Spiraea prunifolia |
Spiraea corymbosa |
|
---|---|---|
bridal-wreath spiraea, bridalwreath meadowsweet, bridalwreath spirea |
dwarf spiraea, shinyleaf meadowsweet |
|
Habit | Shrubs, 10–30 dm. | Shrubs, 3–10(–15) dm. |
Stems | erect, virgate, branched. |
erect to arching, branched. |
Leaves | petiole 1–4 mm, pubescent; blade usually ovate to elliptic, sometimes oblanceolate, 1–4(–5) × 1–2 cm, membranous, base obtuse, margins serrulate, usually from near base to apex, sometimes only distally from middle, rarely nearly entire with few teeth apically, venation pinnate cladodromous, secondary veins not prominent, apex acute to obtuse, abaxial surface lanate to glabrescent, adaxial glabrate. |
petiole 3–8 mm, sparsely hairy; blade ovate to elliptic or suborbiculate, 2–10 × 1–2.5 cm, coriaceous, base obtuse, rounded, or subcordate, margins irregularly, coarsely and sharply doubly serrate from midpoint to apex, teeth acute and mucronate, number of primary and secondary serrations 1 times number of secondary veins (excluding inter-secondary veins), venation pinnate cladodromous, secondary veins not prominent, apex acute, obtuse, or rounded, abaxial surface mostly glabrous, adaxial glabrous. |
Inflorescences | mostly axillary, usually hemispheric panicles, sometimes simple fascicles, 3–6-flowered, sessile, 2–3 × 1–3 cm; bractlets 3–7 × 3–5 mm; branches pubescent. |
mostly terminal, corymbiform, 2–5 × 3–10 cm height 0.4–1.1 times diam.; branches rarely in axils of leaves, glabrous or glabrate. |
Pedicels | 10–30 mm, pubescent. |
1–3 mm, glabrous or glabrate. |
Flowers | 5–15 mm diam.; hypanthia campanulate, 1–1.2 mm, abaxial surface glabrous or sparsely hairy, adaxial glabrous; sepals ovate to ovate-triangular, 1–3 mm; petals white to cream, often with more than a single whorl of petals in most commonly escaped form, ovate to obovate, 2–10 mm; staminodes 10–16, irregularly fused; stamens 20–25, 0.5 times petal length. |
4–7 mm diam.; hypanthia hemispheric, 0.8–1 mm, abaxial surface glabrous or pubescent, adaxial glabrous; sepals triangular, 0.5–1 mm; petals chalky white to pink, orbiculate, 1.3–1.5 mm; staminodes 5–15 reduced to serrations; stamens 15–20, 2 times petal length. |
Follicles | oblanceoloid, 1.5–2 mm, glabrous, adaxial suture sparsely hairy. |
nearly fusiform, 2–3 mm, shiny, glabrous. |
2n | = 18. |
= 36. |
Spiraea prunifolia |
Spiraea corymbosa |
|
Phenology | Flowering Apr–Aug; fruiting May–Nov. | Flowering May–Oct; fruiting Jun–Nov. |
Habitat | Abandoned homesteads, roadsides, meadows, riparian zones | Open rocky soil, rocky, lightly wooded sites, dry or fast draining slopes, rocky edges of woods |
Elevation | 0–300 m (0–1000 ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; AR; CA; CT; DC; DE; GA; IL; KY; LA; MA; MD; MO; MS; NC; NJ; NY; OH; PA; TN; VA; WV; NS; ON; Asia (China, Japan, Korea) [Introduced in North America]
|
GA; MA; MD; NC; NJ; PA; TN; VA; WV; NS; ON [Introduced in e Europe] |
Discussion | Spiraea prunifolia is an ornamental shrub that can be found established in many areas. The double-flowered variant (most common in cultivation) may be assigned to var. prunifolia; single-flowered forms may be assigned to three other varieties [see Lu L. T. and C. Alexander (2003) for a key to native varieties in China]. L. H. Bailey et al. (1949), W. J. Bean (1970–1988, vol. 4), H. S. Maxwell and S. G. Knees (1989), A. Huxley et al. (1992, vol. 4), and references therein provide useful additional information on variation in S. prunifolia. M. De Cleene and J. De Ley (1981) noted that S. prunifolia and S. ×vanhouttei (see discussion below) are hosts to infectious hairy-root. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
H. A. Gleason and A. Cronquist (1963) and L. J. Uttal (1974) considered Spiraea corymbosa to be a variety of S. betulifolia. K. Sax (1936) found S. corymbosa to be a triploid with complete pollen sterility and hypothesized that it must exist as a diploid, or form viable egg cells, because it is involved in hybrids. If so, these cytological differences may be correlated with some morphological variation. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 408. | FNA vol. 9, p. 403. |
Parent taxa | Rosaceae > subfam. Amygdaloideae > tribe Spiraeeae > Spiraea | Rosaceae > subfam. Amygdaloideae > tribe Spiraeeae > Spiraea |
Sibling taxa | ||
Synonyms | S. betulifolia var. corymbosa, S. ostryfolia, S. repens, S. sororia | |
Name authority | Siebold & Zuccarini: Fl. Jap. 1: 131, plate 70. (1840) | Rafinesque: Précis Découv. Somiol., 36. (1814) |
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