Resprouting is a functional trait in species which occur in fi re-prone ecosystems. These plants can resprout from aerial buds and by recruiting belowground bud bank using carbohydrates allocated in roots as resource. In this study, we present morpho-anatomical features and chemical composition related to the resprouting potential of two species of Eugenia L. in an area of the Cerrado (Brazilian savanna) under regeneration, after the clear-cutting of Pinus sp. with the later burning of pine needles layer. We used standard histological techniques for belowground organs analysis and aerial buds protection degree. Belowground buds in layer from soil surface down to 10 depth were counted and the chemical analyses were performed on roots. In all aerial buds, there were relevant protection traits. The belowground organ is a sobole and the number of buds in its upper portion varied from 24 to 517 between individuals of both species. Phenolic compounds, fl avonoids, starch and other carbohydrates were detected in roots. The protection of aerial buds, the large number of belowground buds and the storing and protective compounds may have favored the resprouting of the species in the area.

This study was carried out in a Cerrado (the largest savanna in the Neotropics) area where pine plantations, introduced in the 1970s, were removed by clear cutting of the trees and burning of the remaining material. After the removal and burning, some native shrub species resprouted. Since resprouting is dependent on buds that can be in the belowground bud-bearing (BBB) organs containing reserves, we selected three resprouting Myrtaceae species for analysis of morphology and anatomy of their BBB organs, to determine which compounds could be accumulated and to investigate the bud protection features. Standard histological techniques were used to analyse the BBB organs. The belowground bud bank at a depth of 10cm was determined. Nonstructural carbohydrates, total phenolics, and flavonoids were quantified on the roots. The large size of BBB organs suggest that these species were present before plantation establishment and survived plantation management treatments. All species produced a large number of axillary buds. All BBB organs exhibited significant lignification and stored starch and phenolic compounds in the parenchyma cells. The protective features and the storage of reserves associated with the bud-bank allowed the survival and subsequent resprouting of these species, contributing to the regeneration of this disturbed area.

Croton L. (Euphorbiaceae) is the second largest genus of the Euphorbiaceae s.l. family, which is composed of about 1,200 taxa. Several species are widely used medicinally in various parts of the world to treat cancer, digestive problems, skin diseases, malaria, ulcers, and obesity. The leaves and stems are sold as dehydrated fragments, or in powder form, and used in the preparation of teas and various types of formulations. The aim of this study was to accurately characterize the leaf anatomy of Croton bonplandianus Baill. and Croton gracilipes Baill. and to perform histochemical analysis of laticifers to provide subsidies for botanical certification. To accomplish this, leaf blade and petiole samples were fixed and prepared following standard techniques for scanning electron and light microscopy. Histochemical tests were carried out on sections to detect the compounds present in the secretions. Results showed neutral and acidic lipids, as well as phenolic compounds, in the latex. In addition, leaf anatomical structures of these two species were studied for specific identification of morphological characters and for quality assessment of these medicinal plants.

Seasonally-dry environments of the Neotropics, such as the South American Chaco, exert selective pressures on vegetation through a pronounced water defi cit. We describe the underground system and leaf anatomy of three species of Asteraceae from the Brazilian portion of the Chaco (Pterocaulon purpurascens Malme, Wedelia trichostephia DC., and Pectis gardneri Baker), aiming to describe their structural and adaptive features using standard plant anatomy techniques. Pterocaulon purpurascens and W. trichostephia exhibited slightly thickened xylopodia, with gemmiferous character and self-grafted stem shoots; Pectis gardneri displayed a slightly-thickened tuberous root with storage substances. Longitudinal sequences of cells with highly thickened walls forming globular protrusions were found throughout the extension of the periderm of Pectis gardneri, while senescent trichomes were found in the periderm of W. trichostephia. Schyzogenous aerenchyma was found in P. purpurascens. Aquifer cells, composing vascular rays of secondary phloem and xylem, are reported for this species. Leaves of the three species are perennial and amphistomatic, with aquifer cells in a variety of tissues. Pectis gardneri exhibits a "Kranz-type" anatomy with lignifi ed bristles with stomata. Th e features described for the species play important role in water uptake and/or storage, which prevent excessive water loss during environmental or physiological stress periods.