The first Loranthaceae fossils from Africa

Abstract

An ongoing re-investigation of the early Miocene Saldanha Bay (South Africa) palynoflora, using combined light and scanning electron microscopy (single grain method), is revealing several pollen types new to the African fossil record. One of the elements identified is Loranthaceae pollen. These grains represent the first and only fossil record of Loranthaceae in Africa. The fossil pollen grains resemble those produced by the core Lorantheae and are comparable to recent Asian as well as some African taxa/lineages. Molecular and fossil signals indicate that Loranthaceae dispersed into Africa via Asia sometime during the Eocene. The present host range of African Loranthaceae and the composition of the palynoflora suggest that the fossil had a range of potential host taxa to parasitise during the early Miocene in the Saldanha Bay region.

Combined LM and SEM study of the middle Miocene (Sarmatian) palynoflora from the Lavanttal Basin, Austria: Part V. Magnoliophyta 3 – Myrtales to Ericales

“…Likely, Arceuthobium dispersed southwards into Africa already during the Eocene, similar migration routes have recently been proposed for other plant groups, e.g. the Loranthaceae (from Asia; Grímsson et al 2017aGrímsson et al , 2018b and the Picrodendraceae (from Europe; Grímsson et al 2019). The restricted present-day distribution of Arceuthobium in Africa is most likely the result of post-Miocene climate and vegetation changes.…”

Origin and divergence of Afro-Indian Picrodendraceae: linking pollen morphology, dispersal modes, fossil records, molecular dating and paleogeography

“…More cold tolerant plants were able to follow this route until the middle to late Miocene (Denk et al 2010(Denk et al , 2011Graham 2018aGraham , 2018b. Such a 'northern route' has recently been proposed for another predominantly southern hemispheric group, the Loranthaceae, believed to have conquered Africa from Asia during the Eocene (Grímsson et al , 2018c. During the Eocene, Europe was influenced by hot and humid climate (Zachos et al 2001;Mosbrugger et al 2005), comparable to that of present day tropics to subtropics.…”

Consuming and consumed: Biotic interactions of African mistletoes across different trophic levels

“…Island mistletoe taxa (from Madagascar and the western Indian Ocean islands) show higher overall host specificity compared to mainland ones (Figure S2). However, this trend may be confounded by the unresolved phylogenetic and phylogeographic relationships of the mistletoe genera discussed here, some of which (e.g., Helixanthera and Korthalsella) presumably include components with distinct dispersal histories and of independent, relatively recent South Asian origin (Grímsson et al, 2018;Liu et al, 2018;Molvray et al, 1999;Polhill & Wiens, 1998). Overall, our compiled records (Table S1) do not indicate a consistent preference trend for island versus mainland mistletoes, with significant overlap in their general host ranges at the genus level.…”

“…Following the last comprehensive assessment of host associations in African mistletoes by Polhill and Wiens (1998, 1999a, 1999b) and a number of regional studies (see Table S1 for the reference list), Grímsson et al (2018) have recently compiled the continent-wide published host species records for the African Loranthaceae. In contrast, the island mistletoe taxa (from the Madagascar and neighboring islands) have remained virtually unaddressed in terms of host associations since Balle (1964aBalle ( , 1964b and Philcox (1982), except for occasional studies dealing with individual mistletoe taxa (Albert et al, 2017).…”