Richard W. Spjut
October 2004, with additional comments, December 2004
Lichen Flora of the Greater Sonoran Desert Region
|Two morphologically different thalli of Niebla occurring together on rock in Baja California. Both were found by Spjut to have divaricatic acid. In the Greater Sonoran Desert Lichen Flora, these would not be differentiated; both would be considered to belong to the same species, Niebla homalea. In Spjut (1996), however, they are differentiated; the blackish-green thallus on the left is N. podetiaforma, the yellowish-green on the right is Niebla tugida.|
|This work—proposed to be accomplished in three volumes—provides a
much-needed accounting of the lichen flora in southwestern North America. In
the second of two volumes published, Nash reports ~1300 species in 700 genera
have been treated thus far.
My interest in lichen taxonomy developed from collecting samples for antitumor and anti-HIV screening from Baja California and much of the mainland US. Also, I became interested in developing a lichen flora of Baja California, an area rich in lichen species. This received encouragement from Phil Rundel and Mason Hale (see letter below from Smithsonian Institution to Dr. Spjut, 1990), while my taxonomic revision of Niebla, which included recognizing a new genus—Vermilacinia, evolved out of frustration in trying to identify material from Baja that I collected during 1985. At that time, I had not considered doing any revision work in lichens. However, each time I would visit the Smithsonian to use the herbarium to identify my collections, the Curator, Mason Hale, would appear at the herbarium cabinet where I happened to be working; Dr. Hale always seemed to advise me that the genus I was looking at needed study, and that chemistry is critical to identification of the species.
The Greater Sonoran Desert Region is defined by Nash and Gries in Vol. 1 to include not only the Sonoran Desert—as outlined by Forrest Shreve (1936, 1964), but other regions, such as chaparral, coastal sage scrub, and coniferous montane forests in southern Californica, Baja California, and Arizona, the Mojave Desert in California, Arizona and Nevada (NV portion not shaded on map), and subtropical woodland, bushland and scrub forests in Arizona, Sonora, Sinaloa, and Baja California. The range of the flora extends much further in view of new name combinations by Bowler and Marsh in Niebla for three species found only in the Mediterranean Region. Perhaps, these volumes should be titled the Greater Sonoran and Mediterranean Lichen Journal. There are many other new species and combinations reported. Keys to genera are to be found in both volumes, but those not treated in Volume 1 are indicated to appear in Vol. 2, but as discoveries are made, it has become necessary to provide addenda keys, which appear in Vol. 2. For example, Mobergia was left out of Vol. 1, but certainly included in Vol. 2-not only in the addendum key, but also in a nice photo on the jacket cover, without acknowledgment of the photographer as done for the photos on the jacket of Vol. 1. And we are told to expect more addenda in Vol. 3 as the entire flora itself continues to evolve.
Each genus includes a detailed description of its characteristics, references consulted, sometimes a commentary on the taxonomy, sometimes indicating the number of species in the genus, and following this dissertation is a key to the species and a detailed description for each one. Both volumes include occasional black and white photos exemplifying the habit of the lichen species described. These are fair as might be expected due to lichens being difficult to photograph, but, nevertheless, helpful. There are also small distribution maps for most species that are helpful. The second volume includes 24 pages of color plates, four photos to a page, that are mostly very well done, although many are from S. Sharnoff whose outstanding photos nowadays seem to appear in every American lichen book; they are inserted at the genus Niebla, which only seems appropriate, therefore, to review, besides the fact that I am familiar with Niebla taxonomy.
Included among the color photos are six that they identified as species of Niebla, but none agree with my taxonomy (Spjut 1996); for example, their (1) Niebla ceruchis is Vermilacinia leopardina in Spjut (1996), their Niebla homalea is Niebla podetiaforma in Spjut (1996), their Niebla ceruchoides is Vermilacinia ceruchoides in Spjut (1996), their Niebla polymorpha is Vermilacinia paleoderma in Spjut (1996), their Niebla procera is incorrectly identified even according to their key, it should have been Niebla combeoides, which Spjut regards as a synonym of Vermilacinia combeoides (Spjut 1995, 1996), and their Niebla robusta is Vermilacinia polymorpha. It might be further noted here that in the Lichens of North America by Brodo, Sylvia. Sharnoff, and Stephen Sharnoff, that their photo of Niebla homalea is recognized by this author as Niebla cornea, while the remaining species of Niebla depicted are all referable to Vermilacinia in Spjut (1996) without further change in the species epithet. For additional comments, see Vermilacinia page.
The keys in Vol. 1 recognize both Vermilacinia and Niebla (key by Bruce
Ryan), whereas Vermilacinia is not treated in Vol. 2, but included in
Niebla by Bowler and Marsh. Their treatment differs slightly from
their previous piece-meal publications in Phytologia and
included Nash and Riefner as authors (Bowler et al. 1994; Marsh & Nash
1994; Riefner et al. 1995). Bowler and
Marsh now regard Niebla pulchribarbara as a synonym of N. josecuervoi, while
Niebla polymorpha appears to be confused with N. robusta;
the type for N. polymorpha was not even shown when it was first described, but I did see
it during my visit to the lichen herbarium at
Arizona State University in April 1996 at which time Janet Marsh and I
reviewed many of their Niebla and Vermilacinia specimens.
Maybe it will show up in Vol. 3. As I
recall, Dr. Marsh and I had seemed to recognize Vermialcinia
polymorpha as distinct from V. paleoderma, while we both questioned
V. tuberculata as being distinct from V. ceruchoides. So what
has happened since?
Second, Bowler and Marsh argue that chemistry is not a basis for separating Vermilacinia from Niebla with reference to the diterpene (-)-16α-hydroxykaurane. Yet, Kashiwandani and Nash in the same flora justify Niebla as distinct from Ramalina by the absence of this diterpene. So it would seem that chemistry is important to distinguishing genera within the Niebla complex after-all! In further regard to Ramalina, Kashiwandani and Nash commented that Ramalina can be distinguished from Niebla by the presence of pseudocyphellae; however, the new combination made by Bowler and Marsh, Niebla crispatula, was described in detail by Krog and Østhagen (1980) to have common "marginal psuedocyphellae." The Mediterranean species of "Niebla" appear intermediate to Vermilacinia, especially in their in secondary metabolites of triterpenes and bougeanic acid with depsidones frequently present as accessory compounds, but are distinguishable as species of Ramalina by the pale pycnidia, as recognized by Kashiwandani and Nash, in contrast to the black pycnidia in Vermilacinia and Niebla. Thus, the new combinations provided by Bowler and Marsh have only blurred the generic boundaries. This was discussed in detail by Krog and Østhagen in 1980 when they questioned the generic distinction of Niebla. Spjut (1995) has since sorted out the problems and clarified the taxonomy by segregating two of the Niebla species “aggregates” into a new genus Vermilacinia.
Within Niebla sensu Spjut, Bowler and Marsh distinguish N. josecurevoi from N. homalea by chemistry; thus, chemistry is also important in the species taxonomy of Niebla. Their comparison of Niebla chemistry to that of the Ramalina siliquosa complex should only be applied to Vermilacinia cephalota, V. cerebra, and V. tigrina; it does not apply to Niebla sensu Spjut (1995, 1996). The parallel distinction was discussed in detail by Spjut (1996). Additionally, Bowler and Marsh treat Niebla homaleoides Spjut as a synonym of N. homalea, whereas Spjut had clearly pointed out that this species is related to N. josecuervoi. Thus, this revised treatment is not only inconsistent but plainly wrong.
Finally, the interpretation of "Niebla ceruchis"
as occurring in North America ignores the basic differences in the
taxonomic aggregates that Bowler (1981) himself had recognized, the
saxicolous “N. homalea group”
group,” and a corticolous group for which has been given the misapplied
name N. ceruchis. As Spjut (1996) clearly
demonstrated, Vermilacinia ceruchis does not occur in North America.
Nonetheless, if Bowler and Marsh interpret
this South American terricolous/saxicolous species, which is cleaerly allied to
V. combeoides, as encompassing all previously known corticolous
species (except N. cephalota), then all species recognized by Bowler and Marsh of the
combeoides” and corticolous groups would have to be treated as
synonyms of their Niebla ceruchis. Essentially, this
leads to recognizing just one species, Niebla homalea. This is
what Montagne concluded in 1852, and like Bowler and Marsh, Montagne had also commented
quite extensively on the variation in the genus. However, when
Bowler and Marsh expand their treatment to species of Niebla in the Canary Islands and
Madeira, then to be consistent in the taxonomic treatment, all of the
North American species fall under
Bowler, P.A. 1981. Cortical diversity in the
__________ & P. W. Rundel. 1978. Two new
__________, R. E. Riefner, Jr., P. W.
Rundel, J. Marsh & T.H.
Brodo, I, S.D. Sharnoff & S. Sharnoff. 2001. Lichens of North America. Yale University Press, New Haven and London.
Follmann, G. 1976. Zur Nomenklatur der
Lichenen. III. Uber
Hale, M. E. & M. Cole. 1988. Lichens of
Howe, R.H., Jr. 1913. North American species of the genus
Krog, H. & H.
1980. The genus Ramalina
Marsh, J. & T.H. Nash, III. 1994. A
new lichen species, Niebla
Montagne, D.M.1852. Diagnoses
phycologicae. Ann. Sci. Nat.
Nash, T. H. III, 1995. Arizona State University, Letter to Richard Spjut, Nov 15.
Nylander, W. 1870. Recognitio
monographica Ramalinarum. Bull.
Riefner Jr., R. E., P. A. Bowler, J. Marsh &
T. H. Nash III. 1995.
Rundel, P.W., P.A. Bowler & T.W.
Mulroy. 1972. A fog-induced
Rundel, P.W. and P.A. Bowler, 1978.
Niebla, a new generic name
Shreve, F. 1936. The transition from desert
_________. 1964. Vegetation of the
Sonoran Desert. Pp. 26-126
Smithsonian Institution. 1990 (Jan. 9). Letter from the Director of the Natural Museum of Natural History to Dr. Richard Spjut indicating renewal of his appointment as Associate and Collaborator, with particular emphasis on Dr. Spjut's study of the lichens of Baja California.
Spjut, R. W. 1995. Vermilacinia (Ramalinaceae,
Niebla and Vermilacinia (Ramalinaceae) from California and Baja
California. Sida, Botanical
Miscellany 14: 1–207, 11 plates.