Morfologia dos tricomas das pétalas de espécies de Pseudobombax Dugand (Malvaceae, Bombacoideae) e seu significado taxonômico

Abstract

RESUMO -(Morfologia dos tricomas das pétalas de espécies de Pseudobombax Dugand (Malvaceae, Bombacoideae) e seu signifi cado taxonômico). O gênero Pseudobombax Dugand apresenta cerca de 30 espécies, é restrito à região Neotropical e apresenta taxonomia complexa, com muitas de suas espécies mal circunscritas. Parte de seus problemas taxonômicos é conseqüência do fato de que suas espécies perdem as folhas na fl oração e, portanto, a maioria delas é representada apenas por fl ores nas coleções de herbário. Neste trabalho, investigou-se a morfologia dos tricomas presentes nas pétalas de oito espécies de Pseudobombax. O estudo utilizou microscopia óptica e eletrônica de varredura a partir de amostras obtidas de material de herbário e fl ores fi xadas em etanol a 70%. Em todas as espécies de Pseudobombax analisadas, foram encontrados dois tipos principais de tricomas: (a) tricomas 2-4-armados, sésseis, longos, fl exíveis e com paredes fi nas, situados na face adaxial de todas as espécies; (b) tricomas tufosos, sésseis, curtos, rígidos, com paredes espessas e lignifi cadas, situados na face abaxial. Os dados qualitativos e quantitativos obtidos mostraram-se de valor taxonômico para a resolução de problemas de identifi cação específi ca em Pseudobombax. Palavras-chave: Morfologia, tricomas, Pseudobombax, Malvaceae ABSTRACT -(Morphology of trichomes in petals of Pseudobombax Dugand (Malvaceae, Bombacoideae) species and its taxonomic signifi cance). Trichome morphology of the petals of Pseudobombax Dugand species was investigated. The eight species selected of Pseudobombax were analyzed using optical microscopy and scanning electron microscopy. The study detected the existence of variation, both qualitative and quantitative, in morphology of trichomes in petals of species analyzed. In Pseudobombax petals, two kinds of trichomes were found: (a) trichomes 2-4-armed, sessile, long, fl exible and with thin walls, situated on the adaxial surface; (b) tufted trichomes, sessile, short, rigid, with thick, lignifi ed walls, on the abaxial surface of the petals. The qualitative and quantitative data were of taxonomic value for the resolution of problems of specifi c identifi cation in the genus.

Malvaceae from Serra do Lenheiro, Minas Gerais, Brazil

“…This species can be distinguished from others of the genus Pseudobombax by its large petioles 12.5-25.5 cm in length, glabrescent leaflets, calyx externally glabrate, petals internally glabrate in the basal third and oblong fruit (Carvalho-Sobrinho 2006). Although only one specimen was collected in the study area, the characteristics of the flowers were enough to recognize the species.…”

“…The characterization of these structures follows that of Radford et al (1974). More specific concepts of some genera were obtained from Lay (1950), Krapovickas & Cristóbal (1965), Fryxell (1988Fryxell ( , 1999, Carvalho-Sobrinho (2006), Krapovickas (2006), Saunders (2007) and Gonçalez & Esteves (2017). Additional material was used in the description of some taxa when structures like flowers or fruits were absent.…”

“…1823. Iconography: Duarte et al (2007 Pseudobombax tomentosum is distributed from Brazil to Paraguay (Carvalho-Sobrinho 2006). In Brazil, the species occurs in all regions, except the South.…”

A new species of Eriotheca (Malvaceae, Bombacoideae) from coastal areas in northeastern Brazil

“…Ongoing studies on the systematics of Neotropical Bombacoideae (Carvalho-Sobrinho and Queiroz 2008Carvalho-Sobrinho et al 2009, 2012, 2013a, b, 2014a, b, 2015, 2016; Carvalho-Sobrinho and Dorr 2017) have revealed herbarium specimens of Eriotheca from the coastal Atlantic states of Alagoas and Bahia in northeastern Brazil that are noteworthy because their leaves and fruits are smaller than others in the genus. Careful study of these specimens has led to the recognition of a new species, which is described and illustrated here.…”

Ontogenia de los tricomas foliares de Tilia caroliniana subsp. floridana (Malvaceae)

“…Con base en esos sistemas de desarrollo, Rao (1990) aclara la posición taxonómica del género Muntingia L. (Muntingiaceae). Varios estudios sobre las características morfológicas de los tricomas, han revelado un papel relevante en la sistemática de plantas a nivel de género (Hardin, 1979;Rajput et al, 1985;Redonda-Martínez et al, 2012) y especie (Carvalho-Sobrinho et al, 2009;Celep et al, 2014;Martínez-Gordillo y Espinosa-Matías, 2005;Shaheen et al, 2009).…”