New Scientist has an article https://www.newscientist.com/article/mg ... superstar/" onclick="window.open(this.href);return false;
They suggest that over-collection drove Aloe vera to extinction in its original and possibly restricted location. This is known to have happened to other famous medicinal herbs during the Roman Empire, such as silphion. Another fascinating observation is that leaf succulence is highly linked to the likelihood of medicinal use of a particular species of Aloe, whether the gel is used or not (see Additional File 5). In the case of Aloe vera the portability and shelf life of the leaf must have contributed to its choice as a useful medicinal herb for the trade routes of the Arabian peninsula.
I am confused as to why the authors say there are seven close relatives of Aloe vera (which they don't name directly) found in the Arabian peninsula when the trees seem to show either four or ten depending how far you take it back. Perhaps saxicola can enlighten me? The four most obvious are A. acutissima, bakeri, purpurea and yemenica. Are the other three A. benishangulana, mawii and schelpii?
A. acutissima and A. bakeri appear to be exclusively Madagascan rather than the Arabian suggested by the paper, according to both Tropicos and Succulentguide. A. purpurea appears to be from Réunion/Mauritius not Arabia. A. yemenica does appear to be from the Yemen on the Arabian Peninsula.
Just to complete my confusion A. benishangulana is from Ethiopia , mawii Malawi and schelpii, Ethiopia. The other five in the "Arabian" aloes do seem to be all from the Yemen (and some more widespread in Arabia).
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