Achillea millefolium

Linnaeus

Sp. Pl. 2: 899. 1753. 1753

Common names: Common yarrow achillée millefeuille herbe-à-dinde
Illustrated
Synonyms: Achillea alpicola (Rydberg) Rydberg Achillea arenicola A. Heller Achillea borealis subsp. arenicola (A. Heller) D. D. Keck Achillea borealis subsp. californica (Pollard) D. D. Keck Achillea californica Pollard Achillea gigantea Nuttall Achillea lanulosa Pollard & Cockerell Achillea lanulosa subsp. alpicola (Rydberg) D. D. Keck Achillea laxiflora (E. Meyer) Rydberg Achillea megacephala (de Candolle) Rafinesque ex Rydberg Achillea millefolium var. alpicola (Rydberg) Garrett Achillea millefolium var. arenicola (A. Heller) Nobs Achillea millefolium var. asplenifolia (Ventenat) Farwell Achillea millefolium subsp. borealis (Bongard) Breitung Achillea millefolium var. borealis (Bongard) Farwell Achillea millefolium var. californica (Pollard) Jepson Achillea millefolium var. gigantea (Pollard) Nobs Achillea millefolium subsp. lanulosa (Nuttall) Piper Achillea millefolium var. lanulosa (Nuttall) Piper Achillea millefolium var. litoralis Ehrendorfer ex Nobs Achillea millefolium var. maritima Jepson Achillea millefolium var. megacephala (Raup) B. Boivin Achillea millefolium var. nigrescens E. Meyer Achillea millefolium var. occidentalis de Candolle Achillea millefolium var. pacifica (Rydberg) G. N. Jones Achillea millefolium var. puberula (Rydberg) Nobs Achillea nigrescens Achillea occidentalis Achillea pacifica Achillea puberula Achillea rosea Achillea subalpina
Treatment appears in FNA Volume 19. Treatment on page 493. Mentioned on page 492.

Perennials, 6–65+ cm (usually rhizomatous, sometimes stoloniferous). Stems 1 (–4), erect, simple or branched, densely lanate-tomentose to glabrate. Leaves petiolate (proximally) or sessile (distally, weakly clasping and gradually reduced); blades oblong or lanceolate, 3.5–35+ cm × 5–35 mm, 1–2-pinnately lobed (ultimate lobes ± lanceolate, often arrayed in multiple planes), faces glabrate to sparsely tomentose or densely lanate. Heads 10–100+, in simple or compound, corymbiform arrays. Phyllaries 20–30 in ± 3 series, (light green, midribs dark green to yellowish, margins green to light or dark-brown) ovate to lanceolate, abaxial faces tomentose. Receptacles convex; paleae lanceolate, 1.5–4 mm. Ray-florets (3–) 5–8, pistillate, fertile; corollas white or light pink to deep purple, laminae 1.5–3 × 1.5–3 mm. Disc-florets 10–20; corollas white to grayish white, 2–4.5 mm. Cypselae 1–2 mm (margins broadly winged). 2n = 18, 27, 36, 45, 54, 63, 72 (including counts from Europe).


Phenology: Flowering late Apr–early Jul (south), mid Jul–mid Sep (north).
Habitat: Pastures, meadows, roadsides, stream sides, woodlands, waste grounds, dry or sandy soils, also in damp, clayey, and salty soils
Elevation: 0–3600 m

Distribution

Greenland, St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Mexico, Eurasia

Discussion

Achillea millefolium is morphologically variable and has been treated as either a single species with varieties or as multiple distinct species. At least 58 names have been used for North American specimens. Some early workers (e.g., J. Clausen et al. 1948) thought the native North American plants were taxonomically distinguishable from introduced, Old World plants. Other workers (e.g., R. J. Tyrl 1975) have treated A. millefolium as a cosmopolitan, Northern Hemisphere polyploid complex of native and introduced plants that have hybridized, forming diploid, tetraploid, pentaploid, hexaploid, septaploid, and octoploid plants and/or populations constituting a single, variable species.

Morphologic characters that have been used to segregate these populations into species and/or varieties include: (1) degree and persistence of tomentum; (2) phyllaries with greenish, light brown, or dark brown margins; (3) shapes of capitulescences (rounded or flat-topped); and (4) degrees of leaf dissection and shapes of lobes.

While examining specimens for this treatment, two general trends were noted: (1) Plants growing either at high latitudes or high elevations tend to have darker colored margins on the phyllaries. (2) Plants at high latitudes or elevations or from extreme desert locations tend to be more densely lanate than plants from less extreme habitats. These are only trends; variations in local populations due to local environmental conditions are to be expected.

An ecomorphotype adapted to the Athabasca sand dunes of northern Saskatchewan has been known as A. megacephala or A. millefolium var. megacephala and has been treated as a taxon of special concern in Canada (V. L. Harms 1999).

Selected References

None.

Lower Taxa

None.

... more about "Achillea millefolium"
72 +, 63 +, 54 +, 45 +, 36 +, 27 +  and 18 +
glabrate +  and sparsely tomentose +
not tailed +  and obtuse +
unequal +
scarious +
corymbiform +, compound +  and simple +
indeterminate +  and determinate +
Debra K. Trock +
Linnaeus +
decurrent +
compound +  and simple +
3.5 cm35 mm <br />0.035 m <br /> (35 cm350 mm <br />0.35 m <br />) +
lobed;lanceolate;oblong +
5mm;35mm +
Common yarrow +, achillée millefeuille +  and herbe-à-dinde +
zygomorphic +, actinomorphic +  and (3-)5-merous +
white +  and grayish white +
0.2 cm2 mm <br />0.002 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
winged +  and monomorphic +
oblong +  and obovate +
fertile +  and bisexual +
fertile +  and bisexual +
Greenland +, St. Pierre and Miquelon +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. +, N.W.T. +, N.S. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Ala. +, Alaska +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Mont. +, Nebr. +, Nev. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Vt. +, Va. +, Wash. +, W.Va. +, Wis. +, Wyo. +, Mexico +  and Eurasia +
0–3600 m +
glabrate +  and sparsely tomentose or densely lanate +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Pastures, meadows, roadsides, stream sides, woodlands, waste grounds, dry or sandy soils, also in damp, clayey, and salty soils +
in subcapitate clusters +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
campanulate;hemispheric +
1.5mm;3mm +
orbiculate +  and suborbiculate +
1.5mm;3mm +
sessile +  and petiolate +
cauline +  and basal +
deltate +
entire +  and dentate +
unequal +
2-carpellate +
lanceolate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
membranous +
persistent +
Flowering late Apr–early Jul (south), mid Jul–mid Sep (north). +
3 +, 20 +  and 30 +
subequal +  and unequal +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
Illustrated +
branched +  and simple +
1 (?) +  and 4 (?) +
appendaged +  and truncate +
papillate +
Achillea alpicola +, Achillea arenicola +, Achillea borealis subsp. arenicola +, Achillea borealis subsp. californica +, Achillea californica +, Achillea gigantea +, Achillea lanulosa +, Achillea lanulosa subsp. alpicola +, Achillea laxiflora +, Achillea megacephala +, Achillea millefolium var. alpicola +, Achillea millefolium var. arenicola +, Achillea millefolium var. asplenifolia +, Achillea millefolium subsp. borealis +, Achillea millefolium var. borealis +, Achillea millefolium var. californica +, Achillea millefolium var. gigantea +, Achillea millefolium subsp. lanulosa +, Achillea millefolium var. lanulosa +, Achillea millefolium var. litoralis +, Achillea millefolium var. maritima +, Achillea millefolium var. megacephala +, Achillea millefolium var. nigrescens +, Achillea millefolium var. occidentalis +, Achillea millefolium var. pacifica +, Achillea millefolium var. puberula +, Achillea nigrescens +, Achillea occidentalis +, Achillea pacifica +, Achillea puberula +, Achillea rosea +  and Achillea subalpina +
Achillea millefolium +
Achillea +
species +
campanulate +
flattened +
6 cm60 mm <br />0.06 m <br /> (65 cm650 mm <br />0.65 m <br />) +
shrub +  and subshrub +