Development features of pericarp of Couroupita guianensis Aubl. (Lecythidaceae)

Abstract

At present, there is a paucity of works dedicated to carpological investigations of Couroupita guianensis Aubl. In order to identify structural features, particularly those related to fruit histogenesis and determination of its histogenetic type, we examined the anatomical and morphological characteristics of the fruit of C. guianensis at different stages of development. The observed structure of the pericarp allows for the identification of a specialized morphogenetic type of amphicarp, which has not been previously reported in other representatives of Magnoliophyta. The sclerenchymatous zones are localized in the outer and middle zones of the mesocarp. The morphological and anatomical features of the fruit indicate a discrepancy between the structure of the pericarp and the contemporary method of C. guianensis dissemination. It is hypothesized that the fruit is endozoochorous, although among the present-day fauna of South America, there are no animals capable of breaking the integrity of the powerful bony structure of the fruit, which is represented by the internal sclerenchymatous zone. Apparently, C. guianensis lost its potential disseminators after the late Quaternary extinction of megafauna. As hypothetical disseminators, some representatives of the families Megatheriidae, Nothrotheriidae, Gomphotheriidae, Mammutidae, and Toxodontidae could be suggested. Based on our investigations, we can conclude that the fruit of C. guianensis currently illustrates an evolutionary anachronism of dissemination.