Selaginella, subgenus Tetragonostachys

[terrestrial_man]

Selaginella hansenii is one of the four native endemic species of the Tetragonostachys in California. The other three are: asprella, bigelovii, and cinerascens. Unlike the other endemics, S. hansenii is a Sierran species. Supposed populations found in the eastern watershed of the South Coast Ranges of Kern County are input errors of a collection made in the area of Black Mountain south of Table Mountain in eastern Kern County, not western Kern County! Possibly in this area: http://www.sierrafoothill.org/preserves.htm
Its range of occurrence overlaps that of S. bigelovii in Tulare County.

For basic distinguishing characteristics, click on link below
http://i152.photobucket.com/albums/s...iiCAKernp2.jpg
For general strobili occurrence on stems and rhizophore close up, click on link below
http://i152.photobucket.com/albums/s...enii2012P3.jpg
For close up leaf features, click on link below
http://i152.photobucket.com/albums/s...enii2012P4.jpg
For close up of adnation and strobili features, click on link below
http://i152.photobucket.com/albums/s...enii2012P4.jpg

[terrestrial_man]

Selaginella scopulorum, which is considered by some authorities to be a subspecies of S. densa, enters California through the Cascades and inner northern Coast Ranges, being noted as collected in the mountains southwest
of Redding. link to the Jepson Herbarium treatment
It is a wide ranging species that can be found northward into northern British Columbia. Apparently disjunct populations occur in Montana, Colorado, and New Mexico which may infer that this is not a legitimate species??

There are 3 additional pages:
Page 2
Page 3
Page 4

[terrestrial_man]

Currently I am growing just the five native species of Selaginella. However, there are five other species within the state that I will be adding in with information and pertinent links as may arise in my searching.
These five species are:
S. asprella
S. cinerascens
S. eremophila
S. leucobryoides
S. watsonii

As information on these species is rather sketchy and quality images may be
lacking I will add explanations to those images and web sites to provide more clarity and my own beliefs which may run counter to some of the information shown at such sites.

[terrestrial_man]

Selaginella asprella appears to be a species that is limited in its distribution to the mountains which border the Mojave and Sonoran Deserts of southern California. Its northernmost limit appear to be the mountains that border Antelope Valley in the Transverse Ranges. However, several maps indicate a
presence in Tulare County. I believe that this reported occurrence is in error and represents a mis-identified sample of S. hansenii. The map at the Jepson Online Herbarium shows this discrepancy.

Jepson Online

Don Davis has a number of excellent photos that he has posted at flickr on
the species and its habitat.
Habitat
Colony of the species
Close up of the species

Keir Morse has just made a fantastic series of photographs of the species found in the San Jacinto Mountains, east of Los Angeles. To see the 23 images please click on this link.

[terrestrial_man]

Selaginella cinerascens is a regional endemic that appears confined to southwestern San Diego County and adjacent northern Baja California. It is generally called Ashy Spike Moss because when it dries down it becomes a grayish color. However, it can be confused with S. asprella which is commonly called Bluish Spike Moss but which also dries down to a grayish color. For this reason I believe that currently reported occurrences of S. cinerascens on the eastern side of the Peninsular Mountain Ranges is, in fact, S. asprella. Calflora map of S. cinerascens and Calflora map of S. asprella illustrate the overlap of ranges and the general trend of S. asprella to be inland away from the ocean in the Transverse and Peninsular Ranges (its reported occurrence in Orange Co. is from 1923 and is probably S. bigelovii).

The species is currently under threat of continuing habitat loss due to human development. Researchers at San Diego State have conducted studies on its growth and reintroduction but these studies were not carried further than the following links (as far as I know). The species really needs to be cultivated and held in cultivation for reintroduction into managed (exercising full environmental control over the habitat despite natural periods of drought or unseemly weather patterns) reserves. The SDS studies can be read at:
The 1996-1997 Restoration Study
The 1997 Restoration Study
The 2000 Follow Up to the 1997 Restoration Study
Please note that in making their assessments of the vitality of S. cinerascens the students failed to consider that in developing an approach at a methodology of cultivation that they relied upon the research done upon Selaginella species that are members of the Stachygynandrum, an entirely different type of Selaginella and upon apparently techniques used in the propagation of mosses. Both are entirely unsuitable for the propagation of members of the Tetragonostachys.

Let me introduce you to this charming little plant:
Rolf Muertter has an excellent close up of a colony of the species on Flickr
while it is green! If you look carefully strobili are visible throughout the image, they are the broad leafed upright structures (part of one is visible on the bottom about 1/4 right of the lower left corner).
S. cinerascens-green
The San Diego State study generated an image of a colony when it was green and when it was dried.
S. cinerascens-green/dry states
A commonly encountered type of image of the species at CalFlora
S. cinerascens in partially dry state

[terrestrial_man]

Like the other desert-montane dwelling species of Selaginella (S. asprella, S. leucobryoides, and S. watsonii) S. eremophila inhabits fairly remote and generally inhospitable habitats in mountains which are within or bordering upon the Sonoran Desert of California, Arizona, and Baja California. Known areas of collection of the species are pinpointed on this map.
These habitats experience extreme temperature changes, even within a single day, coupled with a low rainfall profile that tends to indicate the merit of the occasional summer monsoon storm and its extensive run-off which flood over the steep
ridges across the rocky slopes in which S. eremophila can be found inhabiting the shade of boulders.

Keir Morse has recently posted a series of excellent photograhs of this remote species. Surprisingly it bears a close resemblence to Selaginella hansenii.
Be sure to click on each of the ten images to get a closer look at this rarely seen species.

[terrestrial_man]

Selaginella leucobryoides may be one of the rarest species within the Tetragonostachys. Only S. utahensis and S. viridissima may be less common.
However, the rarity may only be a matter of encounter than of actual population. S. leucobryoides occurs in mountainous areas of the eastern Mojave Desert growing in thin soils in and around rock outcrops, probably in areas where the species may find some shade during part of the day. It appears to be reported only from scattered locations. map with possible error in NW Nevada
The desolate and sparsely populated areas where the species occurs serve as a
natural barrier to knowledge of its actual range of occurrence. The seemingly disjunct collections of it would suggest that many more populations are spread out throughout the region of its overall occurrence.

Fortunately there are 3 excellent photographs of the species at CalPhoto
http://calphotos.berkeley.edu/cgi/im...0000+0212+2482
http://calphotos.berkeley.edu/cgi/im...0000+0212+2483
http://calphotos.berkeley.edu/cgi/im...0000+0212+2484

[terrestrial_man]

Of all the native Selaginellas of California, S. watsonii is perhaps the most
wide ranging species of them all. It can be found in all the states from the Rocky Mountains to the Pacific Ocean except in Washington. It appears to occur only in high montane areas south of the Canadian border. In California it is found in the Sierras from Central California southward into the Transverse Ranges towards the Salton Sea.
Map but is incomplete leaving out southwest Montana, Idaho, and Oregon populations


The attached images by Jean Pawek were taken in Mono County and provide an overview of a typical habitat for the species as well as a close up of a colony of the species and a more intimite look at the species with its obvious strobili. Some morphological traits can be detected, such as microphyll (leaf) and sporophyll (the leaf of the strobili which covers the sporangia at its base) and the bristles at the apex of both the microphylls and the sporophylls. The bristles are generally shorter than those encountered with other species and may be lacking altogether on the sporophylls.

The species appears to be localized to outcrops probably because it occurs in high mountainous regions and is subject to snow cover. The areas of its occurrence appear to have earlier snow melt off than neighboring habitats.
The following image brings home the role that the species and the members of the subgenus play in their environment: as pioneering plants that by their size and mat like growth trap debris and help in developing a shallow substrate for angiospermous plants and ferns alike to take hold in an otherwise inhospitable environment.
A habitat builder

[terrestrial_man]

These are the species of the subgenus, Tetragonostachys, of the genus Selaginella which occur within the state of California.
As you will note not all species have been given the extent of coverage that I would have provided. However, information and adequate images are lacking on most as it is. Were it not for the simple fact that I have been given several species to learn to identify I would not have been able to provide as much detail as I have. I hope you have enjoyed the presentation. It is for you not for me.
For me is the Flora of the Tetragoonostachys of the United States that I am currently developing. This is an internet only document as I make extensive use of hyperlinks to make the read and study more interesting, even fun. If anyone is interested in learning more about the Tetragonostachys then click on my name above, then my profile and message me and let me know that you would like to get this work. Currently available is a General Introduction and Introductions to 3 different groups which I identify as well as a species page, on S. bigelovii. Plus I will have to send a pdf with it to tell you how to set it up on your machine so that it will work right. At a species a month and with some 28 species to go it is going to take me awhile to finish!!! I am tentatively planning updates twice a year. My current species of interest is S. hansenii.


Attached is a PDF copy of most of the content of the introductory workbook to my flora of the Tetragonostachys. I have removed all the hyperlinks that linked to various pages within the document as well as to other workbooks (there are 3, 1 for each subgroup plus each species will be presented on its own workbook). The actual workbooks are in Excel and once done all the workbooks will be linked together so that anyone can manuever between them quite easily and links within each to allow for easy and rapid access to various parts of each
workbook. The introductory workbook is basically what you see though I had to delete parts of it to fit the size limits of this website. The subgroup workbooks have an introductory page, a page of a dichotomous key, and 3 pages of images of gross morphology, microphyll anatomy, and sporophyll anatomy of those species which I am growing and can image. All images used I have taken myself using either a digital camera or a digital microscope and are all probably enhanced to some degree or another to bring out detail. Species workbooks will focus on the ecology, the morphology, and identification images of each as I am able to dig up out of the net. Only S. bigelovii is my own material as I did the research myself. Several may have very little to offer due to lack of info on the net or lack of response by those who do have some info that they could share. I hope you find this sampler interesting.

[DanH]

Thanks for all this valuable info! This will definitely be my Selaginella reference in the future.