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1.
PLoS One ; 18(4): e0284665, 2023.
Article in English | MEDLINE | ID: mdl-37079631

ABSTRACT

Incorrect labelling of plants in the horticultural trade and misidentification is widespread. For the inspection services of the EU member states, correct identification of G. tinctoria has become important since the species was added to the List of Union concern in accordance with EU regulation 1143/2014 in August 2017. In the horticultural trade Gunnera plants are generally of modest dimensions and rarely flowering, so that the major distinguishing morphological characters for the identification of the two large species, G. tinctoria and G. manicata, are missing. As G. tinctoria is included in the EU regulation, its trade is prohibited, although the closely related species, G. manicata is not included on the list. Given that it is often difficult to distinguish between these two large herbaceous species using morphological attributes we used standard chloroplast DNA barcode markers, supplemented at a later stage by ITS markers. Plant material of putative G. tinctoria or G. manicata was obtained from the native and introduced range, both from "wild" sources, botanical gardens, and the horticultural trade. In western Europe plants circulating in the horticultural trade turned out to be predominantly G. tinctoria, with only one plant in cultivation identified as true G. manicata and the G. manicata found in botanical gardens was a hybrid recently described as G. x cryptica.


Subject(s)
Plants , Seeds , Europe , Dietary Supplements
2.
Grana ; 58(2): 81-98, 2019.
Article in English | MEDLINE | ID: mdl-30828285

ABSTRACT

The palm family, Arecaceae, is notoriously depauperate in Africa today, and its evolutionary, paleobiogeographic, and extinction history there are not well documented by fossils. In this article we report the pollen of two new extinct species of the small genus, Sclerosperma (Arecoideae), from a late Oligocene (27-28 Ma) stratum exposed along the Guang River in Chilga Wereda of north-western Ethiopia. The pollen are triporate, and the two taxa can be distinguished from each other and from modern species using a combination of light and scanning electron microscopy, which reveals variations in the finer details of their reticulate to perforate exine sculpture. We also report a palm leaf fragment from a stratum higher in the same section that is in the Arecoideae subfamily, and most likely belongs to Sclerosperma. The implications of these discoveries for the evolutionary history of this clade of African arecoid palms is that their diversification was well underway by the middle to late Oligocene, and they were much more widespread in Africa at that time than they are now, limited to West and Central Africa. Sclerosperma exhibits ecological conservatism, as today it occurs primarily in swamps and flooded forests, and the sedimentology of the Guang River deposits at Chilga indicate a heterogeneous landscape with a high water table. The matrix containing the fossil pollen is lignite, which itself indicates standing water, and a variety of plant macrofossils from higher in the section have been interpreted as representing moist tropical forest or seasonally inundated forest communities.

3.
Grana ; 58(2): 99-113, 2019.
Article in English | MEDLINE | ID: mdl-30828286

ABSTRACT

Three currently accepted Sclerosperma species appear to produce four different pollen morphologies. Sclerosperma mannii and S. walkeri pollen share the same distinct reticulate sculpture, but S. profizianum produces three different pollen types (microreticulate, fossulate, and perforate). The pollen morphology suggests that S. mannii and S. walkeri are sister taxa of the same intrageneric lineage. The pollen diversity observed in S. profizianum suggests (a) this taxon is unique regarding its pollen diversity despite being a non-heterostylous plant or (b) that circumscription of S. profizianum as a species may well be in the need of redefinition.

4.
Proc Natl Acad Sci U S A ; 108(30): 12343-7, 2011 Jul 26.
Article in English | MEDLINE | ID: mdl-21746913

ABSTRACT

The marked biogeographic difference between western (Malay Peninsula and Sumatra) and eastern (Borneo) Sundaland is surprising given the long time that these areas have formed a single landmass. A dispersal barrier in the form of a dry savanna corridor during glacial maxima has been proposed to explain this disparity. However, the short duration of these dry savanna conditions make it an unlikely sole cause for the biogeographic pattern. An additional explanation might be related to the coarse sandy soils of central Sundaland. To test these two nonexclusive hypotheses, we performed a floristic cluster analysis based on 111 tree inventories from Peninsular Malaysia, Sumatra, and Borneo. We then identified the indicator genera for clusters that crossed the central Sundaland biogeographic boundary and those that did not cross and tested whether drought and coarse-soil tolerance of the indicator genera differed between them. We found 11 terminal floristic clusters, 10 occurring in Borneo, 5 in Sumatra, and 3 in Peninsular Malaysia. Indicator taxa of clusters that occurred across Sundaland had significantly higher coarse-soil tolerance than did those from clusters that occurred east or west of central Sundaland. For drought tolerance, no such pattern was detected. These results strongly suggest that exposed sandy sea-bed soils acted as a dispersal barrier in central Sundaland. However, we could not confirm the presence of a savanna corridor. This finding makes it clear that proposed biogeographic explanations for plant and animal distributions within Sundaland, including possible migration routes for early humans, need to be reevaluated.


Subject(s)
Ecosystem , Trees , Asia, Southeastern , Conservation of Natural Resources , Humans , Models, Biological , Phylogeography , Population Dynamics , Soil , Tropical Climate
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