Answers are grounded in this paper and cite their sources.
Christian Stierstorfer, Markus von Gaisberg, Annotated Checklist and Distribution of the Vascular Plants of El Hierro, Canary Islands, Spain, Englera, No. 27, Annotated Checklist and Distribution of the Vascular Plants of El Hierro, Canary Islands, Spain (2006), pp. 3-221, 2
No takes yet. Share an insight, caveat, or question.
Stierstorfer et al. (2006) studied this question.
Synapse has enriched 9 related papers. Consider them for comparative context: