Fig. 2.

Stacked tracings of section profiles showing the distribution of the mistletoe endophyte in the median region of a dormant Douglas fir apical bud with host outlined in green and mistletoe cells highlighted in red. (A) Tracing representation of a single median longitudinal section. (B–I) Serial tracing representations, at 10-μm intervals, are stacked to illustrate the pattern of distribution of the endophyte in the host. In (I) note the presence of the mistletoe in primordial leaves and its limitation to the cortex of the host apical bud elsewhere. Scale bars = 250 μm.