Willowleaf Meadowsweet

Foodplant / sap sucker
clustered Brachycaudus spiraeae sucks sap of live growing point of Spiraea salicifolia

In Great Britain and/or Ireland:
Foodplant / saprobe
solitary or gregarious apothecium of Godronia spiraeae is saprobic on dead stem of Spiraea salicifolia

Foodplant / parasite
Podosphaera clandestina parasitises Spiraea salicifolia

Foodplant / parasite
Podosphaera spiraeae parasitises Spiraea salicifolia

Shrubs erect, to 2 m tall. Branchlets dense, yellowish brown, slightly angled, pubescent when young, later glabrescent; buds ovoid to oblong-ovoid, 3–5 mm, with several brown scales, apex acute. Petiole 1–4 mm, glabrous; leaf blade oblong-lanceolate to lanceolate, 4–8 × 1–2.5 cm, glabrous, occasionally thinly pubescent on margin, base cuneate, margin entire to densely and sharply serrate or deeply incised doubly serrate, apex acute or acuminate. Panicles oblong to pyramidal, 6–13 × 3–5 mm, densely many flowered; rachis and pedicels thinly pubescent; pedicels 4–7 mm; bracts lanceolate to linear-lanceolate, 6–10 mm, slightly thinly pubescent, margin entire or with a few teeth. Flowers 5–7 mm in diam. Hypanthium campanulate, puberulous abaxially. Sepals triangular, 1–1.5 mm, ascending in fruit. Petals pink, ovate, 2–3.5 × 2–2.5(–3) mm, apex often obtuse. Stamens ca. 30, nearly 2 × as long as petals. Disk annular, with crenulate lobes. Carpels sparsely pubescent; styles shorter than stamens. Follicles erect, almost parallel, glabrous or sparsely pubescent on adaxial suture; styles recurved. Fl. Jun–Aug, fr. Aug–Sep.

Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Shanxi [Japan, Korea, Mongolia, Russia; Europe, North America].

River banks, meadows in valleys, damp grasslands, gullies, slopes, clearings; 200--900 m.

Spiraea salicifolia I,. Sp. PL 489. 1753
spiraea carpinifolia Wats. Dendr. pi. 66. 1823. Not S. carpimfolia Willd. 1809. Spiraea grandifiora I,odd. Bot. Cab. pi. 1988. 1833. Not S. grandiflora Sweet, 1830. Spiraea amena Raf. New Fl. 3 : 65. 1838.
A shrub, 1-2 m. high ; bark of the somewhat angled young twigs brown, finely puberulent, that of the old stems dark-gray ; petioles 2-6 mm. long, puberulent ; leaf-blades lance-oblong, broadest at the middle, acute at each end, sharply serrate, 3-7 cm. long, puberulent on the midrib and margins ; inflorescence a narrow panicle, 5-10 cm. long, 2-3 cm. wide, its branches puberulent ; hypanthium hemispheric, about 1 mm. deep, usually puberulent ; sepals ovate, acute ; petals pink, rounded-ovate, obtuse, about 2 mm. long ; follicles oblanceolate, glabrous, about 4 mm. long.
Type locality : Siberia.
Distribution : Native of Siberia and eastern Russia ; occasionally escaped from cultivation in the eastern states.

Spiraea salicifolia, the bridewort, willow-leaved meadowsweet, spice hardhack, or Aaron's beard, is a species of flowering plant in the family Rosaceae. A shrub, it is native to east-central Europe, Kazakhstan, all of Siberia, the Russian Far East, Mongolia, northern China, Korea, and Japan, and it has been widely introduced to the rest of Europe and to eastern North America. It has been cultivated since the 1500s for hedges and similar applications, but is not particularly well-behaved.