FIGURE 1.

(A) Adaxial view of different developmental stages of Ardisia crenata (Primulaceae) leaves, from left to right: Stage I (developing leaf), stage II (mature leaf), stage III (oldest mature non-senescent leaf, distinguished by its position as one of the basalmost leaves still attached to the shoot of the plant). The symbiont-harbouring glands can be seen on the leaf margins and are indicated by red arrows. (B) SEM image of a cross section of an A. crenata leaf nodule, the symbiont harbouring tissue in the centre of the gland is morphologically distinct compared to the leaf parenchyma. (C) Magnified view of the individual endophytic bacteria of A. crenata. (D) Different developmental stages of Psychotria punctata (Rubiaceae) leaves, from left to right: Stage I (developing leaf), stage II (mature leaf). The symbiont harbouring glands can be seen distributed over the leaf and are indicated by red arrows. (E) SEM image of a cross section of a P. punctata leaf nodule, the symbiont harbouring tissue in the centre of the gland is morphologically distinct compared to the leaf parenchyma. (F) Magnified view of the individual endophytic bacteria of P. punctata.