Podostemaceae

Podostemaceae
	Mourera fluviatilis
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Malpighiales
Family:	Podostemaceae; Rich. ex Kunth
Genera
	About 50; see text

Podostemaceae (riverweed family), a family in the order Malpighiales, comprise about 50 genera and c. 300 species^[2] of more or less thalloid aquatic herbs.

Distribution and habitat

They are found mostly in tropical and subtropical areas worldwide.^[3] Many species are found in a very small geographic area, often even just a single river or waterfall.^[4]^[5] Because of their small range, many species are seriously threatened, especially from habitat loss (for example, due to dams flooding their habitat).^[5]^[6]

Riverweeds adhere to hard surfaces (generally rock) in rapids and waterfalls of rivers. They are submerged when water levels are high, but during the dry season they live a terrestrial existence, flowering at this time. Their root anatomy is specialized for the purpose of clinging to rocks, and in fact details of the root structure are one of the ways of classifying riverweeds.^[7]

Ecology

In many rivers, Podostemaceae are an important food source for a wide range of animals. For example, the tadpoles of the African goliath frog (world's largest frog) feed only on Dicraeia warmingii,^[8] and in South America several serrasalmid fish (Mylesinus, Ossubtus, Tometes and Utiaritichthys) mainly feed on Podostemaceae.^[9]

Taxonomy

The Podostemaceae are related to the families Clusiaceae, Hypericaceae (the St. John's wort family, which is sometimes treated as a subfamily of Clusiaceae), and Bonnetiaceae.^[11]^[12] In the classification system of Dahlgren Podostemaceae were placed as a single family in the Podostemales order, which was the only order in the superorder Podostemiflorae (also called Podostemanae).

The family is divided into three subfamilies, Podostemoideae, Trisichoideae, and Weddellinoideae. Trisichoideae is the most basally diverged, and is sister to the other two subfamilies.^[13]

Genera

52 genera are accepted.^[14]

Angolaea Wedd.
Apinagia Tul.
Autana C.T.Philbrick
Castelnavia Tul. & Wedd.
Ceratolacis (Tul.) Wedd.
Cipoia C.T.Philbrick, Novelo & Irgang
Cladopus H.Möller
Ctenobryum Koi & M.Kato
Cussetia M.Kato
Dalzellia Wight
Diamantina Novelo, C.T.Philbrick & Irgang
Dicraeanthus Engl.
Djinga C.Cusset
Endocaulos C.Cusset
Farmeria Willis ex Hook.f.
Hanseniella C.Cusset
Hydrobryum Endl.
Hydrodiscus Koi & M.Kato
Indodalzellia Koi & M.Kato
Indotristicha P.Royen
Inversodicraea Engl. ex R.E.Fr.
Laosia Koi, Won & M.Kato
Lebbiea Cheek^[15]
Ledermanniella Engl.
Leiothylax Warm.
Letestuella G.Taylor
Lophogyne Tul.
Macropodiella Engl.
Marathrum Bonpl.
Mourera Aubl.
Noveloa C.T.Philbrick
Oserya Tul. & Wedd.
Paleodicraeia C.Cusset
Paracladopus M.Kato
Paradalzellia Koi, P.L.Uniyal & M.Kato
Podostemum Michx.
Pohliella Engl.
Polypleurum (Tul.) Warm.
Rhyncholacis Tul.
Saxicolella Engl.
Sphaerothylax Bisch. ex C.Krauss
Stonesia G.Taylor
Terniopsis H.C.Chao
Thawatchaia M.Kato, Koi & Y.Kita
Thelethylax C.Cusset
Tristicha Thouars
Weddellina Tul.
Wettsteiniola Suess.
Willisia Warm.
Winklerella Engl.
Zehnderia C.Cusset
Zeylanidium (Tul.) Engl.

Moved to other families

Hydrostachys from Madagascar. This genus seems to have relatively little in common with any other, and no affinity to the Podostemaceae except being aquatic; moved to its own family in the Cornales.

References

^ Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III" (PDF). Botanical Journal of the Linnean Society. 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. hdl:10654/18083. Retrieved 2013-07-06.
^ Christenhusz, M. J. M.; Byng, J. W. (2016). "The number of known plants species in the world and its annual increase". Phytotaxa. 261 (3): 201–217. doi:10.11646/phytotaxa.261.3.1.
^ Podostemaceae at the Encyclopædia Britannica
^ "Podostemaceae". Institute of Systematic Botany, University of Zurich. Archived from the original on 2007-07-03.
^ ^a ^b Bove, C.P.; C.T. Philbrick (2014). "Rediscovery of a Neotropical rheophyte (Podostemaceae) after 160 years: Implications for the location of conservation unit boundaries (Tocantins, Brazil)". Check List. 10 (5): 1170–1173. doi:10.15560/10.5.1170.
^ Hettiarachchi, K.; S. Daniel (7 August 2011). "Now vital aquatic plants face similar fate as fish". The Sunday Times. Retrieved 4 November 2017.
^ Satoshi Koi; Rieko Fujinami; Namiko Kubo; Ikue Tsukamoto; Rie Inagawa; Ryoko Imaichi; Masahiro Kato (2006). "Comparative anatomy of root meristem and root cap in some species of Podostemaceae and the evolution of root dorsiventrality". American Journal of Botany. 93 (5): 682–692. doi:10.3732/ajb.93.5.682. PMID 21642132.
^ "Conraua goliath". AmphibiaWeb. Retrieved 4 November 2017.
^ van der Sleen, P.; J.S. Albert, eds. (2017). Field Guide to the Fishes of the Amazon, Orinoco, and Guianas. Princeton University Press. pp. 173–196. ISBN 978-0691170749.
^ "Macarenia clavigera" (in Spanish). El Acuario. Archived from the original on 16 April 2021. Retrieved 26 January 2022.
^ Gustafsson, Mats H. G. (2002). "Phylogeny of Clusiaceae Based on rbcL sequences". International Journal of Plant Sciences. 163 (6): 1045–1054. doi:10.1086/342521. JSTOR 3080291. S2CID 85307271.
^ "Malpighiales". Angiosperm Phylogeny Website.
^ Katayama, N., Koi, S., Sassa, A. et al. Elevated mutation rates underlie the evolution of the aquatic plant family Podostemaceae. Communications Biology 5, 75 (2022). https://doi.org/10.1038/s42003-022-03003-w
^ Podostemaceae Rich. ex Kunth. Plants of the World Online. Retrieved 12 April 2024.
^ "Lebbiea (Podostemaceae-Podostemoideae), a new, nearly extinct genus with foliose tepals, in Sierra Leone." Cheek, M. PLOS One, 5 October 2018 (retrieved December 2018)