da Rosa Sônia M, de Souza Luiz A, Moscheta Ismar S
Universidade Estadual de Maringá, Departamento de Biologia, Av. Colombo, 5790-(87020-900) Maringá, Paraná, Brasil.
Acta Cient Venez. 2002;53(4):245-50.
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.
刺叶毒鼠子是一种分布广泛的物种，在巴西南部的热带和亚热带森林中经常出现。本文对其花托果和果实的发育进行了形态学和解剖学研究。在巴西巴拉那州马林加的森林植物园采集了开花前和开花后的花朵以及不同发育阶段的果实。花托果起源于花被，其特征为背面有单列表皮、有腺毛、正面表皮无毛且叶肉为薄壁组织。由于在花被阶段仍存在的腹侧分生组织的作用，最后一种组织呈现出大量的细胞层。果皮由子房壁发育而来。胚珠倒生、具双珠被和厚珠心。成熟种子的种皮薄，仅在种脊区域细胞壁加厚，有核起源的外胚乳和胚乳，珠被不发育。花托果在该物种的传播过程中（动物传播）具有重要意义。本研究证实该果实为瘦果而非文献中所认定的颖果。
