Volume XXX - 1999
The Rare Treasure of Mount Mazama Collomia
By Casey Baldwin
Mount Mazama Collomia (Collomia mazama) is a beautiful and
rare member of the phlox family endemic to Crater Lake National Park and
adjacent lands on the Rogue River and Winema national forests. It is a
perennial species primarily restricted to the open woods and meadows of
the lodgepole pine and true fir forest communities of southern Oregon's
Cascade Range. This species was discovered by the noted botanist F.V.
Coville along Dutton Creek, just two air miles from Crater Lake, in
1896. Modern day explorers can still observe a healthy population of
these plants at this site (called a type locality), though the species
is considered threatened throughout its range. There are only 55 known
populations, of which 12 (or 22 percent) occur within Crater Lake
National Park.
A Mount Mazama collomia in bloom. Photo by Casey
Baldwin.
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C. mazama is one of eleven species in the genus Collomia
found in western North America. It is herbaceous and perennial,
ranging from 15 to 30 cm tall, with broadly lanceolate leaves having
distinctive irregular teeth towards the apex. Flowers are borne in
terminal, head-like cymes, and possess funnelform shaped corollas up to
1.5 cm broad; coloration is lilac, bright purple, deep blue, or violet.
Adding to its beautiful appearance are the exerted stamens with powder
blue anthers. The inflorescence is covered with glandular hairs that
exude a slight skunky odor. Three small, black seeds are produced per
capsule and are explosively dehiscent -- where seeds have been observed
to disperse up to half a meter. Flowering occurs from June through
September.
Two other perennial, blue-flowered Collomia species occur at
high elevations in Oregon. These are C. debilis var. debilis and
C. larsenii. C. debilis can be distinguished from C. mazama
by its larger flowers (1.5 to 3.5 cm) and sprawling habit. It
is only found in central and northeastern Oregon. C. larsenii is
also distinguished by its sprawling habit, and pinnately- or
palmately-lobed leaves, as compared to the erect habit and toothed
leaves of C. mazama. Collomia larsenii occurs in the Olympic
Mountains and Cascade Range.
Collomia mazama predominately inhabits places at high
elevation (4800 to 6300 feet), where it associates with mountain
hemlock, red/noble fir, and lodgepole pine. Minor habitats include the
mixed conifer forest, the interface of meadows with incense-cedar,
and riparian areas. The largest C. mazama population found within
Crater Lake National Park is located on the middle fork of Copeland
Creek, near the Pacific Crest Trail. White fir (Abies concolor),
Red noble fir (A. magnifica-procera), lodgepole pine
(Pinus contorta), incense-cedar (Calocedrus decurrens),
and mountain hemlock (Tsuga mertensiana) are present in the
overstory, with thinleaf huckleberry (Vaccinium
membranaceum), Crater Lake currant (Ribes erythrocarpum), and
baldhip rose (Rosa gymnocarpa) in the understory. Other large
populations of Mount Mazama collomia occur along lower Bybee Creek and
southwest of Sphagnum Bog along Crater Creek, whereas smaller
populations occur along the north and south forks of Copeland Creek,
Sphagnum Bog, and upper Bybee Creek. The Dutton Creek population, along
with those between Sphagnum Bog and the Pacific Crest Trail, occur where
lodgepole pine, scattered red/noble fir, and mountain hemlock dominate
the forest canopy. In these places grouse huckleberry (V. scoparium),
two-colored lupine (Lupinus bicolor), meadow penstamon
(Penstamon rydbergii), and long-stolon sedge (Carex
pensylvanica) largely comprise the understory. The population at
Thousand Springs is the smallest (less than 35 individuals) but the most
unique in the park, occurring in the drier portion of a riparian zone
with associated huckleberry and a sparse overstory of lodgepole pine and
red/noble fir.
Mount Mazama Collomia. Drawing by Charles F. Yocum,
ca. 1951.
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Concern over the long-term viability of Mount Mazama collomia, as
well as the lack of basic biological information, prompted a cooperative
research effort. Personnel from the National Park Service, U.S. Forest
Service, and the University of Idaho worked together in developing a
comprehensive conservation strategy. At the same time, grants from Canon
USA, Stillinger Botanical, and the Mazamas assisted me with gathering
data on the plant's genetic structure, reproductive biology, demography,
and ecology. The most relevant findings are summarized in the following
paragraphs.
A genetic analysis of 20 populations from Crater Lake National Park
and surrounding national forest lands was conducted using starch gel
electrophoresis. The overall genetic diversity turned out to be low,
with only 2 of 22 loci exhibiting more than one allele. Most of the
genetic variation is contained between populations (particularly the
northern versus southern, with Red Blanket Creek being a rough dividing
line). In all likelihood, the distinction is due to random genetic
drift. This is probably due to small population sizes sometime in
the past, a characteristic common to many species of rare plants.
Populations within and immediately adjacent to Crater Lake National Park
contain the highest levels of genetic diversity within the species and
thus represent a valuable genetic resource.
Another study tracked demographics (birth, growth, death, and
reproductive success) of eight C. mazama populations that occupy
the range of habitats in which this species is typically found. Over
4,000 individuals were located, marked, and measured over a four year
period. Research results indicate that a large number of seeds may be
produced during a given year (up to 750 seeds per square meter) but the
rates of germination and survival are extremely low. No more than ten
percent of seeds will germinate the following year, with a mortality
rate of 50 percent in each of the successive growing seasons. Seedling
growth averages one centimeter per year, with flower and seed production
beginning at a height of 5-10 cm, or at an estimated age of 7-12 years.
Up to 50 percent of the plants flowering in a given season will not
flower the following year, and approximately 10 percent of the
population will be dormant for a full growing season. Additionally,
predation by deer appears to play a significant role in the population
dynamics of this species, with up to 45 percent of a population being
eaten before setting seed. Taken together, these factors indicate that
the rarity of this plant may be due to the combination of low
survivorship, slow growth rates, and predation.
Restoration efforts
According to one survey, several C. mazama populations have
been impacted by activities associated with the trail system in Crater
Lake National Park. Both seedlings and vegetatively propagated clones
are being evaluated so as to find the best way to restore these
populations. Due to the relatively slow growth rate of seedlings, it was
thought that the use of material propagated from mature plants would
result in better reestablishment. Results from the propagation of
seedlings and vegetative clones in a greenhouse environment showed that
both grow at the same rate, flowering after reaching a height of 7 cm.
Flowering is a function of plant height, whereas the growth rate seen in
seedlings is the result of environmental conditions. Field trials were
initiated in the latter part of 1997 to evaluate the establishment of
seedlings and vegetative clones on compacted and non-compacted sites in
both spring and fall plantings. The only observed difference so far is
that spring plantings have a higher mortality rate due to predation by
deer.
Efforts to restore Mount Mazama collomia within Crater Lake National
Park are promising, yet this rare plant continues to face a variety of
threats throughout its limited range. We can hope, however, that the
research and conservation efforts made by scientists, land managers, and
volunteers so far will continue making headway. Collomia mazama
is a botanical treasure, one to be enjoyed now and by future
generations.
Casey Baldwin is a doctoral candidate at the University of
Idaho and the principal author of a conservation strategy for Mount
Mazama collomia.
Drawing appeared in "The Community House," Nature
Notes from Crater Lake, 5:3 September 1932.
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