Flower biology and subspecies concepts in Micropholis guyanensis (Sapotaceae): evidence of ephemeral flowers in the family

Abstract

Micropholis guyanensis (A.DC.) Pierre is a tree from the rainforests of tropical South America and includes two recognised and one informal subspecies. The species has a wide geographic distribution from Central America, northern and western South America to Amazonia and Bolivia, and is morphologically variable. All subspecies occur in the Reserva Florestal Adolpho Ducke just outside Manaus, Amazonas State in Brazil, and it can be questioned how they can grow in sympatry and retain their identity. We have studied vegetative variation, flower morphology and, to some degree, reproductive barriers. The species is dioecious, has five-merous, cream to greenish flowers that produce pollen, nectar and scent to attract pollinators. The flowering period is between June and October, and the plants set fruits, one seed in each, between November and April. There was no overlap in flowering period in the study area between two of the presumed subspecies, but both have similar floral morphology and are pollinated by the same species of butterflies and bees. We are not able to find any clear distributional or morphological discontinuities between the subspecies and we, therefore, suggest that M. guyanensis should be considered a variable species without formally recognised subspecies. Flowers of M. guyanensis are highly ephemeral and persist only for 1 day (~27 h) before falling to the ground. We predict that this is typical for many species of Sapotaceae, which can explain why the corolla is missing from the majority of herbarium specimens that at first sight have flowers.

Species tree phylogeny and biogeography of the Neotropical genus Pradosia (Sapotaceae, Chrysophylloideae)

“…However, classification of Sapotaceae has been notoriously difficult and different systems have been proposed (Baehni, 1938(Baehni, , 1965Lam, 1939;Aubréville, 1964;Pennington, 1990Pennington, , 1991, leading to unnatural and practically inconvenient classifications, mainly due to high degrees of morphological homoplasy Swenson et al, 2008a,b). Furthermore, circumscriptions of genera and species are prone to large uncertainties (Terra-Araujo et al, 2012b;Gomes et al, 2013), while conservation assessments have suggested that many species of Neotropical Sapotaceae are extinct, threatened to extinction, or endangered (IUCN Red List, 2013). Pennington (1990) revised Sapotaceae for the Neotropics, but over the last decade numerous additional species have been described (Pennington, 2006;Alves, 2011, 2012a,b;Morales, 2012;Terra-Araujo, 2012a.…”

DNA barcoding in Atlantic Forest plants: what is the best marker for Sapotaceae species identification?

“…The phenomena of supra-annual flowering and vegetative intraspecific morphological variation mean that flower and fruit analysis is necessary for correct identification of many Sapotaceae species. However, obtaining specimens with intact floral structures is not always possible because of the ephemeral nature of flowers from some species ( Terra-Araujo et al , 2012 ). Therefore, additional methods, e.g.…”

Island life - classification, speciation and cryptic species ofPycnandra(Sapotaceae) in New Caledonia

“…In terms of reproductive biology, virtually nothing is known about Sapotaceae except for three species of Planchonella in New Caledonia (Méndez & Munzinger, ) and one species of Micropholis (Griseb.) Pierre in South America (Terra‐Araujo et al ., ). Taken together, these examples point toward a diversity of situations that could have led to the evolution of cryptic species in New Caledonia such as differences in substrate type and disjunctions between areas with the same type of substrate, all of which may have contributed to this process.…”