Identification Guide
What is a Bryophyte?
Bryophytes are small, non-vascular plants that are gametophyte dominant. They lack roots and vascular tissue for carrying water through the plant. They reproduce clonally or by producing a capsule with spores, and have no flowers. Bryophytes are divided into 3 groups in separate phyla: Anthocerotophyta - Hornworts, Marchantiophyta - Liverworts, and Bryophyta - Mosses. These three groups combined are the second largest group of plants, exceeded only by, the flowering plants, the Magnoliophyta (Glime 2006-2017).
The term moss also refers to vascular plants, algae, or lichens that have similar aspect to bryophytes. Spanish moss (flowering plant), Irish moss (algae, flowering plant), reindeer moss (lichen), Pixie moss (flowering plant), or spike moss are some examples of plants that are not bryophytes.
How do I identify them?
Although some bryophytes have structures that are conducive toward identifying them with the naked eye, most will need to be examined with a hand lens (10-20x) in the field and with a microscope. Diagnostic characters to look for include where and on what it is growing; leaf shape, arrangement on stem, and presence or absence of midvein-like structure; whether it is growing in tufts or clumps, or forming a mat. Field guides and online references can then be used to put a name to the organism.
How can you Identify Bryophytes?
Identification of bryophytes can be accomplished in several ways. You can collect what you might wish to identify and question someone who might know. That may be your first step in the field, but it soon becomes tiresome for you and the people you are questioning. As in any biological discipline, learning organisms of any sort requires that you learn the words needed to converse about or describe them. These words are the basis of a sort of technical language that may become quite specific for each set of organisms. This language is how you talk about bryophytes, too. Definitions of these words are written into glossaries found in identification manuals, in on-line glossaries and are the subject of individual dictionaries.
Identification manuals come in several forms, those that are generally complete and cover all the known species of a region and those that cover only common species. Beware of the latter since they may let you down by being only partially inclusive. However, such partially inclusive texts can be a place to begin. Understand that they may not represent the universe, so to speak, where you live or are trying to study bryophytes. They may have an abbreviated protocol for identification and depend largely on use of pictures, which, of course can be extremely useful.
There are many texts covering portions of North America that will serve you well when you become familiar with the language found in identification keys and when you learn to understand illustrated renditions of bryophyte structures. In such manuals, keys are the most important means of identifying these little plants and magnification will be needed to see diagnostic structures adequately. Some resources, regional manuals and other identification guides useful for identification of bryophytes in North Carolina, are listed below. There is a growing set of useful identification resources becoming available on line.
Here is a handout providing a good overview of our bryophytes - NCBP-Bryophyte Handout
See the Links and References section for resources to identify bryophytes.
This website also has a good description for what is a moss What is a bryophyte ? As does What are bryophytes?
Bryophyte Magnification
In 1900, Abel Joel Grout, considered by many at the time to be an out-standing authority on North American mosses, authored a small book for the lay public, Mosses with a Handlens. This publication was so successful that he went on to publish Mosses with a Handlens and Microscope in 1905. Both books can still be found in some rare book corners.
Considering the increase in magnification from the first to the second book, more species of mosses could be included. Magnification is necessary during the identification of almost all bryophytes. However, quite a few species can be readily identified with minimal magnification or none, particularly if they are already known to the observer. The beginner would be seriously disadvantaged when initially trying to see or understand most bryophyte structures without adequate magnification.
Magnification can be considered at three levels, handheld lenses for use in the field, low-magnification dissecting scopes and high-magnification compound microscopes. These three types of devices allow for overlapping ranges of magnification, all necessary in the study of bryophytes. All have features useful in different areas of bryophyte magnification.
There is a variety of hand-held magnification devices. Small devices generally referred to as handlenses or loupes that slide or fold out from protective covers are most appropriate for use in the field. Magnification ranges commonly preferred in the field are from 10 to 20 times, or 10x to 20x. Sometimes handlenses come with LED’s that allow illumination of the specimen being examined. Lights are great when collecting in heavily shade areas. Be wary of instruments fitted with plastic lenses. While cheaper, plastic lenses can be scratched and may not retain their refractive quality with heavy use.
Getting used to using a handlens may take some time. Use your cheek as a brace to steady the hand that holds the instrument. Steady the hand holding the specimen against the hand holding the lens. Slowly adjust the hand holding the specimen to bring it into focus. Keep the cheek, the hand holding the lens and the hand holding the specimen in contact, all well braced. Remember that the depth of focus (the area in good focus through the lens) at higher magnifications decreases considerably. You may not easily make out the detail of a bryophyte structure because of poor focus. Try hard to keep the the plane of focus equivalent to the plane of the specimen or structure being observed.
Once you have your specimens at home or in the lab, you are ready to begin sorting them to examine more closely what you have collected. A routine of sorting, examining and identifying seems to allow for an organized means of using magnification in the lab, where the dissecting microscope is used for sorting among the collected specimens, examining structures and identifying any material that will require some preparation before being placed on a microscope slide for critical examination with the compound microscope’s higher levels of magnification.
Dissecting scopes are capable of magnifications that vary from 10x to as much as 60x. These magnifications allow for examination of gross habits and structures of most bryophytes except for the tiniest. Shapes, sizes, colors, etc. of major structures including stems, leaves and sporophytes can be assessed and/or measured. Dissection of structures for observation with compound microscope can be made. Cross sections can be cut and mounted on slides.
The compound microscope is most appropriate for examination and measurement of tissue and cell characteristics. Magnifications usually required will vary from 40x to 600x. A set of 10x to 15x ocular lenses that accommodate the eyes are customary, while objective lenses on the turet of the compound microscope might range from 4x to 60x. In some situations a good oil immersion objective is desirable.
Leaf margins, cell shapes and sizes, tissue sections, cellular details of sporophytes and gametangia and, spores and gemmae shapes and sizes are all best examined with the compound microscope. There are often structure, tissue or cell types that must be critically examined through the course of diagnostic keys, as well as cross sections to be cut for observations of tissue/cell types. With the compound microscope many characters are found that are important or required for identification of species. Without question, the compound microscope is an essential tool if you aim to gain familiarity with bryophytes.
Yes, microscopes, both types, are expensive. However, used or refurbished microscopes are readily available for much reduced prices through reputable dealers on the internet. You can benefit from the fact that some school is upgrading their scopes and trading in the old ones. Much like automobiles, new microscopes are most pricey before they leave the dealer, following which they seem to depreciate precipitously.
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