Ctenanthe

Ctenanthe Eichler is an accepted genus of the family Marantaceae, placed within the order Zingiberales. Plants of the World Online (POWO), maintained by the Royal Botanic Gardens Kew, records the genus as accepted under the authority Eichler, with a native range extending from Costa Rica south through South America [1]. The GBIF Backbone Taxonomy (dataset d7dddbf4-2cf0-4f39-9b2a-bb099caae36c) carries the genus under the same authority, consistent with the POWO treatment, as confirmed on retrieval on 2026-08-12 [2].

Unlike the closely related genus Calathea G.Mey. — the majority of whose species were transferred to Goeppertia Nees under the 2012 revision by Borchsenius, Suárez and Prince — Ctenanthe has remained nomenclaturally stable since its 1884 publication [1]. No subsequent transfer or merger has displaced it, and no mass reclassification of the kind that affected Calathea applies to this genus. Readers arriving from searches on related Marantaceae genera should note that Ctenanthe and its accepted species names are not affected by the Borchsenius et al. revision.

The genus is distinguished from its closest relatives — particularly Stromanthe Sond. — by its characteristically branching stems and long-petioled leaves [1]. The majority of species are concentrated in the Atlantic Forest biome of Brazil, and POWO records the native habitat of the genus as the wet tropical biome [1].

Plants of the World Online circumscribes Ctenanthe Eichler as a genus of 15 accepted species within Marantaceae, with a native range recorded from Argentina Northeast, Bolivia, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Colombia, Costa Rica, Ecuador, Panamá, Paraguay, Peru, Venezuela, and Trinidad-Tobago [1]. This figure was retrieved from POWO in 2025 and is the basis for the registry species estimate of 15. The GBIF Backbone Taxonomy likewise accepts the genus under the Eichler authority [2].

Among the 15 accepted species recorded by POWO are Ctenanthe amabilis (É.Morren) H.Kenn. & Nicolson, Ctenanthe burle-marxii H.Kenn., Ctenanthe compressa (A.Dietr.) Eichler, Ctenanthe kummeriana (É.Morren) Eichler, and Ctenanthe setosa (Roscoe) Eichler [1]. The genus is classified as Neotropical in distribution, with the preponderance of species occurring in Brazil.

A doctoral revision of Ctenanthe and Stromanthe by Yoshida-Arns, submitted to the Universidade Federal de Pernambuco in 2002 under the title Revisão Taxonômica dos gêneros Ctenanthe Eichler e Stromanthe Sond., is cited in the taxonomic literature as a reference treatment for the genus [1]. The full text of that revision has not been retrieved for this article. Limited authoritative sources available; further research needed on the specific diagnostic characters it establishes.

The genus Ctenanthe was established by August Wilhelm Eichler, a German botanist who served as an editor of Flora Brasiliensis, the multi-volume taxonomic treatment of Brazilian plants published between 1840 and 1906. The protologue appeared in 1884 in the Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin at page 81 [1]. Both POWO and the GBIF Backbone Taxonomy confirm Eichler as the accepted authority for the genus name [1][2].

The name has remained stable in the more than 140 years since its publication. No subsequent transfer, merger, or synonymisation has displaced Ctenanthe Eichler as the accepted genus epithet. This contrasts with the situation in the related genus Calathea G.Mey., where Borchsenius, Suárez and Prince published 246 combinations into Goeppertia Nees in 2012 in Systematic Botany 37(3): 620–635 — a revision that does not affect Ctenanthe [1].

Plants of the World Online accepts 15 species within Ctenanthe Eichler as of the 2025 retrieval date [1]. This registry currently holds no seeded species pages for the genus. The absence of species pages does not reflect any disagreement with the POWO circumscription; it reflects the current scope of the registry build. The five species named above — Ctenanthe amabilis, Ctenanthe burle-marxii, Ctenanthe compressa, Ctenanthe kummeriana, and Ctenanthe setosa — are among those accepted by POWO and would be candidates for future species-level pages [1].

The registry holds two cultivar entries, both at the species level of Ctenanthe oppenheimiana: 'Amagris' (documented in U.S. Plant Patent PP14641) and 'VALCOSTA2' (documented in U.S. Plant Patent PP35039) [3][4]. Readers should note that the count of two registry cultivar entries represents a documented subset of whatever cultivar diversity exists within the genus, not a claim that only two cultivars have been named or grown. The patent record is the only prose-admissible primary source available for cultivar identity in this genus at the time of writing.

Two cultivar denominations for Ctenanthe are documented in U.S. plant patents held by this registry. Both are selections within Ctenanthe oppenheimiana and both are described in their respective patents as produced as indoor ornamental plants propagated by division or tissue culture [3][4].

U.S. Plant Patent PP14641, granted on 2004-03-30, names René Denis as inventor and describes the denomination 'Amagris' as a naturally occurring whole-plant mutation of the Ctenanthe oppenheimiana selection known by the epithet 'burle-marxii' (itself not patented), discovered in June 2000 in a controlled environment at Beervelde-Lochristi, Belgium [3]. The patent was assigned to Denis Plants BVBA. PP14641 describes 'Amagris' as characterised by a compact plant habit, a narrow leaf shape, an upper leaf surface of grayed green with dark green margins and venation, and a lower leaf surface of grayed purple — characters used in side-by-side comparisons with the parent selection conducted at the discovery site [3]. As of the access date of 2026-08-12, Google Patents records the status of PP14641 as Expired — Lifetime, consistent with the standard 20-year U.S. plant patent term calculated from the grant date of 2004-03-30 [3].

U.S. Plant Patent PP35039, granted on 2023-03-14, names Oscar Valstar of Maasland, the Netherlands, as inventor and describes the denomination 'VALCOSTA2' as a naturally occurring whole-plant mutation discovered in May 2017 at his commercial greenhouse in Maasland, growing amongst a cultivated population of Ctenanthe oppenheimiana 'Compactstar' (itself not patented) [4]. The patent was assigned to Gebr. Valstar Beheer B.V. in December 2022; the Google Patents automated current-assignee field displays 'Individual' in addition to recording the reassignment transaction to Gebr. Valstar Beheer B.V. in its history — the registry treats the reassignment transaction as the primary record and notes that the 'Individual' display is a known Google Patents display artefact [4]. PP35039 carries the status Active as of the 2026-08-12 access date, with a grant date of 2023-03-14; the application claimed priority to Community Plant Variety Rights application number 2021/2548, filed on 2021-10-11 [4]. The patent describes 'VALCOSTA2' as characterised by large laminae on long, upright petioles arising directly from the base of the plant, a light greyed-green adaxial laminar surface with broad portions prominently coloured with a mixture of dark green to yellow-green, and an abaxial surface coloured with a mixture of dark greyed-purple and brown lightly suffused with yellow-green at the margins [4].

The registry records 'Amagris' and 'VALCOSTA2' each under two name-class rows: one as an accepted epithet and one as a patent denomination. Under the International Code of Nomenclature for Cultivated Plants (ICNCP), a patent denomination and a registered cultivar epithet are distinct name classes even when the character string is identical; neither patent constitutes registration with a formal cultivar registration authority. No trade designations are documented in either patent; attributing a trade name to either patent would not be supported by the primary record.

Beyond the patent descriptions and native-range data, limited authoritative sources available; further research needed on documented cultivation performance from botanic garden or university extension records.

No International Cultivar Registration Authority (ICRA) has been appointed for the family Marantaceae. The International Society for Horticultural Science (ISHS), which coordinates the ICRA system under the International Code of Nomenclature for Cultivated Plants, does not list an appointed authority for Marantaceae [5]. This is the situation for the family as a whole, and it applies to Ctenanthe as one of its genera.

In the absence of an appointed ICRA, there is no formal body that could adjudicate cultivar epithet conflicts within Ctenanthe, maintain a searchable register, or issue registration certificates. The primary documentary evidence for cultivar identity in this genus is therefore limited to U.S. plant patents and Community Plant Variety Rights applications [3][4]. Of these, U.S. plant patents are admissible as prose-citable primary sources under the source hierarchy applied by this registry because they constitute public records with verifiable dates. The CPVR application cited as priority in PP35039 (application number 2021/2548, filed 2021-10-11) is noted in the patent record but has not been retrieved as a primary source for this article [4]. Limited authoritative sources available; further research needed on whether any national or regional body has assumed a de facto registration function for Marantaceae cultivars.

This page is the genus-level orientation entry for Ctenanthe in the Digital Towns plant registry. It establishes the accepted name, the authority, the species count as of a stated retrieval date, and the cultivar record as documented in verifiable primary sources. It links outward to cultivar-level pages where those exist.

Each factual claim in this article carries an inline citation marker corresponding to a numbered source listed below. The source hierarchy for this registry places peer-reviewed taxonomy and botanical garden publications first, followed by GBIF and POWO as corroborating taxonomic backbones, and U.S. plant patents as the primary source for cultivar originator, parentage, discovery date, and diagnostic characters [1][2][3][4]. Catalogue entries, nursery listings, and aggregator sites are not used as prose sources regardless of their prevalence in search results; where such sources are the only evidence for a claim, that claim does not appear in this article.

The registry distinguishes three name classes that are frequently conflated in horticultural writing: a registered cultivar epithet (in single quotes, such as 'Amagris'), a patent denomination (the denomination as stated in the plant patent, which may carry the same string), and a trade designation (a marketing name or trademark, which is a separate category). Where a patent is silent about a trade designation, this registry states that the patent is silent — it does not infer or attribute a trade name from the patent record. Both patents on record for Ctenanthe are silent on trade designations [3][4].

The species pages linked from this hub, where they exist, follow the same citation discipline. The cultivar pages for 'Amagris' and 'VALCOSTA2' are sourced to the respective primary patent records [3][4]. Where a registry row carries the flag verified_against_primary: true, the data has been checked against the primary record rather than derived from a secondary or aggregator source.