Medusandra | |
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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.
The Dioscoreales are an order of monocotyledonous flowering plants in modern classification systems, such as the Angiosperm Phylogeny Group and the Angiosperm Phylogeny Web. Within the monocots Dioscoreales are grouped in the lilioid monocots where they are in a sister group relationship with the Pandanales. The Dioscoreales must contain the family Dioscoreaceae which includes the yam (Dioscorea) which is an important food source in many regions. Older systems tended to place all lilioid monocots with reticulate veined leaves in Dioscoreales. As currently circumscribed by phylogenetic analysis using combined morphology and molecular methods, Dioscreales contains many reticulate veined vines in Dioscoraceae, it also includes the myco-heterotrophic Burmanniaceae and the autotrophic Nartheciaceae. The order consists of three families, 22 genera and about 850 species.
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 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 derivation, meaning 'many seeds'.
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.
Melanthiaceae, also called the bunchflower family, is a family of flowering herbaceous perennial plants native to the Northern Hemisphere. Along with many other lilioid monocots, early authors considered members of this family to belong to the family Liliaceae, in part because both their sepals and petals closely resemble each other and are often large and showy like those of lilies, while some more recent taxonomists have placed them in a family Trilliaceae. The most authoritative modern treatment, however, the APG III system of 2009, places the family in the order Liliales, in the clade monocots. Circumscribed in this way, the family includes up to 17 genera.
Hemerocallidoideae is the a subfamily of flowering plants, part of the family Asphodelaceae sensu lato in the monocot order Asparagales according to the APG system of 2016. Earlier classification systems treated the group as a separate family, the Hemerocallidaceae. The name is derived from the generic name of the type genus, Hemerocallis. The largest genera in the group are Dianella, Hemerocallis (15), and Caesia (11).
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.
Phyllanthaceae is a family of flowering plants in the eudicot order Malpighiales. It is most closely related to the family Picrodendraceae.
Achariaceae is a family of flowering plants consisting of 32-33 genera with about 155 species of tropical herbs, shrubs, and trees. The APG IV system has greatly expanded the scope of the family by including many genera previously classified in Flacourtiaceae. Molecular data strongly support the inclusion of this family in the order Malpighiales.
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.
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.
The Balanophoraceae are a subtropical to tropical family of obligate parasitic flowering plants, notable for their unusual development and formerly obscure affinities. In the broadest circumscription, the family consists of 16 genera. Alternatively, three genera may be split off into the segregate family Mystropetalaceae.
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 flowering plant family in the order Celastrales. It contains only two genera, each with a single 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".
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.