Identification notes
In high rainfall districts, this is usually a frequent and easy to recognise species and it can form large populations on well-decayed fallen trees. Problems can arise, however, in peripheral, slightly warmer/drier areas where R. palmata is just about possible but unlikely.
R. chamedryfolia and R. multifida also grow on dead wood and can adopt odd palmata-like growth forms and then care must be taken to identify plants correctly. This is relatively straightforward (microscopically) if thalli have gemmae: R. palmata has narrower gemmae than both R. chamedryfolia and R. multifida. If gemmae are lacking, the presence of oil-bodies in most epidermal and marginal cells in the thallus should rule out R. multifida but not R. chamedryfolia, but they may be hard to detect.
If plants are sterile, R. palmata has narrower epidermal cells than R. chamedryfolia. If reproductive structures are present, do collect them because they will make identification of these odd forms much easier!
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