a,b, Environmental (n = 29 biologically independent samples) and clinical (n = 29 biologically independent samples) isolates of A. fumigatus strains plotted for morphotype characteristics (furrowing and percentage vegetative mycelia) when grown at 0.2% O2 (a) or 21% O2 (b). c,d, Two-way ANOVA shows oxygen tension significantly contributes to the variation of colony furrowing (31.67%, P < 0.0001) (c) and PVM (55.77%, P < 0.0001) (d) in clinical (n = 29 biologically independent samples) and environmental (n = 29 biologically independent samples) strains. Dashed lines indicated the mean values per condition; error bars indicate s.e.m. (centre). e, Representative isolates with an increased PVM (white) and furrowing when cultured at 0.2% O2 versus 21% O2. Images are representative of three biologically independent experiments. f, Example clinical strains that adopt H-MORPH during growth at 21% O2 (closed blue circles in b, c and d). Images are representative of three biologically independent replicates. g, Representative side-view slices of submerged fungal biofilms from A. fumigatus H-MORPH clinical isolates in f. h, Quantification of vertical alignment of filaments as a function of biofilm depth. i,j Representative side-view slices of submerged fungal biofilms of AF293 and the H-MORPH EVOL20 at 21% O2 (24 h) and 0.2% O2 (36 h) (i) with vertical alignment quantification (j). For h and j each lane is a representative alignment from a minimum of three independent biological replicates. Biofilm images are sample volumes of approximately 300 µm (height) × 500 µm (length) × 200 µm (width) and represent a minimum of three biologically independent experiments.