-10- lypodium australe may be called a true epiphyte. In addition, the rotting trunks of chestnut and alder, are often hidden by shrubs of Rhododendron ponticum, Vaccinium arctostaphylos and by some shadow-resistant small herbaceous plants, mostly grasses. A typi- cal feature of tropical and subtropical trees is the presence of buttresses at the base of trunks. Such structures can be seen on beech trees growing on steep slopes in the forests of Mtirala and in other forests of the coast. As has been mentioned earlier, subtropical appearance of the Colchic forest is imparted by the evergreen understorey, too. Here the most significant are members of the families Ericaceae, Vaccii- niaceae and Rosaceae that, in the depths of the gorges, become tree-like with trunks creeping along the steep slopes. Ilex imeretica can be found more frequently in the under- storey on Mt. Mtirala than in the Botanical Garden. But luxuriant growth of the herbaceous cover is greatly reduced by such a dense undergrowth. Here we find only those herbaceous species with a high shade resistance; for example, Ruscus hypophyllum, Paris in- completa, Phyllitis scolopendrium, Polystichum woronowii. The clo- sfer you approach the Korolistskali River and its multiple tributaries, the darker and the damper is the forest; trunks of Laurocerasus exceeding one metre in circumference trail over the river-beds and beside them tower well-proportioned trees of Alnus barbata; Rhododendron ponticum disappears from the under- storey when the humidity increases. The herbaceous flora also gives way to more moisture-resis- tant ferns and especially to mosses that cover both the surface of the soil and the rocky outcrops, as well as the trunks of Al- nus and Laurocerasus which are always wet with spray. In one such damp tributary of the Korolistskali, approximately at 300 or 350m elevation, above the village of Chaisubani, the moss-like fern Hymenophyllum tunbridgense was found under conditions similar to those of other localities in Adjaria - on wet mossy covered rocks and the moss-grown trunks of Laurocerasus (or, rarely, Alnus) over the river-bed. Farther along, our route passes through beech forest, which is more typical on the sea slopes of Mt. Mtirala at 950 to 1300m.