Chamaedaphne calyculata (L.) Moench
Mar–Apr ; Jun–Oct . Not seen in Shaken Creek Preserve by the senior author. Specimens seen in the vicinity: Holly Shelter: Fox 158 (NCSC!); Sandy Run [Hancock]: Taggart SARU 15 (WNC!). [= Cassandra calyculata (L.) D. Don sensu RAB; = FNA, Weakley]
General: Heath family (Ericaceae). Native perennial, evergreen shrubs 0.3-1.5 meters tall, the stems covered with tiny brownish scales. Leaves are alternate, oblong to elliptic, 1.5-5 cm long, finely toothed, the lower surface covered with tiny brownish scales, becoming smaller and positioned to the upper side of the stem towards the branch tips. The flowers are white, urn-shaped, 6-7 mm long, hanging and arising from one side of the terminal inflorescence, solitary in the axils of the small leaves. Fruits are depressed-globose, woody, gray-brown capsules, persisting through the winter. Common name is in reference to the tough, evergreen leaf.
Variation within the species: several varieties have been recognized within leatherleaf in North America, based primarily on differences in leaf size and shape (see Fernald 1950). These taxa are currently regarded as within the limits of continuous variation of the species and are not formally recognized.
Distribution: Circumboreal; northern North America from Alaska and Yukon and all of Canada (except Franklin) to the easternmost provinces, in the US in the Great Lake states and the Northeast, disjunct and rare in Maryland, North Carolina, and South Carolina.
Regularity: Regularly occurring
Regularity: Regularly occurring
. Its distribution extends southward through the Lake States and
the northeastern United States [25,70].
Occurrence in North America
NJ NY NC ND OH RI VT WI AB BC
MB NB NF NT NS ON PE PQ SK YT
Leatherleaf occurs in practically all boreal bogs as well as in swamps, lake and stream margins, sedge fens and meadows, black spruce muskegs, and vernal ponds and shrub swamps in pine barrens, usually growing on wet, strongly acidic sphagnum mats over water. It may form thickets as a dominant species in shrub associations in some bogs. It is found at elevations up to 1600 meters. Flowering: April-June from buds formed the previous season; fruiting: June-January.
Leatherleaf is a native evergreen shrub that grows up to 4.9 feet (1.5
m) tall [25,43]. Its woody rhizome extends down an average of 12.6
inches (32 cm) into organic matter . Leatherleaf has many branches
and forms dense thickets of up to 18.6 stems per square foot (200
stems/sq m) [10,33]. Average basal diameter of leatherleaf stems is
0.27 inch (0.68 cm) . The one-sided racemes have 1 to 15 or more
flowers that form persistent, many-seeded capsules [10,43,65].
Leatherleaf is a true bog species and is found in practically all boreal
bogs . It occurs in lowland sites, treed or treeless bogs,
peatlands, sedge fens and meadows, black spruce muskegs, and kettle pond
edges [2,19,55,59]. It is found at elevations up to 5,300 feet (1,615
Sites are often poorly drained or have standing water [48,63].
Leatherleaf is acid tolerant and usually occurs where the pH is less
than 5; it needs acidic conditions to become dominant [11,38,66]. It
commonly occurs in drier areas on sedge mats that may be floating or in
wet peat that is up to 43 feet (13 m) thick [12,16,38,55,83].
Leatherleaf is found on very moist ombrotrophic or minerotrophic sites
with low nutrients [3,4,7]. It occurs on substrates such as thin till
overlain with sandy loam or fine loamy clays with varying depths of
humus, or on entirely organic substrates [7,30,43]. Permafrost is often
discontinuous and can be shallow where leatherleaf grows [6,8,58].
Leatherleaf is found in maritime to continental climates with extreme
seasonal variations in temperature [8,34]. Leatherleaf grows poorly on
exposed sites with severe winters [16,33].
Key Plant Community Associations
Leatherleaf is a dominant shrub in seral dwarf-shrub wetland communities
[15,16,48]. Leatherleaf occurs in pure stands on floating mats and in
mixed stands that are grounded . Leatherleaf associations are the
most extensive communities in the bogs of the Lake States. Several
subtypes of leatherleaf associations have been described for New England
peatlands . Sphagnum-leatherleaf community types have been
described for this region and Canada . Leatherleaf is usually
present in the tall-shrub community types of bogs or heathlands [20,76].
In central and northern Canada, leatherleaf has been included in various
open black spruce (Picea mariana) vegetation types [17,43,49,73].
Leatherleaf is named as a dominant or indicator species in the following
(1) Ecology of peat bogs of the glaciated northeastern United States:
A community profile 
(2) Community classification of the vascular vegetation of a New
Hampshire peatland 
(3) Plant communities of Voyageurs National Park, Minnesota, U.S.A. .
Species associated with leatherleaf that are not mentioned above are
codominant shrubs such as bog kalmia (Kalmia polifolia), sheep laurel
(K. angustifolia), bog labrador tea (Ledum groenlandica), blueleaf
bog-rosemary (Andromeda glaucophylla), bog cranberry (Vaccinium
oxycoccos), and sweet gale (Myrica gale) [20,48,55,73,76]. Other
species occurring with leatherleaf are roundleaf sundew (Drosera
rotundifolia), pitcherplant (Sarracenia purpurea), and sedges (Carex
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
More info for the term: bog
K093 Great Lakes spruce - fir forest
K094 Conifer bog
K095 Great Lakes pine forest
K096 Northeastern spruce - fir forest
K106 Northern hardwoods
K107 Northern hardwoods - fir forest
K108 Northern hardwoods - spruce forest
K110 Northeastern oak - pine forest
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
FRES10 White - red - jack pine
FRES11 Spruce - fir
FRES19 Aspen - birch
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
1 Jack pine
5 Balsam fir
12 Black spruce
13 Black spruce - tamarack
19 Gray birch - red maple
21 Eastern white pine
37 Northern white-cedar
45 Pitch pine
97 Atlantic white-cedar
107 White spruce
Habitat & Distribution
Leatherleaf reproduces by seed and vegetatively by rhizomes. Seed set is usually high (50-95%) when the flowers are open-pollinated but low (1-15%) when flowers are self-fertilized. After cold stratification to break dormancy, the seeds germinate on sphagnum or sedge mats. Moist sphagnum surrounding leatherleaf shoots, roots, and rhizomes causes vigorous vegetative growth.
Leatherleaf is the first shrub to enter a bog after sphagnum is established and it is a primary species in extending the bog mat. It remains characteristic of the mature and late stages of moss/low ericaceous shrub communities as open water disappears and may remain dominant for 50 years in some communities. Leatherleaf is shade intolerant and begins to thin as tall shrubs or bog forest species such as tamarack (Larix laricina) and/or black spruce (Picea mariana) establish.
Persistence of leatherleaf in bogs over long periods has been attributed to its regeneration following recurrent fire, which is a primary factor in maintaining early successional stages in these communities. Leatherleaf may show a strong increase in stem density following spring burning and may be only slightly injured by summer or autumn fires. Leatherleaf probably survives severe fires because rhizomes are deep in water-saturated substrates and its root crowns and stems are matted in debris.
Division is the most successful method of propagation for leatherleaf. Plants may be divided in early fall, planting each rooted clump as a new shrub. Transplanting in summer or autumn stimulated shoot production more than spring transplanting. The ends of shoots also may be bent down to the soil and layered. Young plants should be partially shaded.
Flower-Visiting Insects of Leatherleaf in Illinois
(bees suck nectar primarily, while flies suck nectar or feed on pollen; the flowers are pollinated primarily by bees; observations are from Small and Reader)
Apidae (Apinae): Apis mellifera sn fq (Rd); Apidae (Bombini): Bombus spp. sn fq (Rd), Bombus affinis (Rd), Bombus bimaculatus fq (Rd), Bombus impatiens (Sm, Rd), Bombus perplexus fq (Rd), Bombus sandersoni (Sm), Bombus ternarius (Sm, Rd), Bombus terricola fq (Rd)
Halictidae (Halictinae): Augochlorella sp. (Rd), Lasioglossum sp. cp fq (Rd); Colletidae (Colletinae): Colletes inaequalis sn fq (Sm, Rd); Andrenidae (Andreninae): Andrena spp. sn cp fq (Rd), Andrena bradleyi sn fq (Sm), Andrena carlini sn fq (Sm), Andrena mandibularis sn (Sm), Andrena regularis sn (Sm), Andrena vicina sn fq (Sm, Rd)
Syrphidae: Eristalis sp. (Rd), Helophilus fasciatus (Sm), Melanostoma sp. (Sm), Sphaerophoria sp. (Sm), Volucella sp. (Rd); Bombyliidae: Bombylius sp. (Rd); Muscidae: Unidentified sp. (Rd), Spilogona fatima fq (Sm)
Fire Management Considerations
Leatherleaf is a flammable shrub; crowning or foliage scorch is common
with leatherleaf in the understory in the pine swamps or lowlands of New
Jersey . Fuel loading that was predominantly leatherleaf and bog
labrador tea in cutover areas of black spruce was estimated at 15 to 25
tons per acre (33-56 t/ha) in the Blackduck Burns, Minnesota .
Plant Response to Fire
Leatherleaf was only slightly injured by summer or autumn fires in New
Brunswick. Following spring burning, leatherleaf showed a strong
increase in stem density; apparently, it had not yet depleted its
reserves and was able to support new growth. Preburn and postburn
percent relative abundance (stem density) after spring, summer, and
autumn fires was as follows [26,29]:
Season of Postburn
burn Preburn 1 month 3 months 5 months
Spring 28 42 13 --
Summer 30 29 29 17
Autumn 36 32 -- --
Ten years after a lightning fire in Alaska, leatherleaf was present in
low amounts on disturbed firelines and in one burned site . It was
present at 0.7 percent frequency in burned and at 2 percent frequency in
unburned areas 20 to 24 years following fire in the Northwest
Territories . In northern Quebec, leatherleaf occurred 30 years
after fire at 21 to 31 percent frequency in lowland boreal black spruce
forest and at 1 to 20 percent in forest-tundra sites . Leatherleaf
had about 40 percent frequency 94 years following a high-severity fire
in central New York .
Immediate Effect of Fire
because rhizomes are deep in water-saturated substrates and its stems
are matted in debris [28,33]. Surviving root crowns and rhizomes
Rhizomatous low woody plant, rhizome in organic mantle
Surface rhizome/chamaephytic root crown
Rhizomatous shrub, rhizome in soil
Secondary colonizer - off-site seed
Leatherleaf's persistence in communities over long periods of time has
been attributed to its regeneration following fire . Its rhizomes
are buried deep in the mineral soil and survive all but the most severe
fires . Depth of rhizomes and season of fire affect leatherleaf
shoot growth and recovery. Leatherleaf rhizomes were collected in
spring, summer, and autumn and subjected to wet heat treatments from 113
to 140 degrees Fahrenheit (45-60 deg C). All autumn-collected rhizomes
died after treatment. Summer-collected rhizomes produced fewer shoots
than spring-collected; both had significantly (p less than 0.05) fewer shoots than
the controls .
Bogs are usually too wet to burn except during drought . Fire is a
primary factor disrupting boreal treed bog succession; leatherleaf
invades after fires remove the tree associations [9,22,28,33].
Recurrent fires at approximately 50-year intervals in New England
leatherleaf bogs or on peat surfaces controls tree invasion . Fire
recurrence in a New Brunswick bog was 370 years .
More info for the terms: bog, sere, shrub, shrubs
Facultative Seral Species
Although leatherleaf is not a pioneer mat former, it is a primary
species in extending the bog mat [11,16,22,62]. It is the first shrub
to enter a bog community after sphagnum is established [11,53].
Leatherleaf is characteristic of the mature and late stages of moss-low
ericaceous shrub communities as open water in a bog sere disappears. It
may dominate for 50 years in some communities [11,18,31].
Leatherleaf is shade intolerant [53,77]. Leathleaf stands begin to thin
as tall shrubs or bog forest species such as tamarack (Larix laricina)
and/or black spruce establish [11,33,35,63,73].
Moist sphagnum surrounding leatherleaf shoots, roots, and rhizomes
causes vigorous vegetative growth [5,26]. Sphagnum grows on leatherleaf
stems and branches but does not inhibit growth [12,18]. Ice will break
up leatherleaf shrubs, resulting in rapid expansion of colonies .
Leatherleaf establishes in windfall areas .
Leatherleaf seed set is usually high (50 to 95 percent). Seed set
decreased when insects such as bombus bees were excluded from flowers.
When self-fertilized, leatherleaf has low seed set (1 to 15 percent)
. Leatherleaf seeds germinate on sphagnum or sedge mats .
Growth Form (according to Raunkiær Life-form classification)
Life History and Behavior
Molecular Biology and Genetics
Barcode data: Chamaedaphne calyculata
Statistics of barcoding coverage: Chamaedaphne calyculata
Public Records: 3
Specimens with Barcodes: 13
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Endangered Species Protection Board .
Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status, such as, state noxious status and wetland indicator values.
Leatherleaf greatly increases following clearcutting; leatherleaf and
other shrubs can suppress black spruce on medium to poor sites . In
Minnesota, leatherleaf and other shrubs rapidly increased after tree
harvest; however, restocking was not affected by shrub density 4 to 6
years after harvest . Despite dense leatherleaf in a black spruce
swamp in Ontario, relative regeneration rates of black spruce were high
. There was no difference in stocking rates on nine burned and
unburned cutover black spruce sites in northern Minnesota; seedbed cover
by leatherleaf and bog labrador tea was at acceptable levels .
Control of leatherleaf by herbicides has been discussed .
Aboveground biomass of leatherleaf was estimated at 136.7 pounds per
acre (122 kg/ha) for wildlife browse and ground fuels in open black
spruce bogs in Nova Scotia .
Transplanting leatherleaf in summer or autumn stimulated shoot
production more than spring transplanting .
Cultivars, improved and selected materials (and area of origin)
Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”
Leatherleaf greatly increases following clearcutting. Although leatherleaf and other shrubs can suppress black spruce on medium to poor sites, restocking and regeneration of trees may not affected by shrub density after harvest on other sites. Stocking rates were about the same on burned and unburned cut-over black spruce sites in northern Minnesota.
When used for rehabilitation or revegetation, natural growth of leatherleaf can be aided by transplants of sphagnum mats containing live plants.
Relevance to Humans and Ecosystems
Value for rehabilitation of disturbed sites
Leatherleaf reclaimed large areas in raised bogs in the eastern United
States that had been denuded by commercial peat removal over the past 4
to 92 years . Seven years after powerline construction in a treed
bog in northern Manitoba, leatherleaf had two times more biomass than
other shrubs present. It had a frequency of 78 percent in disturbed
areas and 94 percent in the control . In the Pinhook Bog of
Indiana, sphagnum mats containing leatherleaf were successfully
transplanted to other bog areas that had been killed by runoff from
stockpiled road salt .
Importance to Livestock and Wildlife
Leatherleaf is browsed and used for nesting by wildlife. It was a minor
part of white-tailed deer winter browse in New Jersey . Leatherleaf
was consumed in small amounts by caribou in Michigan and northern Canada
[14,61,67,69]. Sharp-tailed grouse browsed leatherleaf twigs during the
winter in Wisconsin . Moose occasionally browsed leatherleaf from
June to November on the Kenai Peninsula, Alaska . Mallards nest in
leatherleaf in North Dakota . Leatherleaf occurred in cover types
used year-round by ruffed grouse .
August in southeastern Manitoba had 7.5 percent crude protein, 48.1
percent acid detergent fiber, and 49.3 percent dry matter digestibility.
One-year-old leaves had slightly more crude protein (8.0 percent) and
less acid detergent fiber (33.4 percent) and dry matter digestibility
(44.3 percent) .
Leatherleaf reclaimed large areas in raised bogs in the eastern United States that had been denuded by commercial peat removal. The species is used for nesting and cover by wildlife, including mallards and ruffed grouse. It is a part of browse for sharp-tailed grouse, white-tailed deer, caribou, and moose.
Chamaedaphne calyculata, leatherleaf, is a shrub in the plant family Ericaceae and the only species in the genus Chamaedaphne. It has a wide distribution throughout the cool temperate and subarctic regions of the Northern Hemisphere.
It is a low-growing shrub up to 1.5 m tall. The leaves are alternately arranged on the branch and elliptical to oblong shaped, 3–4 cm long, thick and leathery, with minute scales and lighter coloration on the underside, and an entire or irregularly toothed margin. They are evergreen but often turn red-brown in winter. The flowers are small (5–6 mm long), white, and bell-like, produced in panicles up to 12 cm long. The species site is restricted to bogs, where they naturally form large clonal colonies.
The name Chamaedaphne comes from the Greek for "ground laurel"; the common name comes from its tough, leather-like leaf.
Names and Taxonomy
Comments: The genus name Chamaedaphne has been nomenclaturally conserved; the genus containing these plants has sometimes been called Cassandra instead.
The currently accepted scientific name of leatherleaf is Chamaedaphne
calyculata (L.) Moench. It is in the heather family (Ericaceae)
[25,36,44]. Recognized varieties are :
C. c. var. calyculata
C. c. var. angustifolia (Ait.) Rehd.
C. c. var. latifolia (Ait.) Fern.
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