Figure 1.

Survey of the literature in databases (Scopus—first upper line of squares; PubMed—middle line with squares; and CAB Direct—bottom line with squares) with indexed keywords related to host plants and endophytes. * = Keywords were used as shown in the figure except for the PubMed database, where the use of wildcards is irrelevant in a standard search as it uses only the root of the term for the generating hits. The search was performed for the title, abstract and keywords or descriptors, where possible (i.e., in Scopus and CAB Direct). Values in squares are the number of publications. Squares are proportional to the number of publications. Interpretation of squares scaling was calculated per group of data as follows: cluster 1—endophytes and fungal endophytes, cluster 2—Artemisia and related keywords, cluster 3—Taxus and related keywords; the highest number of publications per each cluster was considered 100%. Transformation to log₁₀ was performed to reduce the skewness and facilitate interpretation of the squares.