''Petenaea cordata'' (from northern Central America) was first described in

Elaeocarpaceae Elaeaocarpaceae is a family of flowering plants. The family contains approximately 615 species of trees and shrubs in 12 genera."Elaeocarpaceae" In: Klaus Kubitzki (ed.). ''The Families and Genera of Vascular Plants'' vol. VI. Springer-Verlag: Be ...

and later placed in

Tiliaceae Tiliaceae () is a family of flowering plants. It is not a part of the APG, APG II and APG III classifications, being sunk in Malvaceae mostly as the subfamilies Tilioideae, Brownlowioideae and Grewioideae, but has an extensive historical record o ...

, but most authors have been uncertain about its familial affinities. It was considered a taxon ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' in the Angiosperm Phylogeny Group classification (

APG III APG is an abbreviation with several different meanings: * Aberdeen Proving Ground, a United States Army installation in Aberdeen, Maryland, also ** Phillips Army Airfield, the airfield of the above, from its IATA airport code * Aboriginal Provisiona ...

). Molecular analyses based on a recent collection from Guatemala indicate a distant, weakly supported sister-group relationship to the African genus ''Gerrardina'' (

Gerrardinaceae ''Gerrardina'' is a genus of two species of trees, shrubs, and scrambling shrubs found in southeastern Africa. Until recently, the genus was placed in the polyphyletic family Flacourtiaceae, but it was abnormal there due to its apical placentatio ...

;

Huerteales Huerteales is the botanical name for an order of flowering plants.Peter F. Stevens (2001 onwards). "Huerteales". In: Angiosperm Phylogeny Website. In: Missouri Botanical Garden Website. (see ''External links'' below) It is one of the 17 orders th ...

). As no obvious

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

exist for ''Gerrardina'' and ''Petenaea'', the new monogeneric family Petenaeaceae was proposed. The polymorphic order

now comprises four small families:

Dipentodontaceae ''Dipentodontaceae'' is a family of flowering plants containing two genera. # ''Dipentodon'' Dunn - southern China, Assam, Myanmar # ''Perrottetia'' Kunth in F.W.H.von Humboldt - southern China, Southeast Asia, Papuasia, Queensland, Hawaii, Lati ...

, Petenaeaceae and

Tapisciaceae Tapisciaceae is a family of flowering plants. Until recently it had been abandoned by taxonomists, and it was not recognised in the APG II system of 2003. In the APG III system, however, it has been reinstated to encompass the two genera '' Tapis ...

. ''Petenaea cordata'' is the only species in the genus ''Petenaea''.

Description

Trees to c. 10 m, or large shrubs. Stems often tinged red, villous-tomentose. Leaves minutely stipulate; petioles 5–11 cm, densely short villous, red; blades 8.5-15.5 × 6.5-14.5 cm, chartaceous, densely villous below, glabrescent above, turning red with age, palmately veined at base with 5-7 primary veins, the secondary venation reticulate, the base broadly cordate, the margins minutely denticulate, the apices acute to broadly short-acuminate. Stipules minute, soon caducous. Inflorescences axillary, cymose, long-pedunculate, rose-pink, the branches villous-tomentose; pedicels 5–12 mm, pink. Flowers with the sepals c. 4 mm, valvate, lanceolate, attenuate from the base to the apex, reflexed, reddish pink, the base bearing 2-3 obovoid subsessile glands, and densely villous with hairs c. 2 mm, moniliform, pink; petals absent; disc annular, glandular; stamens 8-12, glabrous, the anthers yellow, opening by an apical pore-like slit; ovary superior, sessile, tomentose; style slender; stigma discoid. Berry 6–12 mm, shallowly 4-5 lobed, ovoid to subglobose, pulpy, sweet, sparsely pubescent; seeds numerous, c. 1 mm, oblong-pyramidal or irregular. Flowering and fruiting continuously.

Distribution

Endemic to northern

Mesoamerica Mesoamerica is a historical region and cultural area in southern North America and most of Central America. It extends from approximately central Mexico through Belize, Guatemala, El Salvador, Honduras, Nicaragua, and northern Costa Rica. W ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

(

Chiapas Chiapas (; Tzotzil language, Tzotzil and Tzeltal language, Tzeltal: ''Chyapas'' ), officially the Free and Sovereign State of Chiapas ( es, Estado Libre y Soberano de Chiapas), is one of the states that make up the Political divisions of Mexico, ...

Tabasco Tabasco (), officially the Free and Sovereign State of Tabasco ( es, Estado Libre y Soberano de Tabasco), is one of the 32 Federal Entities of Mexico. It is divided into 17 municipalities and its capital city is Villahermosa. It is located in ...

Belize Belize (; bzj, Bileez) is a Caribbean and Central American country on the northeastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a wate ...

Guatemala Guatemala ( ; ), officially the Republic of Guatemala ( es, República de Guatemala, links=no), is a country in Central America. It is bordered to the north and west by Mexico; to the northeast by Belize and the Caribbean; to the east by H ...

( Petén).

References

{{Taxonbar, from=Q4360166 Flora of Central America Flora of Belize Flora of Guatemala Flora of Mexico Huerteales Monotypic rosid genera Taxa named by Maarten J. M. Christenhusz Taxa named by Mark Wayne Chase