Trimezia Explained

Trimezia is a genus of flowering plants in the family Iridaceae, native to the warmer parts of southern Mexico, Central America, South America, Florida, and the West Indies.[1] Trimezia is placed in the tribe Trimezieae. The division of the tribe into genera has varied considerably. In one approach, it contains only the genus Trimezia, which then includes the genera Neomarica, Pseudotrimezia and Pseudiris. In other approaches, two to five genera are recognized, sometimes also including the genus Deluciris.

The English names walking iris, apostle's iris and apostle plant have been used for many species, regardless of the generic placement (e.g. for Trimezia gracilis, syn. Neomarica gracilis). New plantlets form at the end of the flower spikes; after flowering, the spikes fall over and a new plant grows, so the plant "walks". Names including "apostle" refer to the incorrect belief that plants do not flower until 12 or more leaves are present.

Description

The rootstock is variously described as an elongated corm or a rhizome. Plants vary in height from about 7abbr=onNaNabbr=on in the case of T. pusilla to 1.6abbr=onNaNabbr=on in the case of T. spathata subsp. sincorana. Linear to lanceolate leaves grow from the base of the plant. Most species have flowers in some shade of yellow. The six tepals are arranged in two series. The outer tepals (sepals) are larger than the inner ones (petals); both may have brown-purple markings at the base. The stamens have free filaments (i.e. they not fused together or fused to the style). The style is divided into three branches, each of which usually has two lobes.[2]

Taxonomy

The genus Trimezia was first published with an appropriate description by William Herbert in 1844. Herbert attributed the name to Salisbury, whose use he described as "Latin: absque charactere" ('without character'). The genus name is derived from the Greek words tri, meaning "three", and meze, meaning "greater".

Trimezia is placed in the tribe Trimezieae of the subfamily Iridoideae. The number of genera into which the tribe is divided has varied considerably. Three genera were used before 2008: Trimezia, Neomarica and Pseudotrimezia. Some sources used all three; others combined Trimezia and Neomarica but retained Pseudotrimezia. A further genus, Pseudiris, was published in 2008. Molecular phylogenetic studies have shown that although the tribe is monophyletic, the genera as traditionally used, based on morphological characteristics, are not. Three of the four main clades found in these analyses combine species from more than one genus. One response to these findings, adopted by Plants of the World Online and the World Checklist of Selected Plant Families, is to combine genera; thus Neomarica, Pseudiris and Pseudotrimezia are all placed within Trimezia. An alternative approach, retaining the traditional genera but with changed circumscriptions, was put forward in 2018; an additional new genus, Deluciris, was also created within the tribe.

Examples of alternative divisions of Trimezieae
Ravenna (2003) Chukr & Giulietti (2008) Gil & al. (2009) Lovo & al. (2018) PoWO (May 2019)
Trimezia Trimezia Trimezia Trimezia Trimezia
Neomarica Neomarica Neomarica
Pseudotrimezia Pseudotrimezia Pseudotrimezia Pseudotrimezia
    Pseudiris Pseudiris
      Deluciris Deluciris

Distinction between genera

When Trimezia was distinguished from Neomarica prior to molecular phylogenetic studies, i.e. entirely on morphological grounds, some vegetative characters were considered diagnostic. Trimezia in this sense always grows from corms, Neomarica almost always from rhizomes. Trimezia has flowering stems (scapes) that are circular in cross-section, whereas Neomarica has flattened scapes. Lovo et al. (2018) consider these characteristics to be among those distinguishing their circumscription of Neomarica from the other genera into which they divide the tribe.

Species

, the World Checklist of Selected Plant Families accepted about 80 species of Trimezia.[3] However, this includes species that other sources place in different genera in the tribe Trimezieae. The placement in Lovo et al. (2018), where given in their paper, is shown in the second column.

WCSP (May 2019) Lovo et al. (2018)
Trimezia altivallis Ravenna – Brazil (Espírito Santo)Neomarica altivallis
Trimezia barretoi (R.C.Foster) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia barretoi
Trimezia bauensis Ravenna – Brazil (Santa Catarina)
Trimezia brachypus (Baker) Ravenna – Brazil (Bahia)Neomarica brachypus
Trimezia brevicaulis Ravenna – Brazil (Bahia, Minas Gerais)Trimezia brevicaulis
Trimezia brevistaminea (Chukr) Christenh. & Byng – Brazil (Minas Gerais: Serra do Cipó)Pseudotrimezia brevistaminea
Trimezia campanula Lovo & Mello-Silva – Brazil (Minas Gerais)Trimezia campanula
Trimezia candida (Hassl.) Ravenna – SE. & S. Brazil to NE. ArgentinaNeomarica candida
Trimezia capitellata Ravenna – Brazil (Minas Gerais)Trimezia capitellata
Trimezia castaneomaculata (A.Gil & M.C.E.Amaral) Christenh. & Byng – Brazil (Bahia, Espírito Santo)Neomarica castaneomaculata
Trimezia cathartica (Klatt) Niederl. – Brazil (Bahia, Minas Gerais, Goiás)Pseudotrimezia cathartica
Trimezia caulosa Ravenna – Brazil (Bahia)Trimezia caulosa
Trimezia chimantensis Steyerm. – S. Venezuela (Macizo del Chimantá)Trimezia chimantensis
Trimezia cipoana (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia sublateralis
Trimezia coerulea (G.Lodd.) Ravenna – SE. & S. Brazil to ParaguayNeomarica coerulea
Trimezia concava (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia concava
Trimezia concolor Christenh. & Byng – Brazil (Minas Gerais: Serra do Cipó)
Trimezia datensis (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)
Trimezia decora Ravenna – Brazil (São Paulo)Neomarica decora
Trimezia decumbens Ravenna – Brazil (São Paulo)Neomarica decumbens
Trimezia diamantinensis (Ravenna) Christenh. – Brazil (Minas Gerais)Pseudotrimezia diamantinensis
Trimezia eburnea (A.Gil & M.C.E.Amaral) Christenh. & Byng – Brazil (Bahia)Neomarica eburnea
Trimezia elegans (Ravenna) Christenh. – Brazil (Minas Gerais: Pico Itambé)Pseudotrimezia elegans
Trimezia exillima Ravenna – Brazil (Minas Gerais)Trimezia exillima
Trimezia fistulosa R.C.Foster – Brazil (Minas Gerais: Serra do Cipó)Pseudotrimezia fistulosa
Trimezia floscella (A.Gil & M.C.E.Amaral) Christenh. & Byng – Brazil (Bahia)Neomarica floscella
Trimezia fluminensis Ravenna – Brazil (Rio de Janeiro)
Trimezia fosteriana Steyerm. – Venezuela (Bolívar)Trimezia fosteriana
Trimezia fulva (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia fulva
Trimezia glauca (Seub. ex Klatt) Ravenna – SE. & S. BrazilNeomarica glauca
Trimezia gracilis (Herb.) Christenh. & Byng – WC. & SE. Brazil to ParaguayNeomarica gracilis
Trimezia guaricana Ravenna – Venezuela (Guárico)
Trimezia guianensis Ravenna – Guyana
Trimezia humilis (Klatt) Ravenna – Venezuela, SE. & S. BrazilNeomarica humilis
Trimezia imbricata (Hand.-Mazz.) Christenh. & Byng – SE. BrazilNeomarica imbricata
Trimezia involuta (A.Gil & M.C.E.Amaral) Christenh. & Byng – Brazil (Bahia, Espírito Santo)Neomarica involuta
Trimezia itacambirae (Ravenna) Christenh. & Byng – Brazil (Minas Gerais: Serra do Alagoas)
Trimezia itamarajuensis Ravenna – Brazil (Bahia: Itamaraju)
Trimezia itatiaica Ravenna – Brazil (Rio de Janeiro)Neomarica itatiaica
Trimezia jaguatirica Ravenna – Brazil (Minas Gerais)
Trimezia juncifolia (Klatt) Benth. & Hook.f. – C. & S. BrazilPseudotrimezia juncifolia
Trimezia laevis (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia pauli
Trimezia latifolia Ravenna – Brazil (Paraná)Neomarica latifolia
Trimezia liebmannii Govaerts. – Brazil (Rio de Janeiro to Paraná)
Trimezia longifolia (Link & Otto) Christenh. & Byng – SE. BrazilNeomarica longifolia
Trimezia lutea (Klatt) R.C.Foster – Colombia to W. Venezuela, BrazilTrimezia lutea
Trimezia martinicensis (Jacq.) Herb. – C. America to Colombia, Lesser Antilles to BoliviaTrimezia martinicensis
Trimezia marumbina Ravenna – Brazil (Paraná)
Trimezia mauroi (A.Gil & M.C.E.Amaral) Govaerts. – Brazil (Rio de Janeiro)Neomarica mauroi
Trimezia mogolensis Ravenna – Brazil (Minas Gerais)
Trimezia monticola (Klatt) Christenh. & Byng – Brazil (Minas Gerais: Pico do Itambé)
Trimezia nana (Lovo & Mello-Silva) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia nana
Trimezia northiana (Schneev.) Ravenna – Brazil (Espírito Santo to Paraná)Neomarica northiana
Trimezia organensis Ravenna – Brazil (Rio de Janeiro)incertae sedis
Trimezia paradoxa Ravenna – Brazil (Maranhão)incertae sedis
Trimezia pardina Ravenna – Brazil (Minas Gerais, Rio de Janeiro)Neomarica pardina
Trimezia plicatifolia Chukr – Brazil (Minas Gerais: Serra do Cabral)Pseudotrimezia plicatifolia
Trimezia portosecurensis Ravenna – Brazil (Bahia)Neomarica portosecurensis
Trimezia pumila (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia pumila
Trimezia pusilla Ravenna – Brazil (Goiás: Serra Dourada)Pseudotrimezia pusilla
Trimezia recurvata (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia recurvata
Trimezia rigida (Ravenna) Christenh. & Byng – Brazil (Rio de Janeiro to Paraná)
Trimezia riopretensis Ravenna – Brazil (Minas Gerais)
Trimezia rotundata Ravenna – Brazil (Paraná)Trimezia rotundata
Trimezia sabini (Lindl.) Ravenna – E. BrazilNeomarica sabini
Trimezia sancti-vicentei (A.Gil & M.C.E.Amaral) Govaerts. – Brazil (São Paulo)Neomarica sancti-vicentei
Trimezia sergipensis (A.Gil & M.C.E.Amaral) Christenh. & Byng – Brazil (Sergipe)Neomarica sergipensis
Trimezia setacea (Klatt) Christenh. & Byng – Brazil (Minas Gerais: Serra do Cipó)
Trimezia silvestris (Vell.) Ravenna – SE. BrazilNeomarica silvestris
Trimezia sobolifera Ravenna – Florida, Mexico (Veracruz, Oaxaca), VenezuelaTrimezia sobolifera
Trimezia sooretamensis Ravenna – Brazil (Espírito Santo)
Trimezia spathata (Klatt) Baker – Brazil to NE. ArgentinaTrimezia spathata
Trimezia speciosa (Chukr & A.Gil) Christenh. & Byng – Brazil (Bahia)Neomarica speciosa
Trimezia steyermarkii R.C.Foster – S. Mexico to NW. VenezuelaTrimezia steyermarkii
Trimezia striata (Lovo & Mello-Silva) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia striata
Trimezia suffusa Ravenna – Brazil (São Paulo)
Trimezia synandra (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia synandra
Trimezia tenuissima (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia tenuissima
Trimezia truncata Ravenna – Brazil (Minas Gerais)Pseudotrimezia truncata
Trimezia unca Ravenna – Brazil (Bahia)
Trimezia variegata (M.Martens & Galeotti) Ravenna – C. & S. Mexico to PanamaNeomarica variegata
Trimezia warmingii (Klatt) Christenh. & Byng – Brazil (Minas Gerais)
Trimezia xyridea (Ravenna) Christenh. & Byng – Brazil (Minas Gerais)Pseudotrimezia planifolia

Former species

Some former species which are now regarded as synonyms include:[3]

Distribution and habitat

The genus is native to the warmer parts of southern Mexico, Central America, South America, Florida, and parts of the West Indies. Trimezia species typically grow in damp grassland.

Notes and References

  1. http://apps.kew.org/wcsp/namedetail.do?name_id=325236 Kew World Checklist of Selected Plant Families
  2. , pp. 375–379
  3. Search for "Trimezia",