Cactaceae has many vertebrate-pollinated species, and in the subtribe Cereinae, several genera are indicated as being pollinated by bats. In this subtribe, we observed phenotypic specialization in floral morphological attributes associated with chiropterophily, allowing high precision in the determination of this pollination system. However, in loco pollination records of bats have been confirmed only in a few species. In this context, using a morphological approach, we studied the floral biology of 14 columnar cacti of Cereeae-Cereinae with emphasis on species with chiropterophilous attributes and confirmed the role of bats specialized in nectar consumption as pollinators of these taxa. The studied taxa have similarities in their floral bauplan, observed by analysing the overlap in the floral morphospace. The length and opening of the floral tube are important characteristics for pollen deposition. Approximately 156 visits by bats of the subfamilies Glossophaginae and Lonchophyllinae were observed among the studied taxa. Chiropterophily is the prevalent pollination system among Cereinae, and hereby, we verified this system in five of its genera. There is, however, much variation between diurnal and nocturnal systems within this subtribe, and variation among genera and within species of a given genus may reflect the evolutive pathways, this being worthy of future studies.

Cereus jamacaru is a cactus distributed in Northeastern Brazil, with high symbolic value to this region. However, the interaction, behavior and the role of pollinators remains poorly understood. Here, we investigate the reproductive biology, addressing the ecological significance of floral attributes, including details about floral signaling. The study was carried at three areas of the Caatinga, in 2015, 2017 and 2021. We analyzed the floral morphometry, volume and concentration of the nectar, and characterized the colour and scent of flowers. Additionally, we described the pollinator behavior and performed controlled pollination experiments. The ‘Mandacaru’ is self-incompatible, has nocturnal anthesis and the nectar is accumulated as droplets in a long hypanthial tube. The flowers have a reflective pattern with a dark outer surface and a white inner surface. (E)-nerolidol is the major component (87.4%) of its floral perfume. We registered the sphingid moth Cocytius antaeus visiting the flowers. The floral attributes, attractants and rewards drives to a sphingophily, and the pollination treatments showed the dependence to fruit set by C. antaeus, the pollinator registered. In this case, if the apparent lack of pollinator diversity encompasses its entire range, the loss of the hawkmoth could severely impact the reproductive success of the cactus.

A total of twenty-one taxa of Cactaceae, including hybrids, are newly recognised or reevaluated for the area defined for the Cacti of Eastern Brazil, some being described for the first time. Other taxonomic changes are noted together with various range extensions and many of the plants concerned are illustrated.