Diferenciação dos feixes vasculares e dos elementos traqueais no rizoma de algumas Cyperaceae

Abstract

-(Differentiation of vascular bundles and tracheary elements in the rhizome of some Cyperaceae). Were analized the rhizomes of Bulbostylis paradoxa Ness, Cyperus giganteus Vahl, C. odoratus L., Fuirena umbellata Rottb. and Hypolytrum schraderianum Ness. The primary body results from activity of primary meristems and primary thickening meristem (PTM). Secondary growth occurs too, due to the activity of the secondary thickening meristem (STM). Collateral vascular bundles are formed from procambium and MEP in H. schraderianum, and amphivasal bundles in the other species. However, all of the vascular bundles having protophloem and protoxylem are originated from procambium. Phloem and xylem are formed from MES in a single vascular tissue. Vessel elements were present in the most of the stems in primary and secondary growth, exception to H. schraderianum that has only tracheids in the last one; this information supports the occurrence of secondary growth in Cyperaceae. The vessel elements show a great morphological variation; generally, vessel elements from the primary growth, are longer and tip of vessel elements are present. The vessel elements from secondary growth are shorter and show tip of vessel elements and branchings.Key words -Cyperaceae, rhizome, tracheid, vascular bundles, vessel element RESUMO -(Diferenciação dos feixes vasculares e dos elementos traqueais no rizoma de algumas Cyperaceae). Foram analisados os rizomas de Bulbostylis paradoxa Ness, Cyperus giganteus Vahl, C. odoratus L., Fuirena umbellata Rottb. e Hypolytrum schraderianum Ness. O corpo primário é resultante da atividade dos meristemas apicais e do meristema de espessamento primário (MEP). Também ocorre crescimento em espessura, que é decorrente da atividade do meristema de espessamento secundário (MES). O procâmbio e o MEP originam feixes colaterais em H. schraderianum e feixes anfivasais nas demais espécies. Entretanto, todos os feixes que têm protofloema e protoxilema são de origem procambial. O MES produz floema e xilema constituindo um tecido vascular único. Elementos de vaso foram encontrados na maioria dos caules em estrutura primária e secundária, com exceção de H. schraderianum que, na estrutura secundária, contém apenas traqueídes, informação que respalda a ocorrência de crescimento secundário nas Cyperaceae. Os elementos de vaso apresentam grande variação morfológica; em estrutura primária, geralmente são mais alongados, com apêndices. Os elementos de vaso do crescimento secundário são relativamente mais curtos, apresentam apêndices e ramificações.Palavras-chave -Cyperaceae, elemento de vaso, feixes vasculares, rizoma, traqueíde

Anatomy of vegetative organs, inflorescence axis and pedicel in the Neoregelia bahiana complex (Bromeliaceae): taxonomic and ecological importance

“…The presence of such suberized tissue in the stem has previously been reported for species of Acanthostachys, Aechmea, Ananas, Billbergia, Bromelia L. (Bromelioideae), Dyckia (Pitcairnioideae) and Tillandsia L. (Tillandsioideae) Scatena 2004a, Proença andSajo 2008a), indicating that the short aerial stem probably grows in thickness as well. This growth is probably promoted by the pericycle and/or endodermis (primary thickening meristem), as documented in other monocotyledons (Diggle andDeMason 1983, Menezes et al 2005), including Poales such as Cyperaceae (Rodrigues and Estelita 2009), Eriocaulaceae (Scatena and Menezes 1995, Oriani et al 2008, Oliveira and Oriani 2016 and Rapateaceae (Menezes et al 2005). However, ontogenetic studies are necessary to elucidate the stem structure in Bromeliaceae and its relationship to the different life forms found in the family.…”

Botanical studies, antimicrobial activity and cytotoxity of Eleutherine bulbosa (Mill.) Urb

“…1P). The anphyvasal type is seen in some monocot specimens as E. bulbosa, even about in family Iridaceae there had already been related that diferentiated bundles present anphyvasal arrangement (Rodrigues & Estelita, 2009).…”