Gochnatia polymorpha (Less.) Cabrera is a widespread Asteraceae species found in different physiognomies of cerrado (Neotropical savanna) and in forest formations of southeast Brazil. This study describes some leaf anatomy characteristics of this species and quantitatively evaluates them in relation to different environments, as well as under different light conditions. We found quantitative differences in all anatomical parameters analyzed. The results demonstrate that high leaf anatomy plasticity is an adaptive advantage that allows this species to occur in diverse cerrado conditions.

Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i) recently collected seeds and seeds after six months storage, ii) under constant and alternating temperatures, and iii) in the presence and absence of light. Germinability, mean germination time (MGT) and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.

Scleromorphic leaf structures are associated with plants growing under drought-prone conditions, high irradiances, and nutrient-poor soils. Sclerophylly can also be a valuable deterrent against herbivores. However, comprehensive studies of leaf anatomical traits encompassing different growth forms are lacking. The savannas of central Brazil (Cerrado) are characterized by high species diversity and a variety of growth forms. We performed a field study to characterize leaf anatomical traits and leaf mass per area (LMA) in 57 co-occurring Cerrado species of distinct plant families (located at different positions in the angiosperm phylogeny) and categorized according to the following growth forms: trees, palms, shrubs, subshrubs, vines, grasses and herbs. Plant growth form and leaf structure were interrelated. Four groups with distinct leaf anatomical syndromes were identified by NMDS analysis: grasses, palms, herbaceous (herbs, vines, and most subshrubs), and woody (trees and shrubs) plants. Trees and shrubs had scleromorphic dorsiventral leaves, with high tissue thickness and LMA. Herbaceous plants had thin, mesomorphic leaves. While most herbaceous plants had dorsiventral type of mesophyll, grasses and palms had homogenous mesophyll with sclerenchymatous bundle sheath extensions. Palms differed from grasses by having thicker leaves and sclerenchymatous hypodermis. In conclusion, Neotropical savannas cannot be exclusively described as scleromorphic vegetation.

Gochnatia polymorpha (Less.) Cabrera is a widespread tree species found in different physiognomies of neotropical savanna (cerrado) formations of south-eastern Brazil. The present study describes some leaf anatomical characteristics of this species as a function of the time of leaf flush, during dry or wet seasons. This species presents anatomical plasticity in the cuticle, palisade parenchyma and abaxial epidermis as well as in stomatal size and stomatal and trichome density, which are leaf structures linked with water-status control. Leaf structure changed to suit the particular environmental conditions during dry and wet seasons. The production of different wet- and dry-season leaf types in G. polymorpha could be a response to drought and an adaptation to environmental constraints in the cerrado.