BRYOPHYTES OF BRITISH COLUMBIA
Oregon beaked moss (Kindbergia oregana), photo
by Brian Klinkenberg
Dr. Wilf Schofield
Past Curator of Bryophytes
University of British Columbia Herbarium
To visit the E-Flora BC atlas pages for mosses, click here.
To visit the E-Flora BC atlas pages for liverworts and hornworts, click here.
"Bryophytes" is a term of convenience that includes
mosses, liverworts and hornworts. The mosses encompass several
evolutionary lines: peat mosses (Sphagnopsida), valved mosses
(Andreaeopsida), puzzle mosses (Takakiopsida) and "true" mosses
(Bryopsida). Sometimes the hair-cap mosses (Polytrichopsida) are
separated as an evolutionary line independent of the true mosses. The
liverworts (hepatics) possess two distinctive evolutionary lines:
the Jungermanniopsida (predominantly leafy, but also some thallose
liverworts) and Marchantiopsida (complex chambered thallose liverworts). The
hornworts (Anthoceropsida) are usually treated as a very distant
evolutionary line. All of these evolutionary lines are present
in British Columbia.
A simple definition of "bryophytes" denotes
a green plant in which the sexual generation (gametophyte) is usually
perennial and the sporophyte is largely dependent on the gametophyte
for its survival and maturation. In bryophytes, the sporophyte
produces a single sporangium while the gametophyte may bear several
sporophytes. Sex organs are antheridia that produce motile sperms
and archegonia in which each produces a single non-motile egg. Liquid
water is necessary for fertilization.
In bryophytes, the mature gametophyte is generally
leafy, but can be strap-shaped, or thallose. In most gametophytes,
growth is indeterminate. Neither gametophyte nor sporophyte has
a complex vascular system that is as well-developed as in the vascular
plants, although they may have a system that conducts water and
nutrients for growth and reproduction.
Moss-covered logs, Queen Charlottes Island, photo by David Blevins.
In British Columbia reasonable estimates indicate
the following diversity of genera and species of bryophytes:
This means that British Columbia possesses the
richest diversity of any political division in Canada. It is also
greater than the combined bryoflora of all of the United States
west of the Rocky Mountains. This diversity is the result of the
considerable environmental diversity of the province, combined
with the historical circumstances that led to the assemblage of
floristic elements from adjacent areas as well as the survivors
of elements of pre-glacial time.
Identification of bryophytes involves the utilization
of microscopic features. This increases the number of characters
for discrimination. With experience, it is possible to recognize
most genera and many species based on features visible in the field.
However, for confirmation of identification, recourse to a microscope
is necessary for many species.
Bryophytes, as with all other organisms, show
some polymorphism, and this is often exaggerated in extreme environments. The
variability is greatest in the gametophyte. Poorly developed specimens
often mimic similar species and genera, therefore caution is necessary
in applying names.
Lung liverwort (Marchantia polymorpha)
with male receptacles,
photo by Alex Fraser Research Forest.
Collecting bryophytes is relatively simple. Rules
to be followed include the collection of a reasonable sample of
material, cleaning the specimen before drying, and in the case
of liverworts, recording details of some microscopic features from
the fresh material where these features disappear in dried specimens
(e.g. colour, oil body number and form per cell, thallus anatomy). Details
of the habitat can contribute features useful in determination
(e.g. epiphytic, on rock, and kind of rock, soil, in water, etc.).
Specimens are air-dried (not pressed) and spread
so that they are easily accommodated in a packet approximately
10 cm x 14.5 cm.
Labels should record the geographic locality
where the specimen was collected (including approximate latitude
and longitude), elevation above sea level, nature of habitat (including
general vegetation), date collection was made, and the name of
the collector. Ultimately the determination of the plant is also
on the label.
Crane's-bill moss (Atrichum selwynii), photo by Rod Innes.
Storage of dried specimens is simple because
insect damage is usually minimal, particularly when the specimen
is cleaned. Extraneous soil should be removed because this may
erode the specimen each time the packet is handled, and it makes
the specimens "dirty" and more difficult to determine.
Collecting specimens should always observe conservation
ethics. Never collect the entire colony of a species. Indeed,
it should not be apparent that a collection has been taken, and
a "scar" left behind. A collection, however, needs to contain
enough material to be dissected while the determination is made,
and sufficient should remain in the packet to document the specimen
for the collector.
In British Columbia, the major collection of
bryophytes is housed in the Herbarium of the Department of Botany
at the University of British Columbia. This collection is available
for consultation during normal working hours. Well-prepared and
documented specimens are welcome as gifts to the herbarium, especially
when they come from sites that are remote and difficult to access.
Grimmia dry rock moss (Grimmia trichophylla), photo by Steven Joya.
At the University of British Columbia, an introductory
course on bryophytes is offered each year. Registration is limited
and the course has proven to be popular for many years.
To learn bryophytes on one's own, there are
two books that have been written for amateurs, and that are designed
for the British Columbia flora:
Schofield, W. B. 1992. Some Common Mosses of
British Columbia. Royal BC Museum Handbook. Queen's Printer,
Victoria, BC. 394 pages. Illustrated.
Schofield, W. B. 2002. Field Guide to the Liverwort
Genera of Pacific North America. Global Forest Society and University
of Washington Press, Seattle. 228 pages, Illustrated.
These two books direct the serious student to more comprehensive literature and serve as an introduction rather than a comprehensive treatment.
As with all organisms in the province, bryophytes
are threatened by human disturbance or destruction of the environment. In
consequence, some bryophytes are more widespread than they would
be without such disturbances. Most, however, have had their abundance
restricted. Indeed, a few have been extinguished from the provincial
flora within a brief period of time.
To view currently available bryophyte atlas pages, visit our Species Search Page. Note that many moss and liverwort species do not have atlas pages at this point.