Biology
Orange-coloured patches of Trentephohlia abietina on a tree trunk along with grey-coloured crustose lichens
The worldwide distribution of Trentepohlia abietina indicates that it has a very wide ecological tolerance.
The best conditions for growth in culture are a combination of temperature from 10–20ºC and long day/short night conditions.
The red carotenoid pigment is considered photoprotective and is present in many algae growing where light levels are high.
Reproduction
This alga reproduces as fragments dispersed by wind or rain - vegetative reproduction.
The main reproductive structures are spherical or ovoid and are produced laterally or apically on the erect branches.
In Ireland, these reproductive structures are largest when produced in spring and early summer. They release biflagellate swarmers in the summer and autumn which germinate to produce new plants.
Similar reproductive structures are believed to produce gametes, but the evidence for sexual fusion remains inconclusive.
Stalked zoosporangia are known and these release swarmers which are dispersed by wind and rain.
