Near Puerto Catarina,
Spjut & Marin 13046

Punta Cono, Spjut &
Marin 11512, Apr 1990

Near Puerto Catarina,
Spjut & Marin 13053

     During the taxonomic study of Niebla, prior to Spjut (1996), an intense effort was made on a number of occasions to justify the Guadalupe specimens collected by Palmer (US) and Weber & McCoy (COLO, US) as belonging to N. caespitosa, as defined by a type from San Clemente Island (Santesson 18043. COLO, US), and by other collections from Baja California, but this simply would not work so N. dilatata was kept as a distinct species.  Since I had not collected on Isla Guadalupe, I did not acquire any familiarity with the species at that location, and because the material of N. dilatata was at the Smithsonian Herbarium (US), and not in my collections, it was put aside and sort of out of mind.

     In addition to observations in the field on the ecology of Niebla spp., photos of specimens in the field were invaluable to making decisions in resolving taxonomic problems (Spjut 1996).  Moreover, a specimen in the field does not appear the same it does in the press.   It was the collections and photographs of lichens at Puerto Catarina during 1994, just prior to publication of Spjut (1996), that raised questions about the circumscription of N. caespitosa, and it was not until later that I realized N. dilatata occurs on peninsular BCN.  A few specimens that I deposited at US early in the study, that were determined as N. podetiaforma—possibly reidentified N. contorta or N. undulata—may be considered N. dilatata.  I have not gone back to check.

     Niebla dilatata was initially distinguished by having a cortex of intermediate thickness, 75–120 µm thick, as compared to N. caespitosa and related species in Baja California, generally less than 75 µm thick, and other species on Isla Guadalupe and California in which the cortex on portions of the thallus exceeded 125 µm thick.  I was never happy with this distinction.  Had the Baja collections exhibited a more yellowish cast to the cortex, as often seen in N. podetiaforma, I may have realized its occurrence on the Baja peninsula sooner.   Color is often a useful character for distinguishing species of lichens, but in Niebla, color differences is more of a distraction to species identification as most species vary in color from one thallus to another, generally from bluish yellow-green to strongly greenish yellow.