Isys Mascarenhas Souza

Morphological analyses suggest a new taxonomic circumscription for Hymenaea courbaril L. (Leguminosae, Caesalpinioideae)

Abstract Hymenaea is a genus of the Resin-producing Clade of the tribe Detarieae (Leguminosae: Caesalpinioideae) with 14 species. Hymenaea courbaril is the most widespread species of the genus, ranging from southern Mexico to southeastern Brazil. As currently circumscribed, Hymenaea courbaril is a polytypic species with six varieties: var. altissima, var. courbaril, var. longifolia, var. stilbocarpa, var. subsessilis, and var. villosa. These varieties are distinguishable mostly by traits related to leaflet shape and indumentation, and calyx indumentation. We carried out morphometric analyses of 14 quantitative (continuous) leaf characters in order to assess the taxonomy of Hymenaea courbaril under the Unified Species Concept framework. Cluster analysis used the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Bray-Curtis dissimilarity matrices. Principal Component Analyses (PCA) were carried out based on the same morphometric matrix. Two sets of Analyses of Similarity and Non Parametric Multivariate Analysis of Variance were carried out to evaluate statistical support (1) for the major groups recovered using UPGMA and PCA, and (2) for the varieties. All analyses recovered three major groups coincident with (1) var. altissima, (2) var. longifolia, and (3) all other varieties. These results, together with geographical and habitat information, were taken as evidence of three separate metapopulation lineages recognized here as three distinct species. Nomenclatural adjustments, including reclassifying formerly misapplied types, are proposed.

Estratégias fenológicas de Senna cana (Nees & Mart.) H.S. Irwin & Barneby (Fabaceae: Caesalpinioideae) como mecanismo eficiente para atração de polinizadores

The present work evaluated the importance of the phenological strategies of Senna cana in attracting floral visitors and pollinators in an riparian forest along the Lencois River, in Chapada Diamantina, Bahia, Brazil. Vegetative and reproductive phenological observations (leaf fall, leaf flushing, flowering, and fruiting) were made on a monthly basis among a group of 10 individuals. The floral biology patterns observed included: anthesis, duration of the flowers, stigma receptivity, pollen viability, and the presence of osmophores and pigments that reflect UV light. Reproductive mechanisms were examined by testing manual and natural self-pollination as well as cross-pollination. Visitors and pollinators were identified, and the time, duration, and frequency of their visitation, as well as their behavior, were noted. Senna cana is an episodic evergreen species showing seasonal and highly synchronous reproductive events (intermediate flowering after a rainy period, and long fruiting during the dry period). These flowering characteristics, in addition to the syndrome of melittophily, are important strategies for attracting floral visitors (including Xylocopa frontalis and X. grisescens, which are potential pollinators). The self-incompatibility and maximization of fruit production through cross-pollination represent reproductive mechanisms favored by the phenological strategies and the pollination syndrome demonstrated by this species.

Synchronization of leafing and reproductive phenological events in Hymenaea L. species (Leguminosae, Caesalpinioideae): the role of photoperiod as the trigger

We examined the phenology of three species of Hymenaea L. through field observations in savanna, deciduous dry forest, and ombrophilous forest environments to assess the effects of different environmental conditions on the leafing and reproductive behaviors of the plant populations there. We also used herbarium data to examine flowering aggregation for the entire genus based on the fact that the majority of its species show conserved floral attributes. This study focused on the following questions: Do phenological activities exhibit seasonality? Are there environmental triggers related to phenological events? Are leafing and reproductive events temporally aggregated in the genus? Our results indicate that Hymenaea species had similar annual patterns of phenological events, even though they grew under distinct climatic regimes. Photoperiod appears to function as the “trigger” for leafing and reproductive events in the group. The temporal aggregation of leafing and flowering events and high synchrony in different sites under distinct climatic regimes point to conservative phenological responses to the same environmental signal. This assertion was principally supported by the seasonality and aggregation of phenological events (especially flowering) even for species exposed to distinct climatic regimes. Furthermore, one of the most widely distributed species of the genus (both geographically and ecologically), Hymenaea courbaril L., demonstrated similar phenological timing, reinforcing the role of photoperiod as the principal environmental cue in the leafing and reproductive strategies of the genus.

A new species of Telmatoscopus Eaton (Diptera, Psychodidae) from Brazil

A new Brazilian species of Telmatoscopus Eaton (Diptera, Psychodidae) is described and illustrated. A key to males of Neotropical species of Telmatoscopus is provided.