''Orontium'' , sometimes called golden-club, is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of flowering plants in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Araceae The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe (or leaf-like bract). ...

. The single living species in the genus is '' Orontium aquaticum'', while the two other described species, '' Orontium mackii'' and '' Orontium wolfei'', are known from fossils. ''Orontium mackii'' is the geologically oldest species described, with fossils of the species being found in the Jose Creek member of the

McRae Formation The McRae Formation is a geological formation exposed in southern New Mexico whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. Description The formation consist ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...

. The formation is dated to the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...

, possibly the

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interv ...

. The species is noted for having a simpler vein structure in the leaves then is seen in either ''O. wolfei'' or ''O. aquaticum''. Two of the outcrops where the species was found are preserved volcanic ash beds which hosted long-term standing water. However, a third outcrop is that of a well-drained floodplain with no evidence of standing water. This indicates the possibility that ''O. mackii'' was not an obligate

hydrophyte Aquatic plants are plants that have adapted to living in aquatic environments ( saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that ...

. The second fossil species ''O. wolfei'' is from Early to early Middle Eocene rocks in northern

Washington state Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washingto ...

and southern central

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost Provinces and territories of Canada, province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include ...

. In contrast to the subtropical environment which ''O. mackii'' lived in, ''O. wolfei'' inhabited a colder upland environment with temperatures similar to that seen in the northern end of the ''O. aquaticum'' range. ''O. wolfei'' appears to have inhabited swampy areas and marginal regions of upland lakes in the region. The leaves of ''O. wolfei'' show a more complex vein structure than seen in ''O. mackii'' and have a hooded leaf tip similar to ''O. aquaticum''. The living ''O. aquaticum'' is endemic to eastern North America1. Orontium aquaticum Linnaeus
''

Flora of North America The ''Flora of North America North of Mexico'' (usually referred to as ''FNA'') is a multivolume work describing the native plants and naturalized plants of North America North America is a continent in the Northern Hemisphere and a ...

'' and is found growing in ponds, streams, and shallow lakes. It prefers an acidic environment. The leaves are pointed and oval with a water repellent surface. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

is most notable for having an extremely small almost indistinguishable sheath surrounding the spadix. Very early in the flowering this green sheath withers away leaving only the spadix. The flowering occurs in the spring. Native Americans once ate the seeds and rhizome by drying them out and grinding them into a starchy substance. Image:Orontium aquaticum 2 - Buffalo Botanical Gardens.jpg, ''O. aquaticum'' Image:Orontium wolfei 02.jpg, ''O. wolfei''

References

Bibliography

*Bown, Deni (2000). Aroids: Plants of the Arum Family LLUSTRATED Timber Press. {{Taxonbar, from=Q11799321 Araceae genera Orontioideae Extant Maastrichtian first appearances