Oceanspray is a moderately long-lived, moderately fast growing perennial shrub of the Rose family. It is native to western North America from British Columbia to southern California including areas of Montana, Colorado and Arizona. Multiple arching stems achieve 6 to 20 feet with the taller specimens found in shade or nearer the coast. The deciduous, alternate leaves are oval to triangular with deep veins and shallow lobes plus very fine teeth. They are green above and dull green beneath due to fine hairs and turn reddish in fall. Drooping, 4 to 7+ in. clusters of very small creamy white, sometimes pinkish flowers turn to beige then brown and often persist through winter. Fruit develops in mid to late summer and consists of five tiny, hairy, light yellow achenes (dry, one-seeded fruit) per flower. The bark is red-grey and peels from older stems.
Adaptation and Distribution: Oceanspray performs well in shade or full sun and is adapted to course, medium and fine textured soils with pH 5.0 to 7.5. Ranging from sea level to 7000 ft., this species has moderate drought tolerance and low fertility requirements. Oceanspray is abundant near the coast and common west of the Cascades where it often dominates the forest shrub layer. Remnant stands occur among higher peaks of Great Basin mountain ranges. Oceanspray habitat varies considerably and includes streambanks, the understory of moist woods, cutover timberland and dry rocky soils and talus slopes. For a current distribution map, please consult the Plant Profile page for this species on the PLANTS Web site.
Also known as Holodiscus boursieri (Carr.) Rehd., Holodiscus microphyllus Rydb., Spiraea discolor Pursh, Sericotheca discolorRydb., and Schizonotus discolor Raf. Additional common names include creambush, arrowwood, ironwood, hardhack, rock spiraea and mountain spray.
Regularity: Regularly occurring
Regularity: Regularly occurring
Botanical description: This description covers characteristics that may be relevant to fire ecology and is not meant for identification. Keys for identification are available (for example, [97,99,117,193]). Morris and others  provide a key for identifying creambush oceanspray and other shrubs in winter. Creambush oceanspray and rockspirea are distinguished by their forms, leaf characteristics, and distributions ; intergradation of the 2 species is most pronounced in Nevada  and Utah .
Form: Creambush oceanspray is a deciduous [1,41,198], spreading shrub with slender arching branches [75,136,223]. It can range from bushy forms about 2.5 feet (0.75 m) tall on poor or frequently disturbed sites to arborescent forms that may be 20 feet (6.1 m) tall in coastal areas. Plants are usually 3 to 10 feet (1-3 m) in height [52,99,198]. They typically have multiple branches . Stem wood is hard and dense ; bark of mature plants is shreddy [41,174]. Stand structures of plant communities where creambush oceanspray is important are discussed in the Stand structure section of Fuels.
Leaves and flowers: The leaves are mostly 1.6 to 2.75 inches (4-7 cm) long and 0.8 to 2.75 inches (2-7 cm) wide [136,223]. Creambush oceanspray has a large leaf area relative to most associated shrubs. In the Siskiyou Mountains of southwestern Oregon, its leaves were more densely packed, larger, thinner, and more prone to wilt than leaves of associated shrub species .
Creambush oceanspray flowers are small, about 2 mm long . They are borne on large, showy, terminal panicles that may reach 12 inches (30 cm) long . The name "oceanspray" is derived from these masses of loose, creamy plumes . The fruit is a 1-seeded  achene [41,97,117], about 2 mm long .
Roots: Rooting depth is likely associated with depth to bedrock. In southwestern Oregon, creambush oceanspray extracted water from no deeper than 3 feet (1 m) below ground, indicating a shallow root system . Dyrness and Franklin  had similar findings in the west-central portion of the Cascade Range in Oregon, where shallow soils confined roots to <3 feet below the soil surface. However, a planting guide for the Pacific Northwest reports creambush oceanspray roots as "deep and wide" , and researchers described creambush oceanspray as "relatively deep-rooted" in the Blue Mountains .
Descriptions of creambush oceanspray's root morphology were not found in the literature as of 2010.
Physiology: Creambush oceanspray is highly drought tolerant . It has adapted to dry sites and drought by shutting down or slowing its rate of transpiration. In droughty conditions, it apparently uses water less efficiently than associated sclerophyllous species. Its large leaf area, however, may partially compensate for low water transpiration rates in summer. It is likely that creambush oceanspray depletes water in upper soil layers rapidly in summer .
Antieau  suggested that creambush oceanspray may differ in water-use efficiency and cold tolerance across its distribution.
Catalog Number: US 1785473
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Preparation: Pressed specimen
Collector(s): I. W. Clokey
Year Collected: 1938
Locality: Griffith's Mine, Clark, Nevada, United States, North America
Elevation (m): 2450 to 2450
- Isotype: Ley, F. A. 1943. Bull. Torrey Bot. Club. 70: 283.
Catalog Number: US 2308256
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Preparation: Pressed specimen
Collector(s): H. Park & S. Parks
Year Collected: 1937
Locality: Darlingtonia, Smith River., Del Norte, California, United States, North America
Elevation (m): 137 to 137
- Possible isotype: Ley, F. A. 1943. Bull. Torrey Bot. Club. 70: 280.
Soils: Creambush oceanspray tolerates soils with a pH range from approximately 5.0 to 7.5, fine to coarse textures, and low nutrient and moisture content . In western redcedar-western hemlock forests of northern Idaho, it had significantly greater cover in soils with pH above 6.1 than in soils with lower pH values (6% vs. ≤1% cover, P=0.05) . Soils supporting creambush oceanspray are often shallow ([87,94,100], review by ). In the Blue Mountains of Washington and Oregon, however, creambush oceanspray is dominant in Pacific ponderosa pine-Rocky Mountain Douglas-fir forests on deep, fertile soils similar to those of Palouse prairie .
Creambush oceanspray is common in sands and clay loams (review by ) but may occur in all soil textures. In the Cascade Range of Oregon, coast Douglas-fir/creambush oceanspray communities occur on coarse soils and loams but not on fine soils . A study in the Blue Mountains, however, found creambush oceanspray presence was positively correlated with fine-textured soils (P<0.05) . In western redcedar-western hemlock forests of northern Idaho, creambush oceanspray cover, frequency, and importance value increased as soil organic matter increased; increases in importance values were significant (P=0.05) . Soils supporting creambush oceanspray are often stony [67,87,94,97,98,100], and creambush oceanspray sometimes grows within rock crevices. It is common on talus slopes (review by ). In Nevada and western Utah, creambush oceanspray grew on talus slopes near mountain meadows and in granite boulder piles .
|Creambush oceanspray occurs on a variety of parent materials. In the Cascade Range of Oregon, coast Douglas-fir/creambush oceanspray communities occur on poorly developed basalts, andesites, and other parent materials of volcanic origin . At Oregon Caves National Monument, mixed-conifer forests with creambush oceanspray occur on soils of diorite origin . Poison-oak (Toxicodendron diversilobum)-creambush oceanspray-Mexican elderberry (Sambucus mexicana) communities of San Luis Obispo County, California, are associated with andesite-derived soils .||Photo © Br. Alfred Brousseau, St Mary's College|
Moisture regime: Creambush oceanspray is most common on dry sites. McDonald and others  list creambush oceanspray as an indicator species of dry montane/shrub forests of the Northern Rocky Mountains. Creambush oceanspray is also associated with dry montane forests in British Columbia [168,179] and elsewhere in the Pacific Northwest. It is an indicator species of very dry to moderately dry, nitrogen-medium soils in coastal British Columbia [110,111]; its occurrence decreases with increasing precipitation . It also grows in dry to fresh soils in coniferous forests of interior British Columbia . The western hemlock-coast Douglas-fir/creambush oceanspray association occurs on some of the hottest and driest sites in the Cascade Range of Washington . In the west-central portion of the Cascade Range in Oregon, Dyrness and Franklin  found the coast Douglas-fir/creambush oceanspray association occurs on the dry end of coast Douglas-fir forest types. In an extreme case, creambush oceanspray is "widespread but not abundant" on the Indian Plateau of southwestern Oregon. The plateau is a severe site known for widely fluctuating and extreme temperatures in winter and summer and a record of poor artificial regeneration of conifers .
Creambush oceanspray is also reported from sites with moist to mesic soils. It is frequently associated with riparian communities (review by ). In southeastern Washington and northern Idaho, Pacific ponderosa pine/mallow ninebark-creambush oceanspray communities dry out later in the growing season than Pacific ponderosa pine/common snowberry communities . Creambush oceanspray occurs on moist woodland edges in California  and in moist open woods in British Columbia . In western redcedar-western hemlock forests of northern Idaho, creambush oceanspray frequency was significantly greater on sites with 21% to 25% soil moisture content than on sites with drier or wetter soils .
Aspect and topography: This species is most common on warm, dry, south-facing slopes [67,98,165]. A grand fir/creambush oceanspray association in southwestern Washington is common on exposed, south-facing slopes and on ridgetops. Sites having this association remain snow-free much of the year and experience extreme summer drought . In Douglas-fir (Pseudotsuga menziesii) forests in the Columbia River Gorge of Washington, creambush oceanspray had greatest cover on south-facing slopes (13%) and least cover in mesic ravines (6%) . The coast Douglas-fir/creambush oceanspray association in Oregon's Coast Ranges occurs most often on relatively steep, south- or west-facing slopes between 2,000 and 3,000 feet (600-900 m) elevation. The environment is hot and dry, and the growing season is long, with drought developing by midsummer. Snowpacks are not generally deep or persistent . The western hemlock-Douglas-fir/creambush oceanspray association is found in some of the hottest and driest forests in the western Cascade Range. Sites are "always" upper slopes and fairly steep, and drainage and solar input are "excessive" . Coast Douglas-fir/creambush oceanspray communities in the Cascade Range of Oregon are also most prevalent on dry, south-facing slopes . In western redcedar-western hemlock forests of northern Idaho, creambush oceanspray cover, frequency, and importance values were significantly greater on south- than north-facing slopes (P=0.05) .
Creambush oceanspray grows on more mesic exposures as well. In montane zones on the Umatilla National Forest, it dominated the understory on north, northeast, northwest, and east aspects ; in western Oregon clearcuts it occurred only on north-facing slopes . Creambush oceanspray mostly grows on moist slopes in southern California , where it reaches the southern end of its distribution.
Elevation: Creambush oceanspray occurs from sea level to about 7,000 feet (2,150 m) across its range. It mostly grows on low-elevation montane sites. In western redcedar-western hemlock forests of northern Idaho, creambush oceanspray cover, frequency, and importance values were significantly greater on 3,000- to 3,400-foot (910-1,000 m) elevations than on higher-elevation sites (P=0.05) . Creambush oceanspray grows mostly on high peaks in the Great Basin (review by ).
|eastern Washington and Oregon, Blue Mountains||1,700-4,800 feet |
|Deschutes National Forest, Oregon, east slopes||>2,800 feet, from ponderosa pine to subalpine mixed-conifer zones |
|California||<5,900 feet |
|southern California||<4,500 feet |
|Nevada||4,500-9,500 feet |
|Pacific Northwest||sea level to 5,500 feet |
Climate: Creambush oceanspray occurs mostly in dry zones , although it is characterized as a "predominantly humid zone species" in western Washington . Annual precipitation across its United States distribution [37,56,97,137,215,241] ranges from 9.3 inches (236 mm) in central Oregon  to 57 inches (1,140 mm) in western Washington .
Key Plant Community Associations
Creambush oceanspray is important or dominant in many plant communities of the Pacific Northwest, California, and the Northern Rocky Mountains. These communities include seral and old-growth conifer, seral and old-growth hardwood, mixed-riparian, and mixed-shrubland types.
Creambush oceanspray is called "the most widespread and possibly the most abundant flowering shrub" in coniferous forests of northeastern Washington and northern Idaho . On the Umatilla National Forest, Washington, it is dominant in coast Douglas-fir (Pseudotsuga menziesii var. menziesii), grand fir (Abies grandis), and western larch (Larix occidentalis) forests .
|In Oregon, coast Douglas-fir/creambush oceanspray associations on the Willamette National Forest are primarily structurally diverse old-growth stands, containing long-lived canopy trees and a subcanopy of younger trees. Most of the stands are >150 years old . Creambush oceanspray |
is common to dominant in dry white fir (A. concolor) forests in the Siskiyou Mountains of southwestern Oregon , and it is an important shrub
in Port-Orford-cedar (Chamaecyparis lawsoniana) communities of southwestern Oregon and northwestern California . It is important in many
mixed-conifer forests of southern Oregon and California [33,34]. These communities are codominated by Pacific ponderosa pine (P. ponderosa var.
ponderosa), coast Douglas-fir, Jeffrey pine (P. jeffreyi), California black oak (Quercus kelloggii), tanoak
(Lithocarpus densiflorus), and/or canyon live oak (Q. chrysolepis) . Creambush oceanspray is also important in knobcone pine
(P. attenuata) communities of southern Oregon and California .
|Creambush oceanspray in mixed-conifer forest of Oregon's Cascade Range. Photo permission of Craig Smith.|
In California, creambush oceanspray is a characteristic to dominant species of redwood (Sequoia sempervirens) [202,254], Pacific ponderosa pine , shore pine (P. contorta var. contorta) , and Sierra Nevada lodgepole pine (P. c. var. murrayana)  forests. It is a minor species in pinyon-juniper (Pinus-Juniperus spp.) communities .
Creambush oceanspray is associated with Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) and Rocky Mountain lodgepole pine (Pinus contorta var. latifolia) in northern Idaho ; it is commonly dominant in Rocky Mountain Douglas-fir forests of northern Idaho and Montana [178,217,225]. It is infrequent to common in western redcedar-western hemlock (Tsuga heterophylla-Thuja plicata)) forests of the Interior Pacific Northwest and the Northern Rocky Mountains [148,186].
Creambush oceanspray occurs in the understories of Oregon white oak (Q. garryana) communities throughout Oregon white oak's range ([147,185,216], review by ). It also occurs or dominates in other montane oak (Quercus spp.) communities in California .
Creambush oceanspray occurs in riparian communities throughout its range (review by ). Overstory dominants may be conifers, hardwoods or a mix [112,219]. Meriwether Lewis made the first scientific collection of creambush oceanspray on the banks of the Clearwater River in Idaho . Creambush oceanspray is dominant in grand fir floodplain associations of eastern Washington . In western hemlock stands in the central Cascade Range of Washington, it was more common on high floodplains than on low floodplains . On Myrtle Island Research Natural Area, Oregon, creambush oceanspray is occasional in red alder-Oregon ash (Alnus rubra-Fraxinus latifolia) and willow/field horsetail (Salix spp./Equisetum arvense) riparian communities .
Creambush oceanspray is common to dominant in mixed montane shrublands of the Pacific Northwest and the Northern Rocky Mountains [51,204]. These communities are common on harsh slopes and in coniferous forests in early succession . In montane regions of Nevada and western Utah, creambush
oceanspray occurs in mosaics of mountain meadow and mountain big sagebrush (Artemisia tridentata subsp. vaseyana) stands . In Redwood National Park, California, it occurs in Lewis' mockorange/brittle bladderfern (Philadelphus lewisii/Cystopteris fragilis) and Sierra gooseberry/varileaf phacelia (Ribes roezlii/Phacelia heterophylla) bald-hill communities . On the Jasper Ridge Biological Reserve in coastal northern California, creambush oceanspray is an associated species in chamise (Adenostoma fasciculatum) chaparral communities .
Publications describing plant communities where creambush oceanspray is a dominant or indicator species are listed below.
- western hemlock/salal (Gaultheria shallon)-oceanspray forest association of the Olympic National Forest 
- western hemlock-coast Douglas-fir/creambush oceanspray association of the Gifford Pinchot National Forest 
- coast Douglas-fir-Pacific madrone (Arbutus menziesii)/hairy honeysuckle (Lonicera hirsuta)-creambush oceanspray and
coast Douglas-fir-Pacific madrone/salal-creambush oceanspray associations across the Puget Trough of west-central Washington 
- Rocky Mountain lodgepole pine/Rocky Mountain maple-Saskatoon serviceberry (Acer glabrum-Amelanchier alnifolia)-creambush oceanspray woodlands and forests;
occur on the east side of the Cascade Range, the Okanogan Highlands, and the Blue Mountains 
- Pacific ponderosa pine-coast Douglas-fir/Saskatoon serviceberry-creambush oceanspray communities of the Blue Mountains 
- creambush oceanspray and creambush oceanspray-mallow ninebark shrublands on north-facing slopes of the Blue Mountains 
- east-canyon mixed shrublands of the Columbia Basin and Blue Mountains 
- grand fir-creambush oceanspray floodplain association of eastern Washington; this type is a variant of the grand-fir-common snowberry (Symphoricarpos albus) floodplain association 
- Rocky Mountain Douglas-fir-Pacific ponderosa pine-Rocky Mountain lodgepole pine/mixed shrub forest zone in the Wallowa Mountains 
- Pacific ponderosa pine/mallow ninebark (Physocarpus malvaceus)-creambush oceanspray association of southeastern Washington 
- Rocky Mountain Douglas-fir-mallow ninebark-creambush oceanspray habitat type of eastern Washington
- coast Douglas-fir/creambush oceanspray forest communities in the west-central Cascade Range; characterized by open stands of old growth 
- coast Douglas-fir/creambush oceanspray/grass and coast Douglas-fir/creambush oceanspray/vine maple (Acer circinatum) community types of the western
Cascade Range; the former is the most widely distributed of Oregon's dry-forest types 
- Rocky Mountain lodgepole pine/Rocky Mountain maple-Saskatoon serviceberry-creambush oceanspray woodlands and forests; occur on the east side of the Cascade Range
and the Blue Mountains 
- creambush oceanspray and creambush oceanspray-mallow ninebark shrublands on north-facing slopes of the Blue Mountains 
- Pacific ponderosa pine-Rocky Mountain Douglas-fir/western snowberry-creambush oceanspray communities of the Blue Mountains 
- east-canyon mixed shrublands of the Columbia Basin and Blue Mountains 
- westside Oregon white oak/creambush oceanspray and dry coast Douglas-fir/creambush oceanspray woodlands and forests; mostly in Willamette Valley and the
Klamath Mountains 
- coast Douglas-fir/creambush oceanspray-whipplevine (Whipplea modesta) series on the Coast Ranges; occurs on the Medford District of BLM and on the
Siskiyou and Rogue River National Forests. Indicative of dry sites .
- coast Douglas-fir/creambush oceanspray/salal habitat type off the southern coast 
- coast live oak (Q. agrifolia)/creambush oceanspray-common snowberry subseries of California's hardwood rangeland cover types; on upper-elevation
(>1,250 feet (380 m)), mesic sites 
- redwood-coast Douglas-fir-hardwood/creambush oceanspray vegetation types of the North Coast Ranges 
- canyon live oak (Q. chrysolepis)-creambush oceanspray forest cover type of central California 
- Rocky Mountain Douglas-fir/mallow ninebark-creambush oceanspray habitat type [51,152]
- Pacific ponderosa pine/mallow ninebark-creambush oceanspray association
- Rocky Mountain Douglas-fir/creambush oceanspray and Rocky Mountain Douglas-fir/mallow ninebark-creambush oceanspray forest habitat types 
- climax western redcedar-western hemlock, Rocky Mountain Douglas-fir, grand fir, and subalpine fir (A. lasiocarpa)-Rocky Mountain Douglas-fir-grand
fir forests 
- indicator species of the Rocky Mountain Douglas-fir/mallow ninebark habitat type 
- indicator species of dry western redcedar-western hemlock/shrub, Pacific ponderosa pine/shrub, and Rocky Mountain Douglas-fir/shrub forests 
Oceanspray is typically propagated by seed requiring 15 to 18 weeks of cold moist storage (stratification) to overcome dormancy. There are more than 5,000,000 seeds per pound. Seed viability is reported as less than 10%. Seedlings develop slowly. Oceanspray can also be propagated from softwood or hardwood cuttings or by layering. Success in rooting varies widely depending on clone and technique. Softwood cuttings taken in spring may be treated with a rooting hormone and grown under mist with bottom heat. Better results may be expected with fall or winter collected hardwood cuttings, also treated with rooting hormone. Autumn is the best time to transplant container stock.
Creambush oceanspray is most frequent on south slopes of dry montane forests (see Site Characteristics); these sites typically burn earlier in the season or with higher severities than cooler, drier sites. In northern Idaho, Smith and Fischer  placed the Pacific ponderosa pine, Rocky Mountain Douglas-fir, and grand fir forests where creambush oceanspray is most typically dominant in Fire Group 2. These forests tend to have warm temperature regimes, dry to moderate soil moisture, and are generally more productive—with heavier loads of downed woody fuels—compared to cooler or drier forests. Creambush oceanspray also occurs in mesic to moist grand fir forests (Fire Group 7); these forests also have heavy fuel loads. See Smith and Fischer  for fuel load measurements representative of coniferous forest habitat types where creambush oceanspray is important in northern Idaho.
In Pacific ponderosa pine-grand fir forests of Washington and Oregon, growing-season moisture content of shrubs, including creambush oceanspray, averaged >125% over 2 years. Shrub moisture content peaked in June at ~175%. Moisture contents of dominant overstory trees are also described in this study .
In many forest types with creambush oceanspray, fire exclusion has resulted in higher loads of woody debris compared to woody fuel loads when historic FIRE REGIMES were still functioning. In white fir stands in the Siskiyou Mountains of southwestern Oregon, large woody-debris loads were positively correlated with time-since-fire (P=0.01). Snag density was positively correlated with low (30 snags/ha) and high (23 snags/ha) fire severities (P=0.05). The authors attributed the correlation to nonconsumption of preexisting snags at low fire severity and creation of new snags at high severity. In this study, creambush oceanspray dominated the shrub layer of white fir stands in dry, interior valleys .
Stand structure: Stand structure of communities where creambush oceanspray is an important component of the vegetation is variable, as is the amount of fuel creambush oceanspray contributes. On some sites, structure is open, with a sparse shrub component. In the west-central portion of the Cascade Range of Oregon, the coast Douglas-fir/creambush oceanspray association displayed a relatively open stand structure (30-60% crown closure) of old growth, with few shrubs and a "very poorly developed" herb layer. Creambush oceanspray cover averaged 5% . Another study of coast Douglas-fir/creambush oceanspray communities in the Cascade Range found that except for creambush oceanspray, the tall-shrub layer was depauperate; low-shrub and herbaceous cover was also low. Incense-cedar, however, was encroaching in the subcanopy. Tree densities averaged 53 stems/ha for coast Douglas-fir and 5/ha for incense-cedar . Live shrubs, including creambush oceanspray as a dominant, comprised <5% of total stand biomass in mixed-conifer communities in the White Cap Wilderness Study Area of northern Idaho. Total shrub fuel loads ranged from 204 to 2,190 lbs/acre; shrubs were 0.6 inch to 27 inches (1.5-69 cm) tall, with 2% to 50% cover .
Some communities with creambush oceanspray have denser overstories and/or understories. A coast Douglas-fir/creambush oceanspray stand on the west-central portion of the Cascade Range, Oregon, had 70% tree cover, 46% shrub cover, and 36% herb cover. Aspect of the forest was southwest; it was the hottest and driest of 18 stand types examined . Bailey  found coast Douglas-fir/creambush oceanspray-salal habitat types off the southern coast of Oregon had relatively open canopies and "well-developed" shrub layers. Creambush oceanspray averaged 30% cover . Western redcedar-western hemlock forests often have a dense overstory, but understory cover of creambush oceanspray and other shrubs may be sparse .
Mixed-conifer forests of southern Oregon and California are structurally and compositionally complex, with small conifers—often white fir and/or incense-cedar—often forming ladder fuels in a well-developed subcanopy. Snags and large, downed woody debris are common, but fuel loads are highly variable. Many of these mixed-conifer forests support a moderate to dense shrub understory, although some have few shrubs but a dominant herbaceous layer, and others have both depauperate understory and ground layers . Stand structure in California's mixed-conifer forests was mostly open in the presettlement period .
Insect attacks increase snag densities in creambush oceanspray habitats, which eventually increase dead and downed woody fuel loads. Youngblood and Wickman  provide data on stand structure, live and dead tree abundance, and shrub and herb cover of a grand fir-Douglas-fir forest attacked by Douglas-fir tussock moths 23 years prior. Creambush oceanspray was an important component of the understory (5% cover); the site was in the Wenaha-Tucannon Wilderness in the Blue Mountains of Washington and Oregon .
Models: A few models were available for predicting creambush oceanspray's contribution to total fuel loads as of 2010. Smith and Brand  review equations for predicting creambush oceanspray biomass. Harris  presents models to predict creambush oceanspray aboveground biomass and cover; the models were developed from data collected in coast Douglas-fir, grand fir, and western larch forests on the Umatilla National Forest. Brown  provides a model for predicting total aboveground creambush oceanspray biomass and total leaf biomass based on basal stem diameter. Samples on which the model is based were collected in northern Idaho and western Montana .
Leaf area indices are used in some fuel models . In the Siskiyou Mountains of southwestern Oregon, creambush oceanspray had a large mean leaf area compared to associated shrubs; about twice as large as the leaf areas of associated greenleaf manzanita (Arctostaphylos patula) and redstem ceanothus (Ceanothus sanguineus) . Agee and Lolley  placed creambush oceanspray in fuel type 2: shrubs with thick stems but thin leaves.
More info for the terms: climax, codominant, cover, frequency, mesic, prescribed fire, shrub, shrubs, succession, tree, tussock
Creambush oceanspray is most common in early succession but occurs in all stages of succession. In mesic coniferous forests of northwestern Montana, it is approximately 5 times as dense in stands ≤150 years old than in old growth .
Seral occurrence: Disturbance favors creambush oceanspray [111,113]. Kruckeberg  characterized creambush oceanspray as a "colorful reclaimer of open or disturbed lands" of the Pacific Northwest, where it commonly establishes on recently logged sites, in second growth, and on roadbanks. It is especially common in seral Douglas-fir forests . Following the Sundance Fire in northern Idaho, creambush oceanspray was important or codominant in the first decade of postfire succession in Rocky Mountain Douglas-fir-western hemlock forests . On another site in northern Idaho, creambush oceanspray grew rapidly and dominated early-seral sites after a Rocky Mountain Douglas-fir forest was clearcut. The shrub layer regained precutting cover about 60 to 80 years after tree harvest . Creambush oceanspray seedlings established 3 growing seasons after a debris flow on the Central Coast Ranges of southwestern Oregon .
Creambush oceanspray prefers open sites [111,218]. It is described as a "light demanding, early successional" species . Logging and fire promote creambush oceanspray by opening the canopy. A study at the Eastern Oregon Experiment Station showed shrub cover, including that of creambush oceanspray, decreased with increasing cover of the mixed-conifer overstory. At about 90% canopy closure, shrub cover dropped to about 5%. However, even under a nearly closed canopy, a few shrubs remained alive in the understory, and seedlings of these shrubs established in canopy breaks . In coast Douglas-fir/salal stands on foothills of the Cascade Range, Washington, maximum creambush oceanspray cover occurred approximately 20 years after disturbance (clearcutting or wildfire); creambush oceanspray generally declined after that :
|Creambush oceanspray cover in different-aged Douglas-fir stands in Washington |
|Disturbance and stand age||Postclearcut year 5||Postfire year 22||Postfire year 30||Postfire year 42||Postfire year 73|
Defoliation and/or death of overstory trees due to insects may favor creambush oceanspray. In the Blue Mountains, creambush oceanspray showed 5% cover and 15% frequency 23 years after a record-breaking, 2-year attack by Douglas-fir tussock moths. About 1,250 miles² (3,240 km²) of a grand fir-Douglas-fir forest was affected by the outbreak .
Where it is a minor species, creambush oceanspray may not decline with canopy closure. In western redcedar-western hemlock forests of northern Idaho, its cover, frequency, and importance values were not significantly different in 5 canopy-cover classes ranging from 1% to 100% closure. Creambush oceanspray had ≤1% cover in all canopy-cover classes. Similarly, its cover, frequency, and importance values in these forests were not significantly different between logged, logged-and-burned, single-broadcast-burned, or multiple-broadcast-burned sites and sites with no history of logging or prescribed fire .
Logging: Lightly-shaded areas, such as those occurring a few decades after thinning, can promote creambush oceanspray growth . In Douglas fir-western hemlock forests of coastal Oregon, creambush oceanspray was associated with intermediate tree densities (P<=0.01) . In Douglas- fir stands in northern Idaho, its cover peaked about 20 years after logging .
|Creambush oceanspray cover in unlogged and logged Douglas-fir stands in northern Idaho |
|Treatment||Unlogged||Logged 13 years previous||Logged 20 years previous||Logged 40+ years previous|
On the Fort Lewis Military Reservation of Washington, a late 1990s study found creambush oceanspray cover was greater in a coast Douglas-fir/creambush oceanspray forest that had been clearcut in the 1920s and thinned twice afterwards (2.5% creambush oceanspray cover) than in a coast Douglas-fir/creambush oceanspray forest that had been partially cut only once, in the 1930s (1.5% creambush oceanspray cover) . In Pacific ponderosa pine and Rocky Mountain Douglas-fir habitat types of the Swan Valley, Montana, creambush oceanspray cover was greater on clearcut (15%) and plantation (10%) plots than on untreated plots (8%) .
In the Klamath Mountains of Oregon and California, shrubfields of creambush oceanspray and other sprouting shrubs develop after logging or fire when conifers fail to regenerate in the early postfire community; conifers eventually replace the shrubs on most sites .
Logging does not favor creambush oceanspray on all sites. In northern Idaho logging reduced creambush oceanspray frequency slightly compared to its frequency in the understory of an adjacent unlogged site. The study site was in a western hemlock/pachistima forest. A tall-shrub (>3 feet (1 m)) community developed after logging; creambush oceanspray was a component of this early-seral, tall-shrub community. On cut sites, creambush oceanspray had 1.4% frequency 7 years after logging and 0.7% frequency 25 years after logging. It had 2.1% cover on the unlogged site 25 years after treatments .
See Plant response to fire for more information on creambush oceanspray occurrence in seral postfire communities.Late-successional occurrence: Creambush oceanspray sometimes occurs in late succession. In Glacier Park's western redcedar-western hemlock forests, it is mostly restricted to late-seral or climax communities . Creambush oceanspray also occurs in late succession in western redcedar-western hemlock and grand fir forests of Montana , and it is a late-successional or climax species in some western hemlock habitat types of Washington  and northern Idaho . However, Henderson and others  point out that on the Olympic National Forest, climax western hemlock/salal-creambush oceanspray forests rarely develop due to recurrent fires. Coast Douglas-fir dominates the seral stands; creambush oceanspray often codominates the understory of these seral stands . Creambush oceanspray also dominates the understories of late-successional Douglas-fir forests in Oregon  and Montana . In mixed-conifer forests of western Oregon and California, creambush oceanspray and other deciduous shrubs are more likely to dominate in late succession on north-facing and other mesic slopes than on south-facing, dry slopes .
Creambush oceanspray has a soil seed bank [60,150]. In western hemlock forests of southwestern British Columbia, viable creambush oceanspray seed was more common in undisturbed soils (x=15.5 germinants/0.04-m² soil sample) compared to clearcut rights-of-way in early-seral succession (x=1-2.5 germinants/0.04-m² soil sample) .
Flower and seed production
Pollination and breeding system
Antieau  suggested that mountain ranges restrict creambush oceanspray breeding. A study across creambush oceanspray's distribution in Washington and Oregon showed phenotypic differences in creambush oceanspray (for example, in leaf area); these differences were related to geographic regions and climate .
Creambush oceanspray sprouts from the root crown after top-kill [55,60,61,140,140,150,167,209,228,245]. It may also reproduce by layering (, review by ).
Creambush oceanspray regenerates by sprouting from the root crown [55,60,61,140,140,167,209,228,245] and establishing from seed . Root crown sprouting is more prevalent than regeneration from seed [140,149,150,208,213]. Ackerly  characterizes creambush oceanspray's reproduction as "opportunistic regeneration following disturbance". Fire and other top-killing events favor creambush oceanspray regeneration.
Growth Form (according to Raunkiær Life-form classification)
More info for the term: phanerophyte
Raunkiaer  life form:
Fire Regime Table
Germination, seedling establishment, and plant growth
Fresh creambush oceanspray seed is dormant . In the field, it likely requires overwintering to germinate. As of 2010, little research had been conducted on creambush oceanspray's germination requirements . Stratification at around 41 oF (5 oC)  for 15 to 18 weeks breaks dormancy in the laboratory [12,113,197].
Creambush oceanspray seed may have low viability. According to a fact sheet, most seeds lack developed embryos, so only about 7% of a given seed lot may be sound .
Seedling establishment is uncommon [140,149,150,208,213] but has been documented a few times. Open stand structure , heat, and bare mineral soil may favor creambush oceanspray germination and establishment (review by ). In the Oregon Coast Range, creambush oceanspray seedlings emerged well (>70%) in both clearcuts and young, unthinned conifer stands; however, seedlings survived only in the young, unthinned stands . Creambush oceanspray established from seed 3 growing seasons after a debris flow on the Central Coast Ranges of southwestern Oregon . See Seedling establishment in the Plant Response to Fire section for studies on postfire seedling establishment.
A review states that creambush oceanspray seedlings grow slowly in their first 2 years of development . Plants released by overstory removal may grow rapidly, however. Daubenmire and Daubenmire  found that in northern Idaho, creambush oceanspray grew up to 15 feet (4.6 m) tall following harvest of the Rocky Mountain Douglas-fir overstory; this was twice its stature in unharvested Rocky Mountain Douglas-fir forests.
Life History and Behavior
More info for the terms: phenology, shrubs
Creambush oceanspray is among the first shrubs to initiate leaves in spring. Although floral buds swell in early  to late spring, creambush oceanspray is a late bloomer . Full flowering does not occur until late June or July and may continue into August in some areas [12,100]. Fruits mature in late summer and may persist until fall (reviews by [196,198]). Panicles and panicle branches typically persist through winter after drying in fall .
Leaf phenology is closely regulated by weather. In the Siskiyou Mountains of Oregon, leaf water conductance peaked in July . On the Jasper Ridge Biological Preserve, mean leaf age was 4.5 months; leaves were drought-deciduous and mostly absent by August . A study in the western redcedar-western hemlock zone of northern Idaho found summer or fall drought initiated leaf color change and leaf drop .
Creambush oceanspray consistently shows a late and long period of flowering throughout its distribution:
|Phenology of creambush oceanspray across its range|
|southern California||flowers June-August |
|northern Idaho||buds swell and burst late March-early April; |
leaf-out late March-mid-April ;
stem elongation late March-late June [55,170];
flowers early May-late June;
fruits late June-August [55,174];
leaves change color late June-late September [55,170];
leaves fall late July-late November;
seeds disperse late August-late November 
|Montana||flowers late June-July |
|Nevada||flowers June-August |
|southwestern Oregon||flower buds expand in July; |
flowers and fruits July-August 
|Oregon and western Washington||flowers May-July; |
seeds disperse August-September (review by )
|Pacific Northwest||flowers midsummer |
|Puget Sound||flowers mid-June |
|Northern Rocky Mountains||flowers mid- to late July; |
fruit ripens late August;
seeds disperse late August-late November 
Molecular Biology and Genetics
Barcode data: Holodiscus discolor
Statistics of barcoding coverage: Holodiscus discolor
Public Records: 2
Specimens with Barcodes: 15
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: NNR - Unranked
Rounded National Status Rank: NNR - Unranked
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).
Pests and potential problems
The genus is largely free of insect pests and diseases although susceptibilities to fireblight (Erwinia amylovora), a fungal leaf spot (Septogloeum sp.) and aphids have been reported. It is also a host of the root parasite, pine broomrape (Orobanche pinorum).
From the Illustrated Flora of British Columbia, © Province of British Columbia
Creambush oceanspray may interfere with conifer seedlings on plantations . Because its roots are often shallow, creambush oceanspray is likely to compete with conifer seedlings for water .
Creambush oceanspray may decline with grazing despite its relative unpalatibility; its growth response in browsing and clipping studies has been mixed. In northern
Idaho sites with elk, moose, mule deer, and white-tailed deer, creambush oceanspray was more common inside than outside exclosures . Another northern Idaho study in
a Douglas-fir habitat type found creambush oceanspray decreased in cattle-grazed stands . Similarly, in the Bitterroot Mountains of northern Idaho, creambush oceanspray showed greater density, cover, and frequency on ungrazed plots than on plots grazed by cattle (989 vs. 522 plants/ha; 2.6% vs. 0.6%; 4.4% vs. 1.3%,
respectively, for desnity, cover, and frequency) . Garrison  recommends ≤50% to 60% utilization of creambush oceanspray to prevent the species' decline.
Daubenmire and Daubenmire  reported that in eastern Washington and northern Idaho, overgrazing of Pacific ponderosa pine/mallow ninebark stands, in which creambush oceanspray often codominates, may result in a disclimax ponderosa pine/bluegrass (Poa spp.) community.
Exclosure studies in eastern Washington and eastern Oregon found that creambush oceanspray production was significantly greater (P≤0.04) for completely clipped plants (100% of new growth removed, x=200 g/0.25 acre) compared with heavily (75%, x=151 g), moderately (50%, x=162 g), and slightly (25%, x=64 g) clipped plants. Much of the new growth was long twig and branch sprouts. Moderate or heavier clipping suppressed flower production. Results were averaged over 4 to 5 consecutive years of clipping .
Cultivars, improved and selected materials (and area of origin)
Oceanspray is available as seed, container stock or bare-root from west coast native plant nurseries. It is a popular ornamental in parts of Europe where the cultivar ‘carneus’ may be available. A more compact growing related species, Holodiscus dumosus, native to the east side of the Cascade and Sierra Nevada mountains is sometimes called dwarf oceanspray. The Corvallis Plant Materials Center has two selected class germplasms pending release for western Washington and Oregon.
Oceanspray spreads slowly either by seed or by root sprouting although it will re-colonize rapidly following fire or other disturbance. It is non-toxic to humans and wildlife.
As a poor competitor, oceanspray benefits from weed control when young. The fibrous root system requires well drained soil at least 12 in. deep. Consider supplemental irrigation during establishment year or years with low rainfall. Cutting back mature stems will encourage vigorous growth suitable for cutting wood.
Relevance to Humans and Ecosystems
Value for rehabilitation of disturbed sites
Creambush oceanspray could potentially be used on Burned Area Recovery sites, although to date (2010), there was no documentation of its suvivorship after transplanting onto burns. It is used successfully for erosion control (, review by ), highway plantings, windbreaks, riparian plantings, and wildlife plantings (reviews by [196,197]). It establishes readily through natural regeneration on burned sites [35,246] (see Successional Status and Plant response to fire). In northern Idaho, for example, creambush oceanspray dominated (48% of total understory cover) a Pacific ponderosa pine-Rocky Mountain Douglas-fir stand in early postfire succession; its size (10-15 feet (3-4.6 m)) and relative unpalatability allowed it to compete successfully with other shrubs for light, moisture, and space. Because it is a "poor forage species", researchers predicted it would dominate the burn until crowded out by conifers .
Creambush oceanspray is propagated from cuttings or seed [12,113], with cuttings the usual method. A 2004 review found creambush oceanspray seeds were "rare and costly" , and as of 2008, there were no published guidelines for growing this species from seed . See these sources: (, reviews by [196,197]) for information on propagating creambush oceanspray. Plants are available commercially .
Importance to Livestock and Wildlife
Browse: Creambush oceanspray is a minor browse species [41,50,125,161,178,203,226]. Ungulates generally browse it only when more palatable forage is unavailable . Many low-elevation, dry-site Douglas-fir forests with creambush oceanspray are important cattle rangelands, but the cattle generally seek forage other than creambush oceanspray . Creambush oceanspray is considered poor forage in Idaho  and an undesirable "competitor" with redstem ceanothus, a more desirable browse species . Among ungulates in British Columbia, only Sitka black-tailed deer made much use of creambush oceanspray .
|Importance of creambush oceanspray as browse for wild ungulates in British Columbian |
|Ungulate||Importance as Browse|
|Sitka black-tailed deer||moderate|
|Rocky mountain elk||low|
However, because this species is common and readily available to wildlife and livestock on low-elevation rangelands, ungulates may make light but frequent use of creambush oceanspray in summer [161,226]. Cattle use it as summer forage in northern Idaho [35,217] and northeastern Oregon .
Wildlife [125,161] and livestock  sometimes browse creambush oceanspray more heavily [36,62,115], especially in late fall and winter when green forage is less available [125,197]. Snowshoe hares in the Flathead region of western Montana use the leaves and twigs for fall forage . Studies on the Bitterroot National Forest and in the Rattlesnake Creek drainage of western Montana found elk, mule deer, and white-tailed deer preferred creambush oceanspray as winter forage [109,146]. Columbian black-tailed deer in western Oregon browse creambush oceanspray twigs in winter ; mule deer on the Los Padres National Forest of southern California also use creambush oceanspray . Creambush oceanspray is heavily utilized by migrating mule deer and elk in central Washington .
Palatability and/or nutritional value: Creambush oceanspray is usually unpalatable to ungulates [157,158] and other browsing animals. A review rated its palatability as poor to fair for cattle and fair for domestic sheep . A study on the Tillamook Burn of northwestern Oregon found mountain beavers browsed creambush oceanspray less than expected based on availability . New postfire sprouts are most palatable ([18,166], review by ). On burned sites in northern Idaho, big game species in northern Idaho preferred browsing sprouts of creambush oceanspray and other shrubs to browsing current-year growth of shrubs on adjacent unburned sites, especially the first growing season after fire . On one site, elk utilization of creambush oceanspray increased from 1.3% before fire to 36.3% a year after prescribed fire; elk use dropped to 6.9% in postfire year 2 . Asherin  also noted that big game species browsed creambush oceanspray readily in postfire year 1, but use dropped after that. Browsing ungulates may pass over creambush oceanspray sprouts if more palatable shrubs are available. On a wildfire-burned Rocky Mountain Douglas-fir/mallow ninebark habitat type on upper Selway River, northern Idaho, mule deer browsed creambush oceanspray "minimally" in postfire years 2 and 3, while western serviceberry and Scouler willow were used heavily . Following prescribed fires on the Lochsa Watershed in northern Idaho, elk preferred Scouler willow, western serviceberry, and Rocky Mountain maple sprouts to those of creambush oceanspray .
Habitat: Conifer/creambush oceanspray communities provide important habitat to a variety of wildlife species. Along the Umatilla River of Oregon, white-tailed deer used Pacific ponderosa pine-coast Douglas-fir/creambush oceanspray and Pacific ponderosa pine/creambush oceanspray communities more than expected based on availability (P<0.0001) . On sky islands across Nevada and in western Utah, yellow-bellied marmot burrows were closely associated with creambush oceanspray, "almost without exception" [64,65]. In the central Oregon Coast Ranges, creambush oceanspray was found on streamside and upslope habitats where 18 of 22 small mammal species and 9 of 13 amphibian species known to the area were captured . This shrub is also common in northern Idaho Pacific treefrog habitats .
Cover value: Creambush oceanspray provides cover for a variety of species. Blue grouse hide beneath creambush oceanspray and other shrubs . Dense shrub understories in Rocky Mountain Douglas-fir/mallow ninebark habitat types—where creambush oceanspray is common to codominant—provide visual and thermal cover for deer and elk; in addition, these sites supply nesting habitat, cover, and food for a variety of nongame birds and mammals .
Other uses and values
Traditional uses: Native Americans used creambush oceanspray for making implements, as medicine , and sometimes as food. The long, straight, hard branchwood was highly prized for making arrow shafts [50,224], as well as digging sticks, fishing hooks, and needles [73,224]. Native Americans used creambush oceanspray for treating viral and skin diseases (, review by ) and as a tonic . The bark and leaves were dried and pulverized for application to burns or sores . The Pima made tea from the leaves , and Native Americans in the Inland Northwest ate the seeds .
This hardy species, tolerant of wide moisture regimes, soil types, and both sun and shade, is useful for low maintenance riparian plantings, reclamation of droughty and rocky or disturbed sites, and windbreaks. This broad adaptation and abundant mid-summer flower clusters at the tips of arching branches make oceanspray a popular ornamental for highway and landscape plantings and an important host for beneficial insects. Palatability for livestock and wildlife is generally considered to be low but varies with climate and incidence of fire. It is browsed by cattle, deer, elk, snowshoe hares and dusky-footed wood rats but not moose. As a common understory species, oceanspray provides cover for numerous birds and small mammals and also treefrogs. Seeds were eaten by Native Americans who also used the hard straight stems for arrow, spear and harpoon shafts, halibut hooks, digging sticks and sewing and knitting needles. Pioneers used the wood as pegs in place of nails. Medicinally, an infusion of dried seed was used to treat diarrhea and prevent contagious diseases. A poultice of oceanspray bark and leaves was applied to burns or sores.
Holodiscus discolor, commonly known as ocean spray or oceanspray, creambush or ironwood, is a shrub of western North America. It is common in the Pacific Northwest where it is found in both openings and the forest understory at low to moderate elevations.
Holodiscus discolor is a fast-growing deciduous shrub growing to 5 m tall. Its alternate leaves are small, 5–9 cm long and 4–7 cm broad, lobed, juicy green when new. Cascading clusters of white flowers drooping from the branches give the plant its two common names. The flowers have a faint sweet, sugary scent. It bears a small, hairy fruit containing one seed which is light enough to be dispersed by wind.
Historically the plant has been used for many purposes. The Lummi used the flowers as an antidiarrheal and the leaves as a poultice. Many other tribes used the wood and bark for making tools and furniture. Noted for the strength of its wood, it was often used for making digging sticks, spears, arrows, bows, harpoons and nails. The wood, like with many other plants, was often hardened with fire and was then polished using horsetail. Several Native tribes, such as the Stl'atl'imx, would steep the berries in boiling water to use as a treatment for diarrhea, smallpox, chickenpox and as a blood tonic.
Holodiscus discolor, is found in a variety of habitats, from wet coastal forests to drier, cooler mountains further inland. It tends to grow in areas dominated by Douglas-fir. The plant is found in areas prone to wildfire, and it is often the first green shoot to spring up in an area recovering from a burn. It is commonly found in chaparral communities, which burn periodically. It also may grow in areas cleared by logging.
Holodiscus discolor is common in a variety of forest overstories. In the case of California black oak woodland, common understory associate species include western poison-oak, toyon and coastal wood fern.
- M. Casebeer (2004) Discover California Shrubs. Sonora, California: Hooker Press. ISBN 0-9665463-1-8
- "The Plant List: A Working List of All Plant Species".
- USDA Plants Profile (2008)
- "BSBI List 2007" (xls). Botanical Society of Britain and Ireland. Archived from the original on 2015-02-25. Retrieved 2014-10-17.
- Pojar, Jim; Andy MacKinnon (1994). Plants of the Pacific Northwest. Lone Pine Publishing. p. 71. ISBN 1-55105-042-0.
- Jepson Manual, 1993
- Pojar; J, MacKinnon, A.; Alaback, P., et al. 1956/1994. Plants of the Pacific Northwest Coast: Washington, Oregon, British Columbia & Alaska, ISBN 978-1-55105-530-5
- C. Michael Hogan (2008) California Black Oak Quercus kelloggii, Globaltwitcher.com, ed. Nicklas Stromberg
Names and Taxonomy
Holodiscus dumosus (Pursh) Maxim. var. glabrescens (Greenm.) Jeps. 
The Holodiscus taxonomy is confused because creambush oceanspray, rockspirea (H. dumosus),
and small-leaved rockspirea (H. microphyllus) are taxonomically and morphologically very similar [45,163]. Authorities separating these 3 closely related taxa do so based on different leaf morphologies [45,136] and distributions . This review follows the taxonomy of Lis (in ), who is authoring the Flora of North America's  Holodiscus chapter. In Lis's treatment, creambush oceanspray, rockspirea, and small-leaved rockspirea are treated as separate and distinct species . Some systematists lump either creambush oceanspray and rockspirea [104,236], creambush oceanspray and small-leaved rockspirea , or all 3 taxa  into single species.
creambush rock spirea
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