When the absence of evidence is not the evidence of absence: Nasa (Loasaceae) rediscoveries from Peru and Ecuador, and the contribution of community science networks.

Documentation of plant taxa has long been subject to the temporal and spatial selectivity of professional research expeditions, especially in tropical regions. Therefore, rare and/or narrowly endemic species are sometimes known only from very few and very old herbarium specimens. However, these taxa are very important from a conservation perspective. The lack of observations of living plants and confirmation of the actual occurrence of taxa hinders the planning and implementation of effective conservation measures. Community science networks have recently made tremendous contributions to documenting biodiversity in many regions across the globe. The rediscovery of six species of Nasa (Loasaceae) from Peru and Ecuador primarily via the platform iNaturalist, is reported.

Hypopigmentation in mantled howler monkeys Alouatta palliata (gray 1849): First documented cases of whole-body leucism in South America.

The existence of hypopigmentation like leucism is the result of genetic anomalies that might be enhanced by external factors such as pollution. This anomaly may reduce survival rates. Leucism has been recorded in wildlife, but overall, it is considered very rare. There have been few records of mantled howler monkeys with leucism in Mexico and Costa Rica, but whole-body leucism in howler monkeys from South America was unknown. In this article, we report for the first-time documented cases of whole-body leucism in young individuals of mantled howler monkeys Alouatta palliata in an isolated remanent of tropical dry forest in southwestern Ecuador known as Cerro Blanco Protective Forest. In total, we found two juvenile individuals with leucism in October 2021. The report of howler monkeys with whole-body leucism may be caused by two processes: inbreeding because of isolated populations, environmental pressure caused by pollution, or the interaction of both. Our findings also reveal that hypopigmentation is becoming more frequent in howler monkey populations along its distributional range. Therefore, it is important to promote research in this field to disentangle the causes of hypopigmentation and to consider a regional management strategy for the species.

La existencia de afecciones que causan hipopigmentación, como el leucismo, son el resultado de anomalías genéticas que pueden verse potenciadas por factores externos como la contaminación. Estas anomalías puedes reducir las tasas de supervivencia. Se ha registrado leucismo en la vida silvestre, pero en general, se considera muy raro. En México y Costa Rica se ha reportado la existencia de casos aislados de monos aulladores de manto con leucismo, pero se desconocía el leucismo de cuerpo completo en monos aulladores para América del Sur. En este artículo, reportamos por primera vez casos documentados de leucismo en todo el cuerpo en individuos juveniles de monos aulladores de manto Alouatta palliata en un remanente aislado de bosque seco tropical en el suroeste de Ecuador conocido como Bosque Protector Cerro Blanco. En total, encontramos dos individuos juveniles con leucismo en octubre de 2021. Este reporte de monos aulladores con leucismo en todo el cuerpo puede ser causado por dos procesos: apareamiento dentro de individuos de la misma población causado por el aislamiento, la presión ambiental causada por la contaminación o la interacción de ambos. Nuestros hallazgos también revelan que la hipopigmentación es cada vez más frecuente en las poblaciones de monos aulladores a lo largo de su rango de distribución. Por lo tanto, es importante promover la investigación en este campo para determinar las causas de la hipopigmentación y considerar una estrategia de manejo regional para la especie. Palabras clave: aberraciones cromáticas, pérdida de conectividad, anomalías genéticas, endogamia, cambio de pigmentación en primates por contaminación, Bosque Seco del Pacífico Ecuatorial.

Rediscovery of Gasteranthusextinctus L.E.Skog & L.P.Kvist (Gesneriaceae) at multiple sites in western Ecuador.

We report the rediscovery of the Critically Endangered cloud forest herb Gasteranthusextinctus, not seen since 1985. In 2019 and 2021, G.extinctus was recorded at five sites in the western foothills of the Ecuadorian Andes, 4-25 km from the type locality at the celebrated Centinela ridge. We describe the species' distribution, abundance, habitat and conservation status and offer recommendations for further research and conservation efforts focused on G.extinctus and the small, disjunct forest remnants it occupies.

Re-establishment of the genus Pseudalbizzia (Leguminosae, Caesalpinioideae, mimosoid clade): the New World species formerly placed in Albizia.

Following recent mimosoid phylogenetic and phylogenomic studies demonstrating the non-monophyly of the genus Albizia, we present a new molecular phylogeny focused on the neotropical species in the genus, with much denser taxon sampling than previous studies. Our aims were to test the monophyly of the neotropical section Arthrosamanea, resolve species relationships, and gain insights into the evolution of fruit morphology. We perform a Bayesian phylogenetic analysis of sequences of nuclear internal and external transcribed spacer regions and trace the evolution of fruit dehiscence and lomentiform pods. Our results find further support for the non-monophyly of the genus Albizia, and confirm the previously proposed segregation of Hesperalbizia, Hydrochorea, Balizia and Pseudosamanea. All species that were sampled from section Arthrosamanea form a clade that is sister to a clade composed of Jupunba, Punjuba, Balizia and Hydrochorea. We find that lomentiform fruits are independently derived from indehiscent septate fruits in both Hydrochorea and section Arthrosamanea. Our results show that morphological adaptations to hydrochory, associated with shifts into seasonally flooded habitats, have occurred several times independently in different geographic areas and different lineages within the ingoid clade. This suggests that environmental conditions have likely played a key role in the evolution of fruit types in Albizia and related genera. We resurrect the name Pseudalbizzia to accommodate the species of section Arthrosamanea, except for two species that were not sampled here but have been shown in other studies to be more closely related to other ingoid genera and we restrict the name Albizia s.s. to the species from Africa, Madagascar, Asia, Australia, and the Pacific. Twenty-one new nomenclatural combinations in Pseudalbizzia are proposed, including 16 species and 5 infraspecific varietal names. In addition to the type species Pseudalbizziaberteroana, the genus has 17 species distributed across tropical regions of the Americas, including the Caribbean. Finally, a new infrageneric classification into five sections is proposed and a distribution map of the species of Pseudalbizzia is presented.