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mountain spiraea, rose meadowsweet, rosy spiraea, shiny-leaf spiraea, subalpine spiraea, subalpine spirea

Douglas' spiraea, Douglas' spirea, Douglas' spirea (ssp. douglasii), hardhack, hardhack spirea, hardhack steeplebush, Menzies' spirea (ssp. menziesii), pink spirea, Reeve's spiraea or meadowsweet, rose spirea, spiraea

Habit Shrubs, 2–10 dm. Shrubs, 10–30 dm.
Stems

spreading to ascending, branched.

erect to ascending, branched.

Leaves

petiole 1–4 mm;

blade ovate to elliptic, 1–4 × 1–2(–3) cm, chartaceous, base usually obtuse, sometimes acute, margins crenate to serrate distally from middle, venation pinnate craspedodromous, secondary veins prominent, apex usually obtuse, sometimes acute, abaxial surface glabrous or puberulent, adaxial glabrous.

petiole 3–5 mm;

blade bicolorous, elliptic to obovate, 3–10 × 0.5–4 cm, chartaceous, base cuneate, margins serrate distally from middle, venation pinnate craspedodromous, secondary veins prominent, apex acute to obtuse, abaxial surface lanate to tomentose, glabrous, or pubescent, adaxial glabrous.

Inflorescences

mostly terminal, corymbiform or hemispheric panicles, 100–1000+-flowered, 2–4 × 2–4 cm height 0.8–1 times diam.;

branches glabrous or puberulent.

mostly terminal, conic panicles, [5–]8–25 × 3–6[–10] cm height 2–4 times diam. branches glabrous or glabrescent to tomentose.

Pedicels

1–3(–5) mm, glabrous or puberulent.

1–3 mm, glabrous or tomentose.

Flowers

2–4 mm diam.;

hypanthia hemispheric, 0.5–1.1 mm, abaxial surface glabrous or pubescent, adaxial pubescent;

sepals triangular, 0.8–1 mm;

petals light to dark pink, ovate to obovate, 1–2.5 mm, veins prominent;

staminodes 5–10, reduced, fused, appearing as scalloped ring;

stamens 35–40, 2 times petal length.

2–4 mm diam.;

hypanthia hemispheric, 1 mm, abaxial surface tomentose, adaxial glabrous;

sepals ovate, 1 mm;

petals light to dark pink, ovate to obovate, 1–2 mm;

staminodes 0;

stamens 25–35, 2–3 times petal length.

Follicles

oblanceoloid, 2–3 mm, shiny, glabrous, adaxial suture sparsely ciliate.

oblanceoloid, 2.5–3 mm, shiny, glabrous, adaxial suture sometimes ciliate.

Spiraea splendens

Spiraea douglasii

Distribution
map from FNA
CA; ID; MT; OR; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
map from FNA
AK; CA; CO; ID; MT; OR; WA; BC [Introduced in Europe]
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

The name Spiraea densiflora Nuttall ex Rydberg subsp. splendens (É. N. Baumann ex K. Koch) Abrams, which pertains here, is incorrect in relation to the priority of S. splendens (1875) over S. densiflora, which is an illegitimate name with no priority.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 3 (3 in the flora).

Spiraea douglasii has been popular in the garden trade and was used to develop a number of hybrids. In North America, the hybrid most likely to be encountered is S. ×billardii Hortus ex K. Koch, because the parental species are both native, although S. salicifolia was widely imported from Europe and thus S. ×pseudosalicifolia Silverside would also likely be encountered.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Parent taxa Rosaceae > subfam. Amygdaloideae > tribe Spiraeeae > Spiraea Rosaceae > subfam. Amygdaloideae > tribe Spiraeeae > Spiraea
Sibling taxa
S. alba, S. cantoniensis, S. chamaedryfolia, S. corymbosa, S. douglasii, S. japonica, S. lucida, S. prunifolia, S. salicifolia, S. stevenii, S. thunbergii, S. tomentosa, S. virginiana, S. ×hitchcockii, S. ×pyramidata, S. ×vanhouttei
S. alba, S. cantoniensis, S. chamaedryfolia, S. corymbosa, S. japonica, S. lucida, S. prunifolia, S. salicifolia, S. splendens, S. stevenii, S. thunbergii, S. tomentosa, S. virginiana, S. ×hitchcockii, S. ×pyramidata, S. ×vanhouttei
Subordinate taxa
S. splendens var. rosea, S. splendens var. splendens
S. douglasii var. douglasii, S. douglasii var. menziesii, S. douglasii var. roseata
Key
1. Young stems, leaf abaxial surfaces, and pedicels and bracteoles glabrous or glabrate.
var. splendens
1. Young stems, leaf abaxial surfaces, and pedicels and bracteoles puberulent.
var. rosea
1. Leaf abaxial surfaces lanate to tomentose.
var. douglasii
1. Leaf abaxial surfaces glabrous or pubescent
→ 2
2. Pedicels, hypanthia, and sepals tomentulose to sparsely pubescent.
var. menziesii
2. Pedicels, hypanthia, and sepals glabrescent or glabrous.
var. roseata
Name authority E. N. Baumann ex K. Koch: Monatsschr. Vereines Beförd. Gartenbaues Königl. Preuss. Staaten 18: 294. (1875) Hooker: Fl. Bor.-Amer. 1: 172. (1832)
Source FNA vol. 9, p. 405. Treatment author: Richard Lis. FNA vol. 9, p. 406. Treatment author: Richard Lis.
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