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Taxon  Report  
Philadelphus lewisii  Pursh
Lewis' mock orange,   Mock orange,   Wild mock orange
Philadelphus lewisii is a shrub that is native to California, and also found elsewhere in western North America.
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Bloom Period
Genus: Philadelphus
Family: Hydrangeaceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Habitat: canyons, slopes

Communities: Yellow Pine Forest, Mixed Evergreen Forest, Foothill Woodland

Name Status:
Accepted by JEF + PLANTS

Alternate Names:
JEFPhiladelphus californicus
PLANTSPhiladelphus gordonianus
JEFPhiladelphus lewisii ssp. californicus
JEF + PLANTSPhiladelphus lewisii ssp. gordonianus
PLANTSPhiladelphus lewisii var. angustifolius
Information about  Philadelphus lewisii from other sources
Nursery availability from CNPLX
This plant is available commercially.
Jepson eFlora


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[Wikipedia] Description, Distribution & Habitat, Ecology, Human Use: Philadelphus lewisii, the Lewis' mock-orange, mock-orange, Gordon's mockorange, wild mockorange,[1] Indian arrowwood, or syringa,[2] is a deciduous shrub native to western North America, and is the state flower of Idaho.[2] It was first collected for science by scientist and explorer Meriwether Lewis in 1806 during the Lewis and Clark Expedition, and so was named after him.[3][4] Description The perennial shrub[5] is rounded and grows to 1.5?3 meters (4 ft 11 in ? 9 ft 10 in) in height. It sends out long stems which are red when new and fade to gray with age, the bark shredding in small flakes.[6] The oppositely arranged leaves vary in size across individual plants but they are usually oval, 3?5 centimeters (1+1?4?2 in) long, smooth or serrated along the edges, and light green in color with a rough texture.[6] The flowers are produced in clusters at the ends of long stems, with four white petals up to 4 cm (1+1?2 in) long and numerous yellow stamens. At the height of flowering, the plant is covered in a mass of blossoms. The flowers have a heavy, sweet scent similar to orange blossoms with a hint of pineapple.[6] The fruit is a small hard capsule about 1 cm long with woody, pointed wings, containing many brown seeds.[7] Drought will stunt fruit development and prevent the production of viable seeds.[8] The plant is somewhat similar in appearance to serviceberry.[9] Fruits Distribution and habitat Lewis' mock-orange occurs from northwestern California in the Sierra Nevada, north through the Pacific Northwest to southern British Columbia, and east to Idaho and Montana.[10] In the Cascades it occurs from sea level up to 7,000 feet (2,100 m), while in the Sierra Nevada it grows from 1,000?5,000 feet (300?1,520 m).[8] Though it is tolerant of moderate shade, it prefers full sun. It is common in open coniferous forests and on forest edges, and in drier regions of the Northwest it occurs mostly in wetter and riparian areas. It is also found in chaparral and seral communities.[8] It occurs on well-drained, moist sites, and is tolerant of rocky soil, and it is hardy from USDA zones 3 to 9.[7][8] Ecology Leaves and stems. The foliage of Lewis' mock orange is of moderate importance as winter forage for elk and deer in British Columbia, Idaho, and Montana. In Montana, a 1957 study found that it comprised 2% of mule deer diets in the winter and a trace in the summer.[8] The seeds are eaten by quail and squirrels.[8] It occurs in dense shrub habitats which provide good thermal and security cover for wildlife.[8] Philadelphus lewisii is able to spread vegetatively and from seed. It forms seedbanks in the top 2 inches (5.1 cm) of soil.[8] Fire ecology The shrub is native to relatively arid regions of the American West which experience frequent wildfires, and is therefore quite well adapted to fire. Although mock-orange is typically completely top-killed by fires, it will enthusiastically resprout from rhizomes and root crowns afterward.[8] A 1971 study found that in the next growing season after a fire, mock-orange had already regrown to 50% of its previous diameter and height, and that those plants had an average of 28.9 to 38.0 sprouts per plant postfire compared to just 0.6 to 1.5 before.[11] Lewis' mock orange palatability for Rocky Mountain elk is much greater after fire, with 36.3% of twigs browsed compared to only 1.3% on adjacent unburned sites.[8] Human use Ethnobotany Native American tribes used P. lewisii for numerous purposes. The hard wood was useful for making hunting and fishing tools, snowshoes, pipes, combs, cradles, netting shuttles, and furniture. The leaves and bark, which contain saponins, were mixed in water for use as a mild soap.[12]:?787? [1] The flowers were used in preparing perfumes and teas.[12]:?787? Cultivation Lewis' mock-orange prefers full sun to partial sun. It is drought-tolerant, will grow in poor soils, and is suitable for xeriscaping.[7] It provides a landscape with flashy flowers and a fruity scent. Waterton Mockorange Philadelphus lewisii 'Waterton' The Waterton Mockorange Philadelphus lewisii 'Waterton' was hybridized by the Alberta Horticultural Research Station in Brooks, Alberta, Canada. It grows to 4?6 ft. (1.2-1.8 m) in height. It is named for Augustus Griffin, who in 1933 noted that this plant was growing in what is now Waterton Lakes National Park in Canada.[7] Symbolism Philadelphus lewisii is the state flower of Idaho. The plant is protected by Idaho state law along with other native wildflowers and shrubs, and it is illegal to collect wild specimens on public property for export, sale, or transport without approval.[13] (contributed by Mary Ann Machi)

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2023. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 11/29/2023).