40 cm (16 in) thick. [15] The succulent leaf stalks are up to 2.7 m (8 ft 10 in) long. The massive inflorescence of small, reddish flowers is up to 2.3 m (7 ft 7 in) long and weighs about 13 kg. The flowers of Gunnera species are dimerous ( two sepals, two petals (or none) . two stamens (or one), and two carpels. [16] Other giant Gunnera species within the subgenus Panke are found throughout the Neotropics and Hawaii. Gunnera insignis is also known by the name "poor man's umbrella" in Costa Rica.
Outside of the subgenus Panke, most of the more basal Gunnera species have small-to-medium-sized leaves. There are some species with moderately large leaves in Africa (G. perpensa, in the subgenus Perpensum) and Southeast Asia (G. macrophylla, in the subgenus Pseudogunnera), but the majority of more basal species are low-lying, mat-forming plants with small leaves. There are several small species are found in New Zealand, notably G. albocarpa, with leaves only 1–2 cm long, and also in South America, with G. magellanica having leaves 5–9 cm wide on stalks 8–15 cm long. The most basal species in the genus, G. herteri of Brazil, also has small leaves. [17] [18]
Some fossil leaf impressions of Gunnera from the Cretaceous of North America have large leaves akin to those of Panke, and the most basal extant species within Panke (G. mexicana) is the most northern member. For this reason, it has been suggested that Panke originates from South American Gunnera that colonized North America during the Cretaceous and grew into giant forms, with the remaining South American Gunnera evolving into the subgenus Misandra, with a low-lying, matlike growth. During the Cenozoic, the North American Panke would have colonized Hawaii and retreated southwards on the mainland before recolonizing South America. However, more recent phylogenetic evidence suggests that Misandra and Panke diverged only 15 million years ago, much too recent to assign the Cretaceous Gunnera to Panke. Due to this, the large-leaved Cretaceous Gunnera from North America may represent a distinct lineage that convergently evolved giant leaves similar to those of Panke, but did not leave any descendants. [10] [17] [19]
As of April 2023 [update] , Plants of the World Online accepts the following species [20] separated by subgenus: [21]
Subgenus | Image | Scientific name | Distribution |
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OstenigunneraMattfeld, 1933 | Gunnera herteri Osten | Uruguay, S Brazil | |
PseudogunneraSchindler, 1905 | Gunnera macrophylla Blume | Papuasia, Indonesia, Philippines | |
MilliganiaSchindler, 1905 | Gunnera albocarpa (Kirk) Cockayne | New Zealand | |
Gunnera arenaria Cheeseman ex Kirk | New Zealand | ||
Gunnera cordifolia (Hook.f.) Hook.f. | Tasmania | ||
Gunnera densiflora Hook.f. | New Zealand | ||
Gunnera dentata Kirk | New Zealand | ||
Gunnera flavida Colenso | New Zealand | ||
Gunnera hamiltonii Kirk ex W.S.Ham. | New Zealand | ||
Gunnera mixta Kirk | New Zealand | ||
Gunnera monoica Raoul | New Zealand incl Chatham Islands | ||
Gunnera prorepens Hook.f. | New Zealand | ||
Gunnera reniformis Ridl. | New Guinea | ||
Gunnera strigosa (Kirk) Colenso | New Zealand | ||
PankeSchindler, 1905 | Gunnera aequatoriensis L.E.Mora | Ecuador | |
Gunnera annae Schindl. | Peru, Bolivia | ||
Gunnera antioquensis L.E.Mora | Colombia | ||
Gunnera apiculata Schindl. | Bolivia, Argentina | ||
Gunnera atropurpurea L.E.Mora | Colombia, Ecuador | ||
Gunnera berteroi Phil. | Bolivia, Argentina, Chile | ||
Gunnera bogotana L.E.Mora | Colombia | ||
Gunnera bolivari J.F.Macbr. | Peru, Ecuador | ||
Gunnera boliviana Morong | Bolivia | ||
Gunnera bracteata Steud. ex Benn. | Robinson Crusoe Island in Chile | ||
Gunnera brephogea Linden & André | Colombia, Ecuador, Peru | ||
Gunnera caucana L.E.Mora | Colombia | ||
Gunnera colombiana L.E.Mora | Colombia, Ecuador | ||
Gunnera × cryptica J.M.H.Shaw (G. manicata × G. tinctoria) | Cultivated | ||
Gunnera cuatrecasasii L.E.Mora | Colombia | ||
Gunnera diazii L.E.Mora | Colombia | ||
Gunnera garciae-barrigae L.E.Mora | Colombia | ||
Gunnera hernandezii L.E.Mora | Colombia | ||
Gunnera insignis (Oerst.) Oerst. | Panama, Nicaragua, Costa Rica | ||
Gunnera × katherine-wilsoniae L.D.Gómez (G. insignis × G. talamancana) | Costa Rica | ||
Gunnera kauaiensis Rock | Kauai in Hawaii | ||
Gunnera killipiana Lundell | Chiapas, Guatemala, Honduras | ||
Gunnera lozanoi L.E.Mora | Colombia | ||
Gunnera magnifica H.St.John | Colombia | ||
Gunnera manicata Linden ex André | S Brazil | ||
Gunnera margaretae Schindl. | Peru, Bolivia | ||
Gunnera masafuerae Skottsb. | Alejandro Selkirk Island (Isla Mas Afuera) in Chile | ||
Gunnera mexicana Brandegee | Veracruz, Chiapas | ||
Gunnera morae Wanntorp & Klack. | Colombia | ||
Gunnera peltata Phil. | Robinson Crusoe Island in Chile | ||
Gunnera peruviana J.F.Macbr. | Ecuador, Peru | ||
Gunnera petaloidea Gaudich. | Hawaii | ||
Gunnera pilosa Kunth | Peru, Bolivia, Ecuador | ||
Gunnera pittieriana V.M.Badillo & Steyerm. | Venezuela | ||
Gunnera quitoensis L.E.Mora | Ecuador | ||
Gunnera saint-johnii (L.E.Mora) L.E.Mora | Colombia | ||
Gunnera sanctae-marthae L.E.Mora | Colombia | ||
Gunnera schindleri L.E.Mora | Bolivia, Argentina | ||
Gunnera schultesii L.E.Mora | Colombia | ||
Gunnera silvioana L.E.Mora | Ecuador, Colombia | ||
Gunnera steyermarkii L.E.Mora | Venezuela | ||
Gunnera tacueyana L.E.Mora | Colombia | ||
Gunnera tajumbina L.E.Mora | Ecuador, Colombia | ||
Gunnera talamancana H.Weber & L.E.Mora | Costa Rica, Panama | ||
Gunnera tamanensis L.E.Mora | Colombia | ||
Gunnera tayrona L.E.Mora | Colombia | ||
Gunnera tinctoria (Molina) Mirb. | Chile, Argentina | ||
Gunnera venezolana L.E.Mora | Venezuela | ||
MisandraSchindler, 1905 | Gunnera magellanica Lam. | W + S South America, Falkland Is. | |
Gunnera lobata Hook.f. | Tierra del Fuego | ||
Gunnera | Gunnera perpensa L. | Africa, Madagascar | |
In 2022, it was shown that plants in cultivation under the name Gunnera manicata were actually a hybrid, Gunnera × cryptica. [22]
At least some species of Gunnera host endosymbiotic cyanobacteria such as Nostoc punctiforme . The cyanobacteria provide fixed nitrogen to the plant, while the plant provides fixed carbon to the microbe. [23] The bacteria enter the plant via glands found at the base of each leaf stalk [2] and initiate an intracellular symbiosis which is thought to provide the plant with fixed nitrogen in return for fixed carbon for the bacterium. The Nostoc filled symbiotic tissue makes up just a small portion of the plant's total biomass. Gunnera is the only known genus of angiosperms that hosts cyanobacteria, and the only known landplants with intracellular cyanobionts. Although the endosymbionts enters the cell wall, they do not penetrate the cell membrane. [24] [25] This relationship may provide insights to allow the creation of novel symbioses between crop plants and cyanobacteria, allowing growth in areas lacking fixed nitrogen in the soil.
The stalks of G. tinctoria (nalca), from southern Chile and Argentina, are edible. [4] Their principal use is fresh consumption, after peeling, but also they are prepared in salads, liquor or marmalade. Leaves of this species are used in covering curanto (a traditional Chilean food).
Gunnera perpensa is a source of traditional medicine in southern Africa, both in veterinary and human ailments, largely in obstetric and digestive complaints, but also as a wound dressing. [7] It also is eaten in various ways, largely the petioles, flower stalks and leaves, fresh and raw, preferably with skins and fibre removed, which is said to remove bitterness, but also cooked. The plant also is said to be used in making a beer. [26]
The Nymphaeales are an order of flowering plants, consisting of three families of aquatic plants, the Hydatellaceae, the Cabombaceae, and the Nymphaeaceae. It is one of the three orders of basal angiosperms, an early-diverging grade of flowering plants. At least 10 morphological characters unite the Nymphaeales. One of the traits is the absence of a vascular cambium, which is required to produce both xylem (wood) and phloem, which therefore are missing. Molecular synapomorphies are also known.
The Elaeagnaceae are a plant family, the oleaster family, of the order Rosales comprising small trees and shrubs, native to temperate regions of the Northern Hemisphere, south into tropical Asia and Australia. The family has about 60 species in three genera.
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly and live very long. Because of their superficial resemblance, they are sometimes mistaken for palms or ferns, but they are not closely related to either group.
The Aristolochiaceae are a family, the birthwort family, of flowering plants with seven genera and about 400 known species belonging to the order Piperales. The type genus is Aristolochia L.
Droseraceae is a family of carnivorous flowering plants, also known as the sundew family. It consists of approximately 180 species in three extant genera. Representatives of the Droseraceae are found on all continents except Antarctica.
The Gunnerales are an order of flowering plants. In the APG III (2009) and APG IV systems (2016), the order contains two genera: Gunnera and Myrothamnus (Myrothamnaceae). In the Cronquist system (1981), the Gunneraceae were in the Haloragales and Myrothamnaceae in the Hamamelidales. DNA analysis proved definitive, but the grouping of the two families was a surprise, given their very dissimilar morphologies. In the older systems of Cronquist and Takhtajan (1997), the Gunneraceae were in the Rosidae, and the Myrothamnaceae were in the Hamamelids. In modern classification systems, such as APG III and APG IV, this order was the first to derive from the core eudicots.
The Typhaceae are a family of flowering plants, sometimes called the cattail family. The botanical name for the family has been recognized by most taxonomists.
Winteraceae is a primitive family of tropical trees and shrubs including 93 species in five genera. It is of particular interest because it is such a primitive angiosperm family, distantly related to Magnoliaceae, though it has a much more southern distribution. Plants in this family grow mostly in the southern hemisphere, and have been found in tropical to temperate climate regions of Malesia, Oceania, eastern Australia, New Zealand, Madagascar and the Neotropics, with most of the genera concentrated in Australasia and Malesia. The five genera, Takhtajania, Tasmannia, Drimys, Pseudowintera, and Zygogynum s.l. all have distinct geographic extant populations. Takhtajania includes a single species, T. perrieri, endemic only to Madagascar, Tasmannia has the largest distribution of genera in Winteraceae with species across the Philippines, Borneo, New Guinea, Eastern Australia, and Tasmannia, Drimys is found in the Neotropical realm, from southern Mexico to the subarctic forests of southern South America, Pseudowintera is found only in New Zealand, and Zygogynum has species in New Guinea and New Caledonia.
Coriaria is the sole genus in the family Coriariaceae, which was described by Linnaeus in 1753. It includes 14 species of small trees, shrubs and subshrubs, with a widespread but disjunct distribution across warm temperate regions of the world, occurring as far apart as the Mediterranean region, southern and eastern Asia, New Zealand, the Pacific Ocean islands, and Central and South America.
Chloranthaceae is a family of flowering plants (angiosperms), the only family in the order Chloranthales. It is not closely related to any other family of flowering plants, and is among the early-diverging lineages in the angiosperms. They are woody or weakly woody plants occurring in Southeast Asia, the Pacific, Madagascar, Central and South America, and the West Indies. The family consists of four extant genera, totalling about 77 known species according to Christenhusz and Byng in 2016. Some species are used in traditional medicine. The type genus is Chloranthus. The fossil record of the family, mostly represented by pollen such as Clavatipollenites, extends back to the dawn of the history of flowering plants in the Early Cretaceous, and has been found on all continents.
The Cabombaceae are a family of aquatic, herbaceous flowering plants. A common name for its species is water shield. The family is recognised as distinct in the Angiosperm Phylogeny Group IV system (2016). The family consists of two genera of aquatic plants, Brasenia and Cabomba, totalling six species.
Myrothamnus is a genus of flowering plants, consisting of two species of small xerophytic shrubs, in the southern parts of tropical Africa and in Madagascar. Myrothamnus is recognized as the only genus in the family Myrothamnaceae.
The Cyrillaceae are a small family of flowering plants in the order Ericales, native to warm temperate to tropical regions of the Americas. The family comprises two genera, Cliftonia and Cyrilla, each containing a single species, Cliftonia monophylla and Cyrilla racemiflora. However, additional species of Cyrilla are now often recognized and the genus is in need of taxonomic revision.
Haloragaceae is a eudicot flowering plant family in the order Saxifragales, based on the phylogenetic APG system. In the Cronquist system, it was included in the order Haloragales.
Aphloia is a genus of flowering plants that contains a single species, Aphloia theiformis, the sole species of the monogeneric family Aphloiaceae. It is a species of evergreen shrubs or small trees occurring in East Africa, Madagascar, the Mascarene Islands and the Seychelles.
Gunnera manicata, known as Brazilian giant-rhubarb or giant rhubarb, is a species of flowering plant in the family Gunneraceae from the coastal Serra do Mar Mountains of Santa Catarina, Parana and Rio Grande do Sul States, Brazil. In cultivation, the name G. manicata has regularly been wrongly applied to the hybrid with G. tinctoria, G. × cryptica.
Iteaceae is a flowering plant family of trees and shrubs native to the eastern USA, southeastern Africa, and south and Southeastern Asia. Some older taxonomic systems place the genus Itea in the family Grossulariaceae. The APG III system of 2009 includes the former Pterostemonaceae in Iteaceae. Consequently, it now has two genera with a total of 18 known species.
Borthwickia is genus of flowering plants, containing one species, Borthwickia trifoliata from Yunnan, China and Myanmar. The common name in Chinese is 节蒴木. It is a shrub or small tree with evergreen trifoliate leaves, whitish flowers clustered at the tip of the branches, with many stamens, and thin, knobbly, drooping fruits with many small red seeds.
Gunnera × cryptica is a hybrid between Gunnera manicata and Gunnera tinctoria. Both species were introduced into cultivation in Western Europe towards the end of the 19th century. The hybrid occurred spontaneously in cultivation, in Europe probably around 1873. Both morphological and molecular analyses have shown that plants widely cultivated in Britain and Ireland under the name Gunnera manicata were all the hybrid, and that the true species G. manicata is no longer found there. This situation may also be the case in Europe and other parts of the world. The hybrid is more resistant to frost and adverse conditions than G. manicata, which is likely to be why it has replaced it in cultivation.
Gunnera cordifolia, often referred to as Tasmanian mudleaf, is an endemic core eudicot of Tasmania, Australia. It is one of 63 species pertaining to the Gunnera genus of herbaceous flowering plants. G. cordifolia can be easily identified by its dark olive-green, heart shaped leaves. It is predominantly found growing in sub-alpine boglands, or in wet grassy areas as a perennial ground cover.