Field of Science

The Paradox of Cryptic Species

A cryptic species is quite the paradox. If it is cryptic, how do you identify it as a species?

Well with cryptic species there is usually a hint. A tickle at the back of your brain. Maybe it is a species with wide morphological variation or a complex distribution that makes you wonder whether there are additional species hiding within. 

Many cryptic species are uncovered when molecular data is used to examine the relationships between species. Members of a cryptic species may seemingly look the same, but not be each other's closest relatives. And thus the real adventure begins.

Medina, R; Lara, F; Goffinet, B; Garilleti, R; Mazimpaka, V. 2012. Integrative taxonomy successfully resolves the pseudo-cryptic complex of the disjunct epiphytic moss Orthotrichum consimile s.l. (Orthotrichaceae) Taxon 61:1180-1198.

The star of the show Orthotrichum consimile.  Figure 2B from Medina et al. 2012
In this paper Dr. Rafael Medina and coauthors undertook an exploration of the moss species Orthotrichum consimile and uncovered four cryptic species hiding within. They carried out this research using the process of reciprocal illumination. They first made a detailed morphological examination of many specimens from across the range of O. consimile and detected three different morphotypes (A, B, C). Basically they were able to group the specimens into three piles based on their appearance. These observations set the stage for their molecular analyses. They then extracted DNA from representatives of each morphotype and used portions of their genetic code to build a phylogenetic tree to test the relationships between the samples. They found that the morphotypes were placed into four distinct clades (monophyletic groups). The members of A and B were each in their own clade, whereas the members of C came out in two separate clades (C1, C2). They then re-examined the specimens of group C to see if there were any features that could be used to tell them apart. After closer inspection, they found that there were a few small, but detectable differences between the specimens in C1 and C2. Thus, the morphology and molecular data were reciprocally illuminating.Based on the molecular phylogeny and the morphological differences they describe four Orthotrichum species. A more restricted Orthotrichum consimile, O. columbicum, O. confusum (this is my favorite specific epithet of the bunch!), and O persimile. 

I think that this study is a great example of morphological and molecular research complementing each other to address a question of species relationships. With morphologically austere lineages (Bickford et al. 2007), such as bryophytes, the challenge of teasing apart cryptic species may seem daunting. However, this study of Orthotrichum shows that when a systematic and detailed approach is used, uncovering cryptic species is possible even in the morphologically austere mosses.

If you are interested in reading more about Dr. Medina's research or downloading a pdf of this paper check out his page on 

Medina, R, Lara, F, Goffinet, B, Garilleti, R, & Mazimpaka, V (2012). Integrative taxonomy successfully resolves the pseudo-cryptic complex of the disjunct epiphytic moss Orthotrichum consimile s.l. (Orthotrichaceae) Taxon, 61 (6), 1180-1198

Sequoia National Park Field Guide

These are the final two videos in the series Looking Down by Lena Coleman, a graduate student at California State University Northridge.

These two are photographic field guides that teach you to identify moss and liverwort species from the Sequoia National Park. I didn't count, but I would estimate that 60 species are covered between the two videos. They are organized first by elevation and then by the substrate on which they grow. Mostly the identifications are based on features of the leafy or thalloid gametophyte, but photos of the sporophytes are also shown. 

I think that it is a really nice guide and it definitely makes me want to get out and explore the bryophytes of California. However, I am not sure how I am going to take these guides out to the field with me. Does this mean that I have to break down and get a smartphone?

First Half

Second Half

Do you have a favorite species? Though Funaria hygrometrica is the species that I study for my laboratory research, I would have to say that my favorites of the bunch are the Fissidens species. Those opposite leaves that clasp around the leaf above are such a neat shape.

If there are any issues viewing the videos above they can also be watched here (first half) and here (second half)

Identification Basics for Bryophytes Video

This the second video in the series Looking Down by Lena Coleman, a graduate student at California State University Northridge.

This video teaches the basics of identifying bryophytes. She walks through the different growth forms and puts them in the larger picture of land plant evolution. The transitions and graphics are really sharp. The different parts of the moss plants are covered in more detail, with zoomed in shots and definitions for the different terms. (One typo - Calyptra is spelled without an e.) 

The guide is good for orientating novices who are just beginning to explore the diversity of mosses. 

The video can be played by clicking on the video below or on YouTube through this link.

Mosses of Sequoia National Park

This video focuses on mosses of the Sequoia National Park in California. It is the first in a series of videos made by Lena Coleman, a graduate student at California State University Northridge. The images in the video are really great and it makes me want to get out for some hiking in the woods!

The video can be played by clicking on the video below or on YouTube through this link.

The music is nice but it is not one that I recognize. Can anyone name that tune?

Want to learn the California mosses?

If your answer to this question is yes, then you are in luck. There are some great resources out there to learn to identify mosses in California. 

One is this book California Mosses by Bill and Nancy Malcolm, Jim Shevock, and Dan Norris. This book is amazing! It has over 300 pages of color photos and covers 176 moss genera that live in California. Identification via leaves is the main focus of this book. The idea is to pull a few leaves off of a stem, place them in a drop of water on the back of your hand, and then examine them with a magnifying lens (hand lens or loupe). There are black and white images of all the leaves that show the general outline and midrib as well as unique features such as hair points or a curved margin. These drawings are sorted at the back of the book by genus and unique features. 

Another resource for moss identification in California is the California Moss eFlora. This is an online moss identification resource that includes keys to the genera and species, line drawings and photos of the taxa, and maps with species distributions. 

I am new to using both of these resources, but think that they are going to be super helpful as I explore the moss flora of California. If you have any thoughts to share on these resources feel free to leave a comment. 

February 2013 Desktop Calendar

My California moss explorations have started close to home. This is an Orthotrichum growing on the tree in my back yard. Some of the other tufts had small sporophytes topped by plicate calyptrae (calyptrae with folds). Unfortunately they resisted my photography efforts, but this little patch without sporophytes came out well.  

1 - Single click on the image to open it up in a new window. (If you use the image directly from the blog post you will lose a lot of resolution.)

2 - Right-click (or ctrl-click) on the image, and chose the option that says, "Set as Desktop Background" or "Use as Desktop Picture". The wording may vary.

3 - If the image does not fit your desktop neatly, you may have to adjust the image (Mac: System Preferences - Desktop and Screen Saver - Desktop; Windows: Control Panel - Display - Desktop) and choose "Fill screen" as the display mode of your background image.