The Structure of Petioles in Pteris (Pteridaceae)

Abstract

-(Leaf anatomy of Pteridaceae species from Rio Doce State Park (PERD) -MG). This study was carried out with the objective of selecting leaf anatomical characters that can help the taxonomy of Pteridaceae species growing in the PERD. During a preliminary survey, carried out in PERD, 57 species of ferns within 27 genera from 15 families were collected. The most representative family was Pteridaceae, with 17 species distributed in four genera (Adiantum, Hemionitis, Pityrogramma and Pteris). The leaves of these species showed glabrous, hairy or scaled petioles with unistratified epidermis and cortex composed by parenchyma and sclerenchyma. One meristele, in Pteris and Hemionitis, and two or three meristeles in Adiantum and Pityrogramma represent the petiole vascular system. In the distal region, these meristeles are classified in Adiantum as "Onoclea" and "Asterochlaena" types, in Hemionitis as "Grammitis" type, in Pityrogramma as "Onoclea" type, and in Pteris as "Loxsoma" and "Pteris podophylla" types. Leaf blade showed an uniestratified epidermis with idioblasts (sclereides). Idioblasts were parallel, oblique or restricted to veins in Adiantum and Pityrogramma, and reinforcing the leaf margins in Pteris. Idioblasts were absent only in Hemionitis. In some species, leaf blades were hairy or scaled. Anomocytic stomata sometimes associated to diacytic type were observed in the leaf abaxial surface in Adiantum, Hemionitis and Pityrogramma. In Pteris, stomata polocytic occur associated to copolocytic type. The mesophyll was homogeneous with "armed" cells in most Adiantum species or with lobed cells tending to isodiametric in the other genera. Hairs or scales, stomata type, presence and idioblasts distribution in the epidermis, type and disposition of petiole vascular tissue were the most relevant anatomical characters for the Pteridaceae identification in the PERD. RESUMO -(Anatomia foliar das espécies de Pteridaceae do Parque Estadual do Rio Doce (PERD) -MG). O objetivo desse estudo foi selecionar caracteres que possam auxiliar na taxonomia das espécies de Pteridaceae ocorrentes no PERD. Durante levantamento preliminar realizado no PERD, foram coletadas 15 famílias, 27 gêneros e 57 espécies de Pteridophyta. A família que apresentou maior número de representantes foi Pteridaceae com 17 espécies, distribuídas em quatro gêneros (Adiantum, Hemionitis, Pityrogramma e Pteris). As folhas destas espécies apresentam pecíolo glabro, piloso ou escamoso cuja epiderme é uniestratificada, córtex constituído por esclerênquima e parênquima e o sistema vascular representado por um meristelo, em Pteris e Hemionitis, e dois ou três meristelos em Adiantum e Pityrogramma. Na região distal do pecíolo, esses meristelos são classificados como do tipo "Onoclea" e "Asterochlaena" em Adiantum, "Grammitis" em Hemionitis, "Onoclea" em Pityrogramma e "Loxsoma" e "Pteris podophylla" em Pteris. A lâmina foliar apresenta epiderme uniestratificada com idioblastos esclerenquimáticos paralelos, oblíquos ou restritos às nervuras, em Adiantum e Pi...

Overview of the morphology, anatomy, and ontogeny of Adiantum capillus‐veneris: An experimental system to study the development of ferns

“…The lycophytes have microphylls, whereas the euphyllophytes, including ferns and seed plants, have macrophylls; these two kinds of leaves evolved independently (Baum, 1998;Dolan, 2009;Schulz et al, 2010). The presence of two vascular bundles in the base of petioles but fuse upwards is also common in Pteridaceae and Onoclea (Lin & DeVol, 1978;Martínez & Vilte, 2012). The leaf gap differentiates the stelar organization of ferns into several types, protostele, solenostele, and dictyostele (Tryon & Tryon, 1982;Qiu et al, 1995;Schneider et al, 2009).…”

“…The dictyostele stem of A. capillus‐veneris is the most specialized type of siphonostele (Gifford & Foster, ). The number and arrangement of meristeles and the junction of petiole base with the stem are important diagnostic characters, especially in identifying different taxonomic groups (Ogura, ; Martínez & Vilte, ). Rhizoids of the bryophytes and fern gametophytes have a simple structure only with several cells, whereas roots of ferns and seed plants are complicated.…”

Morphological and anatomical adaptations to dry, shady environments in Adiantum reniforme var. sinense (Pteridaceae)

“…The petioles of A. reniforme var. sinense had a central endodermis and a peripheral sclerenchyma layer underneath the epidermis, which is similar to other ferns (Hernandez-Hernandez et al, 2012), including Anemia (Ribeiro, Santos & Moraes, 2007), Pteris (Bondada, Tu & Ma, 2006;Martínez & Vilte, 2012;Sridhar et al, 2011;Palacios-Rios et al, 2019), Davallia (Ummu-Hani et al, 2013), Blechnum (Noraini et al, 2014), Asplenium (Wetzel et al, 2017), Doryopteris triphylla (Neira et al, 2017) and Pleopeltis macrocarpa (De los Ángeles Lagoria et al, 2018). In Asplenium species, the petiole endodermis was surrounded a sclerenchyma layer (Wetzel et al, 2017), whereas in Doryopteris triphylla, the petiole epidermis had a thick cuticle at the surface (Neira et al, 2017).…”

Morphology and anatomy of three species of <i>Asplenium L.</i> at Obafemi Awolowo University Ile-Ife, Nigeria

“…Authors including Ogura (1972); Martinez and Vilte (2012) and Pitterman et al, (2015) have considered the taxonomic importance of fern vascular bundles. The presence of two distinct vascular bundles observed in the Asplenium species agree with a general feature of the family Aspleniaceae.…”