Abstract This study aimed to determine the biometric characteristics of seeds of Tabebuia aurea and evaluate the effect of different periods of water immersion on the initial growth of seedlings. For this, the following dimensions were analyzed: length, width, and thickness of seeds with lateral wings and embryo. The moisture content, weight of a thousand seeds, and the number of seeds per kilogram were determined. The seeds were subjected to 11 treatments, as follow: control (no immersion in water; 0 hours) and periods of water immersion for 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 hours, with four replications of 25 seeds in each treatment. The aerial part and seedling root lengths were analyzed 30 days after sowing. The water content was 9.81% and the weight of a thousand seeds was 130.260 g, corresponding to about 7,677 seeds/kg. The seeds with lateral wings had mean length, width, and thickness of 5.252, 1.226, and 0.147 cm, respectively. For the embryo, these dimensions corresponded to 1.355, 0.805, and 0.103 cm. Regarding the aerial part and root length of T. aurea seedlings, immersion for 48 hours is recommended because this treatment had the best results.

Abstract The correlation between biological and ecological parameters is essential for the sustainable use of species. This study aimed to assess the relationship between phenological intensity and tannin production in Sideroxylon obtusifolium (Roem. & Schult.) T.D.Penn. in environments with different precipitation regimes. The tannin production and phenological characterization were assessed through the intensity and synchrony of leaves, flower buds, flowers, and fruits in specimens from two microregions of Paraíba, northeastern Brazil. The specimens in the municipality of Sumé were not synchronous and fruiting is the least synchronous phenophase, with an index of only 0.17. The specimens in São João do Cariri had synchronization of 0.77, 0.82, and 0.92 for flower bud, flowering, and fruiting phenophases, respectively. The correlation and factorial clustering showed that fruiting has a correlation of -0.75 with the production of tannins, suggesting that low intensity of annual fruiting is necessary for higher tannin production.

ABSTRACT Public squares are important spaces in the cities and stand out for providing improvements in the quality of urban life. Thus, this study aimed to carry out the floristic survey of public squares in the city of Areia, Paraíba state, Brazil, and analyze the similarity between their flora. The species classification was performed by consulting experts and through comparative morphology. The floristic similarity was calculated using the Jaccard index. Twenty-nine species distributed in 26 genera and 20 families were recorded. Stenotaphrum secundatum (Walter) Kuntze had the highest relative frequency (8.52%). Sixty-three percent of the species are exotic and 28% contain toxic substances. There was a significant similarity (1) only between Tenente Juvenal Espíndola and Simeão Patrício squares. The data evidence the need for better planning of floristic composition of the squares in the city of Areia, as well as for a tree planting manual.