| Chloranthaceae | |
|---|---|
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| Sarcandra glabra | |
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| Chloranthus fortunei | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Order: | Chloranthales R.Br.[2] |
| Family: | Chloranthaceae R.Br. ex Sims[2] |
| Genera | |
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Chloranthaceae is afamily offlowering plants (angiosperms), the only family in theorderChloranthales.[2] 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.[3] Some species are used in traditional medicine. The type genus isChloranthus. The fossil record of the family, mostly represented by pollen such asClavatipollenites, extends back to the dawn of the history of flowering plants in theEarly Cretaceous, and has been found on all continents.[4]
Chloranthaceae arefragrantshrubs orherbaceous plants, that only produce new side branches on the new growth.[further explanation needed] The stems are mostly cylindrical, with solidinternodes, thickenednodes in many species, that carry evergreen leavesarranged in pairs on opposite sides of the stem, withstipules that have merged with that of the opposing leaf. The smallflowers are seated directly on the axis of theinflorescence.Petals are absent in this family, and sometimes so aresepals. The flowers can be either hermaphrodite or of separate sexes. The fruit is adrupe orberry, consisting of onecarpel.[5]
The four genera assigned to this family can be distinguished from each other by the following characters:
Sarcandra species are shrubs whose wood lacksvessels. They havebisexual flowers, with only one, club-shaped,stamen, in which the connective tissue (between theanther lobes which carry the pollen) is wide, and with a smooth and moiststigma. This genus has four species, which occur in Malaysia, China, Indochina, Japan, India, and Sri Lanka.
Chloranthus species are dwarf shrubs orherbaceous plants, withxylem that contains vessels. Flowers are bisexual, each of which bears three stamens on straight filaments with three anther lobes and a wideconnective, and with a smooth and moiststigma. The 20 species occur in southern and eastern Asia.
Ascarina has separate male and female flowers. The male flowers are subtended by twobracts and have between one and five stamens, in which the connective is not widened. The female flower is without bracts, the stigma is dry and covered inpapillae. The fruit is adrupe-likeberry. There are 12 species, which occur on islands in the Pacific and insular South-East Asia, from New Zealand and theMarquesas toBorneo, and onMadagascar.
Hedyosmum has separate male and female flowers. The male flowers are without bracts and have one stamen, in which the connective is not widened. The female flower is without bracts; the stigma is dry and covered inpapillae. Female flowers have a 3-lobedcalyx. The fruit, a drupe, has a kernel with a hard and woody shell. There are 43 species found in Latin America, including theAntilles, as well as one species found in Southeast Asia.
The Chloranthaceae have been recognised as a family in most classifications but without clear relatives.Molecular systematics studies have shown that it is not closely related to any other family and is among theearly-diverging lineages in the angiosperms. In particular, it is neither aeudicot nor amonocot. Fossils assigned to Chloranthaceae, or closely related to the family, are among the oldest angiosperms known.[6][7][8] TheAPG II system (2003) left the family unplaced as to order, but theAPG III system (2009) acceptedChloranthales,containing only this family.[2] The cladogram below, from theAPG IV system (2016), shows the Chloranthales in atrichotomy with themagnoliids and the monocot-Ceratophyllales-dicotclade. Earlier, the order was grouped with magnoliids, but studies in 2014 did not support this placement, leaving its phylogeny unclear.[9] A 2021 study sequenced theChloranthus genome and found Chloranthales as sister to magnoliids.[10]
A 2004 study based on comparisons of homologous DNA fragments indicated that both the family Chloranthaceae and its extant generaAscarina,Chloranthus,Hedyosmum andSarcandra are probablymonophyletic, withHedyosmum being the first to diverge from the rest, andAscarina being thesister group of the clade consisting ofSarcandra andChloranthus. As of June 2016[update], these four extant genera are recognized, and insights into their relationships are expressed in thetree below:[5][11]
| Chloranthaceae | |
The extinct genusChloranthistemon also belongs to this family.[12]
TheCronquist system (1981) assigned the family
TheThorne system (1992) placed it
TheDahlgren system raised the family to be
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