Philadelphus lewisii Pursh
mock-orange (Lewis' mock orange)
Hydrangeaceae (Hydrangea family)

Introduction to Vascular Plants


© Bob Thacker     (Photo ID #81114)


E-Flora BC Static Map

Distribution of Philadelphus lewisii
Click here to view the full interactive map and legend

Species Information

Deciduous shrub, erect, loosely branched, 1.5-3 m tall; bark reddish-brown, turning grey and flaking off in patches; twigs glabrous to hairy.
Opposite, short-stalked, widely egg-shaped to rounded, 3-5 cm long, margins entire to toothed, flat with 3 major veins from the leaf base, slightly sand-papery to touch.
Inflorescence of 3-15 flowers in a raceme; petals 4, white, 5-20 mm long, oblong; calyces top-shaped or bell-shaped, 4-6 mm long, 4-lobed, the lobes egg-shaped, 5-6 mm long; stamens yellow, numerous, unequal.
Capsules, 4-chambered, woody, 1 cm long; seeds many, spindle-shaped, brown, 2.5-3 mm long.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

Flower Colour:
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Summer to Fall
Source:  The USDA


Ecological Framework for Philadelphus lewisii

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
640 1 1540
Slope Gradient (%)
39 0 170

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

196 1 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 0 7
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

BG(18), CDF(29), ESSF(1), ICH(123), IDF(156), MS(4), PP(73)

Habitat and Range

Moist to dry talus slopes, shrublands, streamsides and open forests in the lowland, steppe and montane zones; frequent in S BC; E to SW AB and S to MT, ID and N CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Philadelphus gordonianus Lindl.
Philadelphus lewisii subsp. gordonianus (Lindl.) Munz
Philadelphus lewisii var. angustifolius (Rydb.) Hu
Philadelphus lewisii var. ellipticus Hu
Philadelphus lewisii var. gordonianus (Lindl.) Jeps.
Philadelphus lewisii var. helleri (Rydb.) Hu
Philadelphus lewisii var. intermedius (A. Nelson) Hu
Philadelphus lewisii var. oblongifolius Hu
Philadelphus lewisii var. parvifolius Hu
Philadelphus lewisii var. platyphyllus (Rydb.) Hu