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The results suggest that the impact of mites on nectar availability of Heliconia is more important with regard to total volume of nectar produced irrespective of flower longevity. A high variation among individuals in nectar produced in the populations was also observed. Hummingbird flower mites strongly affect availability of nectar for hummingbirds.

BackgroundThis study aimed to investigate the local botanical knowledge of native food plants in three rural communities, located in the semiarid region of Paraíba State, Brazil, verifying possibilities of differences of knowledge among communities and between men and women.MethodsSemi-structured interviews about native plant knowledge and use were conducted with all householders in each community, totaling 117 informants. The species similarity among the communities of Pau D’Arco, Várzea Alegre, and Barroquinha was compared with Jaccard index, and the use value index (UVgeneral, UVcurrent, UVpotential) was used to determine the most important species. The Kruskal-Wallis test was used to compare the use values among communities and genders. The consensus factor among the informants was calculated according to the uses cited, and the Wilcoxon test was used to compare the use values between men and women.ResultsWe recorded 9 species belonging to 8 genera and 8 families in Várzea Alegre; 10 species, 9 genera, and 9 families in Barroquinha; and 7 species, 7 genera and 7 families in Pau D’Arco. Spondias tuberosa Arruda (Anacardiaceae) in Várzea Alegre, Spondias sp. (Anacardiaceae) in Barroquinha, and Ximenia americana L. (Olacaceae) in Pau D’Arco were the most prominent species. Preparation methods are slightly different in the three communities, and there is low similarity about species use among the communities. Regarding gender, the analysis of use value among the communities evidenced significant differences only for UVgeneral among women, specifically between Barroquinha and Pau D’Arco. For men and women within each community, there is a difference only for UVpotential in Barroquinha.ConclusionThis study showed that the residents of the three rural communities have limited knowledge of native food plants found in their communities, but they know where to find them, which parts they may use and how to consume them. The fact is that men know plants that are more distant from the residences and women know those that are next to them.

Plant resources are essential to the survival of the human species, and they play several important roles in maintaining the quality of life. The purpose of this study was to assess the traditional knowledge of medicinal plants in the Ipiranga quilombola community on the south shore of the state of Paraı ´ba, northeast of Brazil. Ethnobotanical data were collected using semi-structured interviews that were performed with the head of the family for all the domestic units in the community (total of 100 individuals). Data were qualitative and quantitative (Use-Value index and informant consensus factor) analyzed. A total of 69 species belonging to 38 families were mentioned by the respondents. Only two medicinal species (Stryphnodendron pulcherrimum (Willd.) Hochr and Handroanthus impetiginosus (Mart. ex DC.) Mattos) are found in the surrounded Atlantic Forest area. All the other medicinal species are cultivated in backyards. The species with the highest Use-Values were Alpinia zerumbet (Pers.) B.L. Burtt. & R.M. Sm. (colony). The medicinal species were indicated for the treatment of 66 diseases, which were classified into 14 categories of body systems. Respiratory system disorders (0.54), gastrointestinal system disorders (0.43), and a genitourinary system disorder (0.42) were the categories with the highest consensus values among the respondents. The research showed that despite having a health center close to the community, the Ipiranga community still uses medicinal plants to cure diseases, with most species being cultivated in backyards.

The Neotropical orchid genus Sarcoglottis comprises ~40 species, which emit strong floral scents, presumably involved in pollinator attraction. Information on basic aspects of its natural history is scant, with the few studies available so far pointing to nectar‐seeking orchid bees as pollinators. Here, we investigated the reproductive biology of Sarcoglottis acaulis, addressing the ecological meaning of its floral scent. In Atlantic Forest fragments of NE Brazil, we described the floral biology, determined the breeding system and recorded the pollinators of S. acaulis. Additionally, we chemically characterized its floral scent and assessed its role on pollinator attraction. Although self‐compatible, S. acaulis depends on pollinators to boost fruit set. Male orchid bees of Eulaema atleticana and E. niveofasciata were the only recorded pollinators. They foraged for nectar only, in spite of the strong scent emitted by S. acaulis flowers. The floral scent is composed of six compounds, of which geraniol and nerol elicited electroantennographic responses in Eulaema bees. A synthetic mixture of these compounds attracted Eulaema bees in field assays but did not trigger the stereotyped scent‐gathering behaviour. The floral scent of S. acaulis acts in signalling and nectar is the sole reward for pollinators. Despite the low pollinator frequency, S. acaulis shows a high fruit set (77%), particularly when compared to other orchids. Attributes such as pollinia that release small pollen loads, allowing a single pollinia‐carrying bee to pollinate several flowers, low amount of nectar, steady‐state flowering and traplining behaviour of pollinators, might act together to assure this outstanding fruit set.

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Melocactus violaceus is an endangered species due to habitat destruction and the overcollection of this species for ornamental use. The aim of this study was to test the effect of different temperatures on the germination of M. violaceus. Three treatments were conducted: a constant temperature of 25°C, a 20-35°C alternating temperature, both inside germination chamber, and an alternating temperature under room temperature (mean temperature ranged from 25-37°C). The fi nal seed germination rates at the alternating temperature treatments were not signifi cantly different (65% in the seed germinator and 62.5% at room condition). However, both treatments with alternating temperatures had signifi cantly higher germination rates compared to the treatment kept at the constant temperature (8%). Our study showed that alternating temperatures between 20 and 37°C provides satisfactory conditions to induce a high percentage of seed germination of M. violaceus, without the passage of seeds through the digestive tract of its natural disperser, the lizard Tropidurus torquatus. This condition contributes to effi ciently producing seedlings that can be reintroduced into conservation areas or used as ornamentals that may help reduce the overcollection of the remaining native populations.