18 de septiembre de 2018

Another Letharia!

interesting note-- i found this in the San Bernardino NF collection notes from Kerry Knudson...
NOTES. – Letharia lupina is common throughout San Bernardino National Forest. The species is distinguished in our region by its occurrence in montane habitats at middle to higher elevations and by abundant isidia and soredia. It lacks apothecia in almost all specimens examined from San Bernardino National Forest. Letharia vulpina (L.) Hue is rare and reduced in form in southern California at elevations below 700 meters. It cannot be distinguished morphologically from L. lupina. For more information see Altermann et al. (2016).

Further study...
L. lupina and L. vulpina are very similar, and where they co-occur, they are impossible to reliably separate without genetic testing. Where their range does not overlap, the following morphological differences are recognized:

L. lupina
lemon yellow
long and sparsely-branched
parse isidia

L. vulpina
greenish yellow
abundantly branched
copious isidia

-L. lupina furthermore can be characteristically two-toned, due to the presence of bright yellow cortical patches contrasting with more greenish isidia and greenish tissues surrounding the isidia, although this is apparently not always expressed in every individual thallus.
-L. lupina tends to be higher elevation (190 m and up, warranting the common name “mountain wolf”), while L. vulpina is found in lower elevations (< 1600 m even in southern regions) with warm summers and high occurrence of fog and/or nighttime dew.
-L. lupina is far more common and more broadly distributed than L. vulpina in North America, the latter being restricted to regions west of the Rockies, and virtually absent from the Sierra Nevada.

i think that there are probibly many of the identified L. vulpina here on this project that may actually be L alpina! It appears that L. alpina is actually more ciommon here than L. vulpina.

i would say its a safe bet that if you find letharia w/o apathecia below 623 ft, its definately going to be L. vulpina, whereas if you find Letharia above 5249 feet, its definately going to be L alpina. the elevations in between are going to be more likely L alpine since it is more common than vulpina! Also look at the characturistics above. I have seen this "2 toned" coloration before and thought it was very different thn the vulpina's i was used to in the pacific NW. I think this is a great characturistic for identifying alpine! also look at the branching and overal color.

another note found..
Based on morphology and distribution, material of L. vulpina s. lato from the Sonoran region appears to include both L. vulpina s. str. (especially near the coast, and similar to European material) and the L. 'lupina' (especially away from the coast, and yellower, more highly branched, and with larger and more diffuse soralia) morph of Kroken and Taylor (2001). However, in my opinion the differences between these two morphs, as given by these authors and by Goward (1999), are not very consistent and are difficult to apply to the often poorly developed specimens found in southern California, where the distributions of the two morphs overlap. A few specimens from the San Gabriel Wilderness are much more robust and have sparsely divided main branches 2-3 (-7) mm wide with narrow branches mostly in the upper parts; in these morphs the narrow branches are either divaricately branched in scattered dense clusters, or more parallel and sinuous and concentrated towards the tips with extensive coverage by isidioid soredia concentrated on these smaller branches. These and other populations from arid areas may represent additional species (Barreno, pers. comm.).

more...
http://californialichens.org/bulletin/cals11_2.pdf

Ingresado el 18 de septiembre de 2018 por mossgeek mossgeek | 0 comentarios | Deja un comentario

17 de junio de 2018

Professional identificaiton verses online photo ID

So i have a blast identifying species from Inaturalist photos. Most of the ID's are from species i have already previously keyed in the field over the last 20 years I have been a professional botanist, lichenologist, bryologist and micologist. My brain just wants to organize everything so it is user friendly hence why I created 2 southern california projects, Lichens of Southern California and Bryophytes of Southern California. Picture identification is not the most reliable. I tend to spend a while studying the photo pulling out every characturistic I can find in order to Identify. Although most im 100% confident on because i was able to see all charactures to take through a key, there are so many more that i am using my best guess based on what those charactures i can see in the photo and not all characture needed to be conclusive. Many of these need additional time under the microscope and chemical testing in order to be conclusive on the identification. For these I try to state that it could also be X species and X species as well.

I think this site is an amazing tool for getting a large collection of usable species photos but it does lack on the 100% correctness of the species which cannot claim a "conclusively identified" species photo collection. I have suggested in the projects I curate that it is ok to guess on a species because it is a good way to remember the characturistic when you are proven wrong later. I have seen this myself when i see a yellow lichen always identified as rhizocarpon without having the characturistics of rhyzocarpon. Its like someone told a group of amatures that all yellow crustose are rhizocarpons. However, a lichenoligist like me could go through all the rhizocarpons in an area and correct them all in one fell swoop. My personal intent is to study groups of genus's within the projects and get them id'd as conclusively as I can.

Id like to share an excellant article on this subject.

Crossosoma 34(2), Fall-Winter 2008
EDITORIAL: A PLEA TO PROFESSIONALS
Historically, careers in botany were limited largely to academics and agricultural
or pharmaceutical applications. Many other people practiced (and continue to
practice) botany as an avocation rather than a career. In the United States, and
especially in southern California, certain botanical subdisciplines offer a relatively
new career path to botanists: documenting site-specific floras as baseline data
for environmental impact analyses. This profession requires special expertise in
floristics and ecological relationships. Like any profession, it requires a sound
background and adherence to professional standards.

Yet professional botanists increasingly seem willing to rely on unverified online
photographs to make the plant determinations that comprise their floristic
projects. I recently reviewed a short botanical survey report in which the
author cited CalFlora as a source for identifications, and reported Streptanthus
bernardinus (CNPS List 4) on a project site. The report included a photograph of
Caulanthus major (a locally common plant with no special status), mis-labeled
as S. bernardinus. I looked up S. bernardinus on CalFlora and found a similar
mislabeled photo. I believe that the report’s author is unfamiliar with the local
flora, did not make the effort to properly identify plants on the project site, and
relied instead on unverified photographs.

Plant identifications are made by careful reference to the floristic literature and often
by side-by-side comparison of vouchers with herbarium specimens. In southern
California, we are fortunate to have several first-rate technical identification
manuals; a variety of illustrated field guides; university libraries holding a body of
published literature dating back hundreds of years; numerous publicly-accessible
herbaria housing specimens identified and annotated by specialists; and access to
leading plant systematists, by phone, mail, or email, or in person.

All of these sources have limitations. Keys contain errors or ambiguities; field
guides are incomplete and provide only first-guesses at plant identifications;
monographs may be out of date or difficult to find; herbarium specimens may be
misidentified or may not represent the phenological state or geographic form of
a given sample; experts may be unresponsive. As professionals, we must do our
best to use these resources in any combination needed to identify our specimens.
When the identity of a specimen may affect land use decisions, we must be
tenacious in tracking down data needed for an accurate determination.

Illustrated field guides are the weakest of the resources listed above. They avoid
technical detail and rely instead on superficial picture-matching and flower color.

Yet they are extremely useful to confirm or disconfirm tentative determinations,
or to quickly seek similar plants at the level of family or genus. Good field guides
(we have many for southern California) are written, illustrated, reviewed, and
edited by experts. While they may contain some errors, these are scarce. Still, the
effective use of a field guide necessitates an understanding of its strengths and
weaknesses. As with any approach to plant determinations, effective field guide
use requires an occasional skeptical step backwards, even when an identification
is seemingly correct.

CalFlora is an online field guide written, illustrated, and edited by volunteers. It
has the strengths and weaknesses of any volunteer project. As a volunteer online
resource, it is comparable to Wikipedia. It is a fine resource for casual overview.
But neither CalFlora nor Wikipedia meet standards for stand-alone professional
research. None of us would trust a surgeon or airline pilot who used Wikipedia
alone to diagnose medical conditions or flight anomalies.

CalFlora offers many photographs, some of them verified, some not. Some of
the photographs are remarkable. Others are simply wrong. Used alone, it is
not a reliable resource. Used carefully, with an understanding its strengths and
weaknesses, and with an occasional step backwards, CalFlora can be extremely
useful.
- Scott D. White

Ingresado el 17 de junio de 2018 por mossgeek mossgeek | 4 comentarios | Deja un comentario

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