A COMPARATIVE ANATOMICAL STUDY OF THE STEMS OF CLIMBING PLANTS FROM THE FOREST REMNANTS OF MARINGA, BRAZIL

Resumo

Climbing plants differ from self-supporting plants, such as shrubs and trees, in a range of characteristics, most notable are the mechanical properties of the stem. Liana stems as Pereskia aculeata Mill. (Cactaceae), Pisonia aculeata L. (Nyctaginaceae), Arrabidaea mutabilis Bureau et K.Schum. (Bignoniaceae), Dalechampia stipulacea Müll.Arg. (Euphorbiaceae) and Dicella nucifera Chodat (Malpighiaceae) were collected in Brazilian forest remnants. The objective of this paper is: a) to analyze the comparative stem structure of these species; b) to answer the inquiry whether these species present cambial variants or not and to verify the modes of cambial activities, and c) to contribute with the anatomical identification of the liana species, characterizing mainly the cambial variant types. The stems were sectioned by freehand and in rotation microtome, and stained with safranin, astra blue and toluidine blue. Stem epidermis is uniseriate with tector trichomes. Cortex consists of collenchyma, parenchyma and starch sheath. Pereskia aculeata and Pisonia aculeata have medullary collateral bundles. Phellogen is subepidermic. The species present stems with cambial variants, except Dalechampia stipulacea. Pereskia aculeata, Pisonia aculeata and Dicella nucifera have included phloem in the secondary xylem. Arrabidaea mutabilis presents cambial variants in four regions of the secondary vascular cylinder.