Catasetum roseoalbum Lindley 1840
Creators: name: Barberena, Felipe Fajardo V. A.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Asparagales
Orchidaceae
Catasetum
Catasetum roseoalbum

description: Catasetum roseoalbum (Hooker) Lindley (1840: 65). Fig. 1 A–B.
= Monochanthus roseo-albus Hooker (1840: t. 3796). = Catasetum discolor var. roseoalbum (Hooker) Mansfeld (1932: 264).
Type:— BRAZIL. Pará, Bulley s.n., sent by Mr. Campbell to Mr. Murray at the Glasgow Botanical Garden (K 588820, digital image!).
= Catasetum ciliatum Barbosa Rodrigues (1877: 130).
Type:— BRAZIL. Pará: Belém, B.Rodrigues s.n.; lectotype (designated by Romero & Jenny 1993):—Barbosa Rodrigues’s Iconographie des Orchidées du Brésil, ined., t. 282, copy K [reproduction printed in “ Iconographie des Orchidées du Brésil ”, Sprunger et al. (1996, Vol. 1: 341), Vol. 5: t. 216 A, based on Barbosa Rodrigues’ original watercolor bound in the library of the Jardim Botânico do Rio de Janeiro].
Catasetum roseoalbum occurs from Colombia to the Northern region of Brazil (Govaerts et al. 2021), it presents variable floral morphology and is poorly understood taxonomically. Hooker (1840) described Monochanthus roseo-albus based on specimens collected in the state of Pará, and distinguished by the downy lip with reddish vertical stripes inside, reddish and long-fimbriate lip margin, and reddish and remarkably pointed lip apex. Upon transferring M. roseo-albus to the genus Catasetum Richard ex Kunth (1822: 330), Lindley (1840) noticed that the flowers were described as white by Hooker (1840) but illustrated as greenish-yellow. This color variation can be naturally observed in different specimens of C. roseoalbum (Fig. 1).
Based mainly on data regarding the habitat and pollinators, Romero & Carnevali (1989) considered C. roseoalbum a natural hybrid between Catasetum discolor (Lindley) Lindley (1835: t. 1735) and Catasetum longifolium Lindley (1839: 94) and changed its nomenclatural status to that of nothotaxon. Their proposal has been followed by several subsequent authors (e.g., Pessoa et al. 2015; Petini-Benelli 2020; Govaerts et al. 2021). However, the taxon has also been considered a synonym of C. discolor (Sprunger et al. 1996), a variety of C. discolor (Holst 1999) or an autonomous species (Bastos & van den Berg 2012). Catasetum roseoalbum is morphologically close to C. discolor, but has been distinguished by having the labellum ≤ 1.5 cm long, with margin laterally long fimbriate (vs. labellum> 1.5 cm long, with margin laterally short fimbriate to serrate) (Pessoa et al. 2015). Here it is treated as a distinct species.
Barbosa Rodrigues (1877: 130) described Catasetum ciliatum on the basis of specimens from Pará as well. The taxon featured yellowish sepals and petals, white and pubescent lip with brown transverse stripes internally, and long-fimbriate lateral lip margins. Catasetum ciliatum has previously been treated as a synonym of Catasetum discolor var. roseoalbum (Hooker) Mansfeld (1932: 264) and as a synonym for C. × roseoalbum by Romero & Jenny (1993). Nevertheless, it has also been treated as an autonomous species (e.g., Afonso et al. 2016), as a variety of C. × roseoalbum (Holst 1999) or as synonym of C. discolor (Govaerts et al. 2021). The description and Barbosa Rodrigues’ original illustration are consistent with the morphological circumscription of C. roseoalbum. Thus, C. ciliatum is here reaffirmed as a synonym of C. roseoalbum. This enables the proper naming of specimens deposited in herbaria and prevents that the number of Catasetum species be overestimated in future floristic or ecological studies, especially those carried out in Amazonian habitats.
Additional selected material:— BRAZIL. [Pará]: Belém, April 1908, J. Huber 2883 (MG 9327!). Marapanim, Vila de Marudá, Praia do Crispim, 16 June 1991, M. N. Bastos et al. 1046 (MG 145317!). Maracanã, praia da Marieta, 7 September 1994, M. N. Bastos et al. 1789 (MG 149317!). São Miguel do Guamá, Parque Sapucaia, 15 September 2018, J. R. V. Pacheco 39 (HCP 363!).
I thank the two anonymous reviewers for their suggestions and constructive comments, the curators of the herbaria cited in the text for allowing access to its collections, Josélia Pacheco and Marcelo Lima for granting permission to use photographs of Catasetum, and Erik Wild for reviewing English.
description: Published as part of Barberena, Felipe Fajardo V. A., 2021, Taxonomic notes on Catasetum roseoalbum (Orchidaceae: Epidendroideae): reaffirming Catasetum ciliatum as a synonym, pp. 171-173 in Phytotaxa 529 (1) on pages 171-172, DOI: 10.11646/phytotaxa.529.1.13, http://zenodo.org/record/5814236