[Reproductive structures of Piper amalago var. medium Linnaeus (Piperaceae)]. / Estruturas de reprodução de Piper amalago var. medium Linnaeus (Piperaceae).

Flowers, fruits, seeds and subterranean organ of Piper amalago var. medium Linnaeus were analyzed structurally. Flowers are hermaphrodite lacking perianth, with two stamens and a tricarpelate gynoecea. Tetrasporangiate anthers shows epidermis, endothecium, one or two middle layers and secretory tapetum. Ovary has a simple structure, with ventral meristem. There is one orthotropous, bitegmic and crassinucellate ovule. Fruits are drupes. Seeds are endotegmic with copious perisperm. Putamen is composed of a sclerified inner mesocarp and endocarp. Individuals of the species can be interlinked by radicular subterranean organ, that can spread vegetatively.

[Morphology, anatomy and floral biology of Cabralea canjerana (Vell.) Mart. (Meliaceae)]. / Morfo-anatomia e aspectos da biologia floral de Cabralea canjerana (Vell.) Mart. (Meliaceae).

Cabralea canjerana (Vell.) Mart. is a tree that occurs frequently in secondary forests of Maringá, Paraná, Brazil and presents a valuable wood. Its flowering time occurs from August to October and the anthesis occurs during the night. Its flowers are visited by Lepidoptera-Noctuidae. The flowers are unisexual and solitary or arranged in panicles. The perianth presents a papillose epidermis with striate cuticle and a parenchymatic mesophyll. Ten stamens constitute the androecium and are arranged in a staminal tube with anthers. The anthers present epidermis, endothecium, two median layers and secretory tapetum with binucleate cells. The semi-inferior ovary presents anatropous, bitegmic and crassinucleate ovules. The nectaries are located in the base of the ovary and staminal tube and they present papillose epidermis with stomata and secretory parenchyma with a conspicuous phloematic tissue.

[Morphology and anatomy od the development of the anthocarp and fruit of Pisonia aculeata L. (Nyctaginaceae)]. / Morfo-anatomia do desenvolvimento do antocarpo e do fruto de Pisonia aculeata L. (Nyctaginaceae).

Pisonia aculeata L. is a widespread species that occurs frequently in tropical and subtropical forests in the South of Brazil. This paper presents a morphological and anatomical study of the development of its anthocarps and the fruits. Flowers in pre and post anthesis and fruits in different stages of development were collected in the Horto Florestal of Maringá, Paraná State, Brazil. The anthocarp originates in the perigone and it can be characterized by the presence of an uniseriate epidermis on the abaxial surface, presence of glandular emergences, a glabrous epidermis on the adaxial surface and a parenchymatous mesophyll. This last tissue presents a great number of cellular strata due to the action of a ventral meristema installed still in the perigone phase. The pericarp develops from the wall of the ovary. The ovule is anatropous, bitegmic and crassinucellate. The mature seed presents a thin testa with thickened cell walls just in the rafe region, perisperm and endosperm with nuclear origin, without development of tegmen. The anthocarp has great importance in the process of dispersion of this species (epizoochory). This study confirms that the fruit is an achene and not a caryopsis as affirmed in the literature.