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Tillandsioideae are composed of nine genera, most of these with unclear delimitation. The morphoanatomy of ovules and ovaries of 83 species from seven different genera was studied under light or scanning electron microscopy to contribute to the understanding of the relationships in the group. The nucellar epidermis and the parietal tissue showed a regular pattern for all Tillandsioideae. The presence of chalazal appendages, however, and their shape and size varied between the genera analysed. Most species had a single acuminate chalazal appendage. Catopsis was the only genus with multiple appendages. Guzmania and Racinaea lacked this structure. The integuments also presented a variable length and thickness among the different genera. The four to six layers of the outer integument were unique in Catopsis and the three cell layers condition in the inner integument of Tillandsia should be a retained feature as it was also observed in Catopsis. Many characteristics in ovule morphology presented here have great systematic value for distinguishing genera of the Tillandsioideae. In addition, these features can also help in the understanding of ovule evolution in Bromeliaceae as a whole. [ABSTRACT FROM AUTHOR]

In Bromelioideae, the so-called nidularioid complex contains closely related genera, the circumscription of which has been problematic. The goal of this study was to describe the ovary and ovule anatomy of six species of the nidularioid complex belonging to Canistropsis, Canistrum, Edmundoa, Neoregelia, Nidularium and Wittrockia and to use these characters in a parsimony analysis of relationships. In all analysed species, schizogenous-type aerenchyma is present in the ovarian mesophyll. Edmundoa lindenii has trichomes on the ovary surface, and this character appears to be an autapomorphy for the species. Canistrum aurantiacum exhibited some autapomorphies, such as four cell layers in the outer integument, non-elongated cells in the nucellar epidermis and three or four layers of cells in the parietal tissue. In the remaining species of the complex, the presence of transversally orientated ovules and anticlinally elongated cells in the outer integument in the micropylar region appear to be synapomorphies. Canistrum aurantiacum shares few characters with the other species; these results and the latest phylogenetic analysis show that Canistrum spp. do not belong to the current nidularioid clade. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177, 66-77. [ABSTRACT FROM AUTHOR]

Cyperaceae, the third largest family of monocotyledons, show unusual asexual reproductive strategies, such as pseudovivipary involving the formation of new individuals from somatic tissues of floral structures. In Eleocharis pseudovivipary is an important reproductive process in series Tenuissimae, which results in a structure called a proliferous spikelet. With the aim of describing the ontogenetic process of the pseudovivipary in E. viridans, proliferous spikelets at different developmental stages were analysed by light microscopy and scanning electron microscopy. The proliferous spikelet develops from a meristem located in the axil of the basal glume, homologous to bracts of other groups of Cyperaceae, in the culm of the parental plant. Each proliferous spikelet is formed by sympodial units, which consist of an addorsed prophyll, an outer and inner sheath and a culm, which develops a primordium of floriferous spikelet at the terminal region, which can be aborted, and may develop a proliferous spikelet lateral in the axil of the basal glume. The second internode of each sympodial unit contains a root primordium and an intercalary meristem at the culm base. Our results indicate that pseudovivipary can coexist with sexual reproduction as an alternative reproductive strategy, allowing the rapid spread of populations. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176, 524-539. [ABSTRACT FROM AUTHOR]