PHILADELPHACEAE

MOCK ORANGE FAMILY

Charles F. Quibell

Shrub, subshrub
Stem < 3 m, generally erect; bark generally peeling as thin sheets or narrow strips
Leaves simple, opposite, deciduous or not, ± hairy; stipules 0; blade ± round to narrowly elliptic, entire or toothed
Inflorescence: cyme, raceme, panicle, or flower 1, terminal or axillary, generally bracted
Flower bisexual, radial; sepals 4–7, free, spreading or erect; petals 4–7, free, ± round to narrowly elliptic, generally white; stamens 10–12 in 2 whorls or many and clustered, filament base linear or wide and flat; pistil 1, ovary superior to 2/3 inferior, chambers 2–8, ovules 1–2 or many per chamber, placentas axile or parietal, styles 3–8, free or fused at base
Fruit: capsule, loculicidal or septicidal; styles persistent or not
Seeds generally many, small to minute
Genera in family: 7 genera, 130 species: temp, subtropical n hemisphere; some cultivated for ornamental (Carpenteria, Deutzia, Philadelphus)
Recent taxonomic note: Recently treated within Hydrangeaceae [Soltis et al. 1995 Amer J Bot 82: 504–514]
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PHILADELPHUS

MOCK ORANGE

Shrub < 3 m
Stem: bark red-brown, aging gray, peeling as narrow strips or narrow rectangles; twigs glabrous to hairy
Leaves deciduous, petioled; blade 3-veined from base, ± glabrous to hairy, margin entire to toothed
Inflorescence: raceme, panicle, or flower one, terminal, ± open
Flower fragrant; sepals 4–5, glabrous to hairy; petals 4–5, white; stamens generally many, clustered, filaments linear, fused at base, ovary inferior to half-inferior, chambers 4–5, placentas axile, ovules many, style 1, branches generally 4 above middle, stigma linear along style branch
Fruit becoming woody, generally loculicidal
Seeds many, generally fusiform, generally brown
Species in genus: ± 65 species: temp Amer, Eurasia
Etymology: (Greek: for Ptolemy Philadelphus, Greek king of Egypt, 309–247 B.C.)
Reference: [Hu 1956 J Arnold Arbor 37:15–90]

Native

P. microphyllus A. Gray

LITTLELEAF MOCK ORANGE

Leaf: petiole 5–18 mm; blade 8–25 mm, 3–8 mm wide, narrowly ovate to elliptic, margin entire, ± rolled under
Inflorescence: flowers 1–3
Flower 1–1.5 cm wide; sepals 3–5 mm, petals 6–8 mm, widely elliptic
Ecology: Rocky slopes, cliffs
Elevation: 1200–2750 m.
Bioregional distribution: e Peninsular Ranges (San Jacinto Mountains, Santa Rosa Mtns), White and Inyo Mountains, e Desert Mountains
Distribution outside California: to Texas, n Mexico
Flowering time: May–Jul
Synonyms: subsp. stramineus (Rydb.) C.L. Hitchc
Plants with leaf blades 8–12 mm, rough-hairy above have been called subsp. pumilus (Rydb.) C.L. Hitchc
Reference: [Hitchcock 1943 Madroño 7:35–56]
Horticultural information: DRN, IRR: 1, 2, 3, 7, 10, 14, 15, 16, 18.