Spiraea tomentosa

Linnaeus

Sp. Pl. 1: 489. 1753.

Common names: Hardhack steeplebush spirée tomenteuse
EndemicIllustratedWeedy
Treatment appears in FNA Volume 9. Treatment on page 403. Mentioned on page 400, 132.

Shrubs, 3–15 dm. Stems erect to ascending, rarely branched. Leaves: petiole 2–3 mm; blade bicolorous, ovatelanceolate, 3–6 × 1–2.5 cm, coriaceous, base cuneate, margins coarsely serrate to crenate on distal 3/4, (secondary teeth on large and long-shoot leaves), venation pinnate craspedodromous, secondary-veins prominent, apex acute or rounded, abaxial surface densely white to gray, tan, or rusty, tomentose, adaxial glabrous or puberulent. Inflorescences predominantly terminal, narrow, conic panicles, 150–15,000+-flowered, 5–30 × 3–20 cm, branching varying from compact to wide and spreading; branches tomentose. Pedicels 0.1–1.5 mm, tomentose. Flowers 4–6 mm diam.; hypanthia hemispheric, 0.5–1 mm, abaxial surface tomentose, adaxial glabrous; sepals triangular, 0.7–1.1 mm; petals usually light to dark-pink, sometimes white or purple, ovate to orbiculate, 1–1.5 mm; staminodes 0; stamens 15–20, 1 times petal length. Follicles cymbiform, 2–2.5 mm, tomentose to arachnoid. 2n = 24, 36.

Distribution

V9 672-distribution-map.jpg

N.B., N.S., Ont., P.E.I., Que., Ala., Ark., Conn., Del., Ga., Ill., Ind., Kans., Ky., La., Maine, Mass., Md., Mich., Minn., Miss., Mo., N.C., N.H., N.J., N.Y., Ohio, Oreg., Pa., R.I., S.C., Tenn., Va., Vt., W.Va., Wis., in Europe

Discussion

Varieties 2 (2 in the flora).

P. J. Salamun (1951) conducted a comprehensive study of variation of the inflorescence across much of the range of Spiraea tomentosa and concluded that the two varieties could be segregated based upon the number of flowers or fruits per centimeter (density) of a lateral branch of the inflorescence. Intermediate populations have been identified, particularly in western New York and Pennsylvania. A. Gille (1949) discussed the overall distribution of S. tomentosa without evaluating varieties, and conducted a detailed study of its ecology in Quebec. The occurrences of this species in Oregon are as a weed in cranberry bogs; it has the potential to spread to natural wetlands. The species is reported as invasive in Belgium and Poland.

Selected References

None.

Key

1 Pedicels usually not visible, 0.1–0.5 mm; flowers or fruits 12–20 per cm of branches. Spiraea tomentosa var. tomentosa
1 Pedicels easily visible, 0.5–1.5 mm; flowers or fruits 6–11 per cm of branches. Spiraea tomentosa var. rosea
... more about "Spiraea tomentosa"
densely white +  and gray tan or rusty +
glabrous +  and puberulent +
rounded;acute +
Richard Lis +
Linnaeus +
reddish +  and dark-brown gray or gray-black +
not +  and exfoliating +
compound +  and simple +
opposite +  and alternate +
cuneate +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
ovatelanceolate +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
coriaceous +
1 cm10 mm <br />0.01 m <br /> (?) +  and 2.5 cm25 mm <br />0.025 m <br /> (?) +
glabrate +  and tomentose +
Hardhack +, steeplebush +  and spirée tomenteuse +
N.B. +, N.S. +, Ont. +, P.E.I. +, Que. +, Ala. +, Ark. +, Conn. +, Del. +, Ga. +, Ill. +, Ind. +, Kans. +, Ky. +, La. +, Maine +, Mass. +, Md. +, Mich. +, Minn. +, Miss. +, Mo. +, N.C. +, N.H. +, N.J. +, N.Y. +, Ohio +, Oreg. +, Pa. +, R.I. +, S.C. +, Tenn. +, Va. +, Vt. +, W.Va. +, Wis. +  and in Europe +
not +  and aggregated +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
unisexual +  and bisexual +
tomentose +  and arachnoid +
cymbiform +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
tomentose +  and glabrous +
5;4;5;4;5;4;5;4;5;4 +
list +  and count +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
coriaceous +
not +  and aggregated +
not +  and aggregated +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
glabrous +  and hairy +
hemispheric +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
(2-)3-1000+-flowered +
axillary +  and terminal +
crassinucellate +
compound +  and simple +
deciduous +
craspedodromous +
coarsely serrate +  and crenate +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and apical +
branching +  and 000+-flowered +
5cm +  and 30cm +
glabrous +  and hairy +
150 +  and 15 +
3 cm30 mm <br />0.03 m <br /> (20 cm200 mm <br />0.2 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0 (?) +  and 4 (?) +
purple +, white +, usually light +  and dark-pink +
free +  and distinct +
ovate;orbiculate +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
adnate +, free +, connate +  and distinct +
not arillate +
fusiform;oblong +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 0.4 cm4 mm <br />0.004 m <br /> (?) +
deciduous +  and persistent +
free +  and distinct +
reflexed +, erect +, ascending +  and spreading +
triangular +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
2 +  and 4 +
Endemic +, Illustrated +  and Weedy +
free +  and distinct +
1 times petal length +
shorter or longer +
nectariferous +
reddish-brown +  and brown +
decumbent +  and prostrate +
erect +  and ascending +
villous;glabrous +
5 +  and 20 +
discoid +  and capitate +
deciduous +  and persistent +
distinct +
subterminal +  and terminal +
not elongate +
hairy +  and glabrous +
Spiraea tomentosa +
species +
inconspicuous +
reduced +