Medusandra | |
---|---|
Medusandra richardsiana | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Saxifragales |
Family: | Peridiscaceae |
Genus: | Medusandra Brenan |
Type species | |
Medusandra richardsiana | |
Species | |
Medusandra is a genus of flowering plants in the family Peridiscaceae. [1] It has two species, Medusandra richardsiana and Medusandra mpomiana . [2] M. richardsiana is the most common and well known. Both species are native to Cameroon and adjacent countries. [3]
Medusandra was named by John Brenan in 1952. [4] Brenan put Medusandra in its own family, Medusandraceae, and added Soyauxia to that family in 1953. [5] Most authors, however, maintained Medusandraceae as a monogeneric family and put Soyauxia elsewhere. [6] [7] A detailed description of Medusandra was published by John Hutchinson in 1973. [6]
When the APG II system was published by the Angiosperm Phylogeny Group in 2003, Medusandra and Soyauxia were listed in an appendix as "taxa of uncertain position". [8] The first molecular phylogenetic study to include Medusandra appeared in 2009. [9] It showed that Medusandra is sister to a clade consisting of Soyauxia, Peridiscus, and by implication, Whittonia. These three genera are in Peridiscaceae, [10] and the authors, Kenneth Wurdack and Charles Davis, recommended that Medusandra be added to Peridiscaceae. When the APG III system was published in October 2009, Peridiscaceae was expanded to include Medusandra and Soyauxia. [11]
The Alismatales (alismatids) are an order of flowering plants including about 4,500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Perhaps the most important food crop in the order is the taro plant, Colocasia esculenta.
The Malpighiales comprise one of the largest orders of flowering plants, containing about 36 families and more than 16,000 species, about 7.8% of the eudicots. The order is very diverse, containing plants as different as the willow, violet, poinsettia, manchineel, rafflesia and coca plant, and are hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems based only on plant morphology. Molecular clock calculations estimate the origin of stem group Malpighiales at around 100 million years ago (Mya) and the origin of crown group Malpighiales at about 90 Mya.
The Santalales are an order of flowering plants with a cosmopolitan distribution, but heavily concentrated in tropical and subtropical regions. It derives its name from its type genus Santalum (sandalwood). Mistletoe is the common name for a number of parasitic plants within the order.
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 discovered through phylogenetic studies.
Asphodelaceae is a family of flowering plants in the order Asparagales. Such a family has been recognized by most taxonomists, but the circumscription has varied widely. In its current circumscription in the APG IV system, it includes about 40 genera and 900 known species. The type genus is Asphodelus.
Gelsemiaceae is a family of flowering plants, belonging to the order Gentianales. The family contains only three genera: Gelsemium, Mostuea and Pteleocarpa. Gelsemium has three species, one native to Southeast Asia and southern China and two native to Central America, Mexico, and the southeastern United States. The eight species of Mostuea are native to tropical areas of South America, Africa, and Madagascar. The two genera were formerly classified in the family Loganiaceae. Pteleocarpa was originally placed in Boraginaceae or in its own family Pteleocarpaceae, but it is most closely related to Gelsemiaceae with which it shares significant characters.
Phyllanthaceae is a family of flowering plants in the eudicot order Malpighiales. It is most closely related to the family Picrodendraceae.
Samydaceae is a family of tropical and subtropical woody plants, its best known genus being Casearia. It has always been of uncertain placement, in the past usually being submerged in the family Flacourtiaceae.
In the APG IV system (2016) for the classification of flowering plants, the name asterids denotes a clade. Asterids is the largest group of flowering plants, with more than 80,000 species, about a third of the total flowering plant species. Well-known plants in this clade include the common daisy, forget-me-nots, nightshades, the common sunflower, petunias, yacon, morning glory, lettuce, sweet potato, coffee, lavender, lilac, olive, jasmine, honeysuckle, ash tree, teak, snapdragon, sesame, psyllium, garden sage, blueberries, table herbs such as mint, basil, and rosemary, and rainforest trees such as Brazil nut.
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.
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.
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.
Huerteales is the botanical name for an order of flowering plants. It is one of the 17 orders that make up the large eudicot group known as the rosids in the APG III system of plant classification. Within the rosids, it is one of the orders in Malvidae, a group formerly known as eurosids II and now known informally as the malvids. This is true whether Malvidae is circumscribed broadly to include eight orders as in APG III, or more narrowly to include only four orders. Huerteales consists of four small families, Petenaeaceae, Gerrardinaceae, Tapisciaceae, and Dipentodontaceae.
Soyauxia is a genus of flowering plants in the family Peridiscaceae. They are small trees or erect shrubs from wet forests of tropical West Africa. Eight specific names have been published in Soyauxia. Additional species have been discovered, but their names and descriptions will not be published until 2009 or 2010. The type species for the genus is Soyauxia gabonensis.
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.
Lepidobotryaceae is a family of plants in the order Celastrales. It contains only two species: Lepidobotrys staudtii and Ruptiliocarpon caracolito.
Lepuropetalon is a genus of flowering plants in the family Celastraceae. Before it was placed in the family when it was defined by the Angiosperm Phylogeny Group's APG III system in 2009, it had been placed with Parnassia in the family Parnassiaceae, now usually treated as a segregate of Celastraceae. When their most recent revision of Angiosperm classification was published in 2016, it retained its position in the family Celastraceae. Lepuropetalon has only one species, Lepuropetalon spathulatum. It is a winter annual that is most abundant in eastern Texas and western Louisiana. From there, it occurs sporadically southward into Mexico, and eastward through the Atlantic and Gulf coastal plain, and rarely in the Piedmont Plateau, to North Carolina. It has a disjunct distribution. In addition to the area mentioned above, it is also found in Uruguay and central Chile.
When the APG II system of plant classification was published in April 2003, fifteen genera and three families were placed incertae sedis in the angiosperms, and were listed in a section of the appendix entitled "Taxa of uncertain position".
Tetracarpaea is the only genus in the flowering plant family Tetracarpaeaceae. Some taxonomists place it in the family Haloragaceae sensu lato, expanding that family from its traditional circumscription to include Penthorum and Tetracarpaea, and sometimes Aphanopetalum as well.
Peraceae Klotzsch is a family of flowering plants in the eudicot order Malpighiales. The family was segregated from the Euphorbiaceae by Johann Friedrich Klotzsch in 1859, and its uniqueness was affirmed by the Royal Botanic Gardens, Kew's Euphorbiaceae expert, Airy Shaw.