Fog Lichens of the California Coast

Fog lichens (Niebla spp.) are a large, distinctive genus, closely related to Ramalina. They are pale bushy lichens that grow amost exclusively on rocks on bluffs along the California and Chilean coast. (There is one common California species that grows on trees, N. cephalota, but it is quite distinctive and not likely to be confused with any Ramalina.)

There are quite a number of species described from the coast of California and Baja California, where the cold Alaskan current meets warm moist air from the Pacific and creates regular heavy morning fogs. This phenomenon provides reliable moisture for an entire community of lichens throughout the so-called "fog-belt".

I have only personally seen seven species, which are covered below:

• N. cephalota
  
• N. ceruchoides
  
• N. combeoides
  
• N. homalea
  
• N. laevigata
  
• N. polymorpha
  
• N. procera
  

Here is a gallery of representative photos of all all seven of these species.

Here is a rough key to the seven species I've studied:

• bluish-sorediate, almost always on trees ... N. cephalota
  not sorediate, on rock
  	stems essentially round
  		stems simple and short ... N. combeoides
  		stems branched and long
  			stems fine and Cladina-like ... N. ceruchoides
  			stems stout and less branchy ... N. procera
  	stems flattened to strongly angular
  		stems gnarled and ugly ... N. polymorpha
  		stems smooth or at most faceted
  			stems mostly smooth and shiny, medulla with uniform texture ... N. laevigata
  			stems mostly faceted and dull, medulla with thickened "strands" ... N. homalea

Note that there are three additional species in southern California which I have not had the pleasure of studying yet:

• N. isidiascens		corralloid isidiate; Channel Islands and Baja
  N. robusta		thick spongy stems; endemic to Morro Bay
  N. tuberculata		like a coarse N. ceruchoides, but thicker and tuberculate; endemic to Morro Bay

N. cephalota

Wow, this looks different than all the hundreds of others I saw.

The lower one is not sorediate; is it just a young one?

N. ceruchoides

N. combeoides

N. homalea

N. laevigata

N. polymorpha

N. polymorpha:

(the one on the right)

N. procera

N. procera:

Combinations:

N. combeoides and N. ceruchoides

N. combeoides and N. homalea

N. homalea and N. polymorpha

N. homalea and N. procera

N. homalea and N. laevigata

N. homalea and N. laevigata

References:

• Bowler, P.A. & J.E. Marsh. 2004. Niebla in Lichen Flora of the Greater Sonoran Desert Region. Vol. 2, Nash et al. eds. Lichens Unlimited. Tempe, Arizona.
• Brodo I., S. Sharnoff & S. Sharnoff. 2001. Lichens of North America. Yale University Press. New Haven and London.