The genera and species of Piperaceae show a considerable structural diversity of leaves and especially stems. This paper presents a comparative morphological and anatomical study of the leaves and stems of three common Brazilian species of this family (Peperomia dahlstedtii C.DC., Ottonia martiana Miq. and Piper diospyrifolium Kunth), the vegetative organs of which have previously been little studied. The collected plant material was fixed in FAA, cut freehand and stained in safranin and astra blue. P. dahlstedtii is an epiphyte and has a herbaceous stem with whorled leaves phyllotaxis and a polystelic structure, a multiseriate adaxial leaf epidermis and calcium oxalate monocrystals in parenchyma and collenchyma petiole cells. O. martiana and P. diospyrifolium showed strong similarities, both being terrestrial plants, with alternate phyllotaxis, stele with medullary bundles and dorsiventral leaves with an epidermis and subepidermic layer. In O. martiana the stomatal complex is staurocytic and presented silica crystal sand in parenchyma petiole and midrib cells. In P. diospyrifolium the stomatal complex is tetracytic and there are calcium oxalate raphide crystals in the parenchyma of the petiole and midrib cells. On the other hand, the three species show some structural likenesses in that all have hypostomatic and dorsiventral leaves, oily cells in petiole and mesophyll, secretory trichomes and an endodermis with Casparian strips.

-(Morphology, anatomy and ontogeny of the pericarp of Manihot caerulescens Pohl and M. tripartita Müll. Arg. (Euphorbiaceae)). Manihot caerulescens and M. tripartita are shrub species of cerrado, known as "mandioca-brava". Works on structure of pericarp of Euphorbiaceae are rare and many of the found morphologic descriptions present dubious interpretations, especially on the dehiscence. The present work aimed to describe the morphology, anatomy and ontogeny of pericarp of the two species of Manihot, comparing themselves and relating structural aspects of pericarp to the dehiscence. We verified that the pericarp follow four developmental periods, as typical of dry fruits. Two meristems are formed: a subadaxial, that produces the inner mesocarp; and another adaxial, that forms the endocarp, homogeneous and collenchymatous in M. caerulescens, and heterogeneous in M. tripartita, with outer gelatinous fiber-sclereids and an collenchymatous inner portion. We observed the formation of separation tissue, composed of loose parenchyma, in direction to the dorsal bundle of the three carpels and to the septa, which are more evident in M. tripartita. Finally, we verified variation in the sclerenchymatous stratum: in M. caerulescens, there is a layer of fiber-sclereids and one of stone cells, both of the mesocarp; in M. tripartita, these two mesocarpic layers occur, with bigger thickness, increased of the outer endocarp, also composed of fiber-sclereids. The fruits of both species are capsules which type depends on the development of separation tissue and of the dimension of sclerenchymatous stratum. Thus M. caerulescens presents indehiscent capsules, while M. tripartita forms septi-loculicidal capsules, since the dehiscence, even so passive, occurs in the dorsal regions and in the direction to septa.Key words -anatomy, development, Manihot, morphology, pericarp RESUMO -(Morfoanatomia e ontogênese do pericarpo de Manihot caerulescens Pohl e M. tripartita Müll. Arg. (Euphorbiaceae)).Manihot caerulescens e M. tripartita são espécies arbustivas de cerrado, conhecidas como mandiocabrava. Não são encontrados muitos trabalhos sobre estrutura do pericarpo de Euphorbiaceae e muitas das descrições morfológicas existentes apresentam interpretações dúbias, especialmente sobre a deiscência. O presente trabalho objetivou descrever a morfologia, anatomia e ontogênese do pericarpo das duas espécies de Manihot, comparando-as entre si e relacionando aspectos estruturais do pericarpo à deiscência. Verificou-se que o desenvolvimento do pericarpo enquadra-se em quatro estágios, típicos de frutos secos. Dois meristemas são formados: um subadaxial, que produz o mesocarpo interno; outro adaxial, que forma o endocarpo, homogêneo e colenquimatoso em M. caerulescens, e heterogêneo em M. tripartita, com fibroesclereídes gelatinosas externas e uma porção colenquimatosa interna. Observou-se a formação de tecido de separação, composto por parênquima laxo, em direção aos feixes dorsais dos três carpelos e aos septos, o qual é mais evidente em M. t...

RESUMO.As plântulas de Tabebuia avellanedae Lor. ex Griseb. (ipê-roxo) e T. chrysotricha (Mart. ex DC.) Standl. (ipê-amarelo), espécies arbóreas que ocorrem no Estado do Paraná, foram estudadas morfoanatomicamente. As plântulas foram obtidas de sementes coletadas no campus da Universidade Estadual de Maringá, Paraná, Brasil. As seções anatômicas foram feitas a mão livre e coradas com azul de astra e safranina. As plântulas são fanerocotiledonares e epigéias. A raiz é axial e pentarca/heptarca em T. avellanedae e tetrarca/hexarca em T. chrysotricha. A zona de transição ocorre no hipocótilo. O mesofilo cotiledonar é homogêneo em T. avellanedae e heterogêneo em T. chrysotricha. Os eofilos são folhas simples e dorsiventrais e os metafilos de tirodendros são compostos digitados e isobilaterais. Eofilos e metafilos são hipostomáticos, com complexos estomáticos anomocíticos e tricomas glandulares e tectores.Palavras-chave: plântula, morfologia, anatomia, Tabebuia. ABSTRACT. Seedlings morphology and anatomy of Tabebuia avellanedae Lor. ex Griseb and T. chrysotricha (Mart. ex Dc.) Standl. (Bignoniaceae). Seedlings ofTabebuia avellanedae Lor. ex Griseb. ("ipê-roxo") and T. chrysotricha (Mart. ex DC.) Standl. ("ipê-amarelo"), arboreal species that occurr in the state of Paraná, southern Brazil, are morphologically and anatomically studied. Seedlings were obtained from seeds collected at the Universidade Estadual de Maringá, state of Paraná. Anatomical sections were handmade and stained with astra blue and safranin. Seedlings are phanerocotylar and epigeal. The root is axial and pentarch-heptarch in T. avellanedae and tetrarch-hexarch in T. chrysotricha. The root-shoot transition region occurs in the hypocotyl. Mesophyll cotyledonous is homogeneous in T. avellanedae and heterogeneous in T. chrysotricha. Eophylls are simple and dorsiventral leaves and metaphylls are compound and isobilateral. Eophylls and metaphylls are hypostomatic with anomocytic stomatal complexes and glandular and non-glandular trichomes.

Morfologia e desenvolvimento da plântula de Acalypha gracilis (Spreng.) Müll. Arg, Euphorbia cotinifolia L. e Jatropha gossypiifolia L. (Euphorbiaceae) Morphology and development of seedlings of Acalypha gracilis (Spreng.) Müll. Arg, Euphorbia cotinifolia L. and Jatropha gossypiifolia L. (Euphorbiaceae)

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