We present the first multi-locus chloroplast phylogeny of Arthrostylidiinae, a subtribe of neotropical woody bamboos. The morphological diversity of Arthrostylidiinae makes its taxonomy difficult and prior molecular analyses of bamboos have lacked breadth of sampling within the subtribe, leaving internal relationships uncertain. We sampled 51 taxa, chosen to span the range of taxonomic diversity and morphology, and analyzed a combined chloroplast DNA dataset with six chloroplast regions: ndhF, trnD-trnT, trnC-rpoB, rps16-trnQ, trnT-trnL, and rpl16. A consensus of maximum parsimony and Bayesian inference analyses reveals monophyly of the Arthrostylidiinae and four moderately supported lineages within it. Six previously recognized genera were monophyletic, three polyphyletic, and two monotypic; Rhipidocladum sect. Didymogonyx is here raised to generic status. When mapped onto our topology, many of the morphological characters show homoplasy.

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Two new species, Merostachys ramosa and M. ximenae, from the Brazilian Atlantic forest are here described and illustrated. The species are apparently endemic to Minas Gerais state, with M. ramosa being restricted to the Parque Estadual da Serra do Brigadeiro. The conservation status of each species is examined. A key to all taxa of Merostachys present in eastern Minas Gerais and comments about the species are provided.

Realizou-se o levantamento florístico na Estação Ecológica do Tripuí, Ouro Preto, MG (43º34'33" W e 20º23'45"S). O clima da região é do tipo mesotérmico, com inverno seco (Cwb sg. Köppen) e com temperaturas médias oscilando entre 14º e 19ºC. A Estação apresenta como principais tipos vegetacionais as florestas mesófilas estacionais, o cerrado, a vegetação aquática (brejos, lagoa artificial e córregos) e as formações sucessionais ('candeial'). Para o levantamento florístico utilizou-se o método de parcelas e coletas por trilhas e caminhos, sendo identificadas 101 famílias, 242 gêneros e 462 espécies. As famílias que apresentaram maior riqueza específica foram Asteraceae (10,82%), Melastomataceae (8,22%), Myrtaceae (7,14%) e Rubiaceae (4,76%).

-(Flowering and fruiting of Aulonemia aristulata: a gynomonoecious woody bamboo species from Atlantic Forest in Brazil). Aulonemia aristulata (Döll) McClure is a lignified bamboo species endemic to Brazil. This species occurs in southeastern forests and can reach high density at forest edges, dominating the understory of canopy-disturbed forest patches. The goal of this study was to describe the flowering period, floral biology, fruiting and seedling recruitment of A. aristulata in natural conditions in two areas located in a segment of the Atlantic Forest. Data on the morphology of the synflorescences and florets, timing and sequence of the anthesis events and floral visitors were recorded. Natural pollinators (open pollination or control) as well as spontaneous self-pollination were also checked. Pollen viability was estimated using the acetocarmine technique. Aulonemia aristulata is monocarpic (semelparous) with gregarious flowering. All culms in both studied areas blossomed and fruited between August and November 2007, dying subsequently between December 2007 and April 2008. Two types of synflorescences and flowers were observed: terminal with bisexual and protandric florets, with the anthesis lasting for 3-4 days; and axillary, with morphologically bisexual, but functionally female, florets and anthesis lasting for 3-4 days. The latter were also observed in the rhizome of plants whose aerial portion had been removed. The presence of axillary synflorescences with pistillate flowers is described here for the first time in Aulonemia species. Moreover, this is the first report of gynomonoecy in woody bamboo. Fruiting from bisexual florets under natural conditions (35%) was superior to that obtained from bagged synflorescences (11.5%). Fruiting from functional female florets was around 20%. Pollen viability was on the average of 90%. The results suggest that Aulonemia aristulata is anemophilous. The massive bamboo seedling recruitment observed after dieback with the ability to colonize open areas could promote the regeneration of Aulonemia aristulata.Key words -floral biology, gregarious flowering, gynomonoecy, protandry, tropical forest RESUMO -(Floração e frutificação de Aulonemia aristulata: uma espécie de bambu lignificado ginomonoica da Floresta Atlântica no Brasil). Aulonemia aristulata (Döll) McClure é uma espécie de bambu lignificado endêmico do Brasil. Esta espécie ocorre em florestas do sudeste e pode atingir altas densidades em bordas de floresta e dominar o sub-bosque de manchas de floresta que tiveram o dossel perturbado. O objetivo deste estudo foi descrever o período de florescimento, a biologia floral, a frutificação e o recrutamento de plântulas de A. aristulata, em condições naturais, em duas áreas localizadas em um segmento de Floresta Atlântica. Foram registrados dados sobre a morfologia das sinflorescências e das espiguetas, tempo e sequência de eventos de antese e visitantes florais. Foram também verificadas a polinização natural (polinização aberta e controle) e a autopolinização ...