You selected Achillea nigrescens (E.Mey.) Rydb. This is a synonym for:

Accepted scientific name:
Achillea millefolium L. (provisionally accepted name)
Synonyms:
Achillea albida Willd. (synonym)
Achillea alpicola (Rydb.) Rydb. (synonym)
Achillea ambigua Boiss. (synonym)
Achillea ambigua Pollini (synonym)
Achillea anethifolia Fisch. ex Herder (synonym)
Achillea angustissima Rydb. (synonym)
Achillea arenicola A.Heller (synonym)
Achillea bicolor Wender. (synonym)
Achillea californica Pollard (synonym)
Achillea ceretanica Sennen (synonym)
Achillea compacta Lam. (synonym)
Achillea coronopifolia Willd. (synonym)
Achillea crassifolia Colla (synonym)
Achillea cristata Hort. ex DC. (synonym)
Achillea cuspidata Wall. (synonym)
Achillea dentifera Rchb. (synonym)
Achillea eradiata Piper (synonym)
Achillea fusca Rydb. (synonym)
Achillea gigantea Pollard (synonym)
Achillea gracilis Raf. (synonym)
Achillea haenkeana Tausch (synonym)
Achillea intermedia Schleich. (synonym)
Achillea lanata Lam. (synonym)
Achillea laxiflora A.Nelson (synonym)
Achillea laxiflora Pollard & Cockerell (synonym)
Achillea magna All. (synonym)
Achillea magna Haenke (synonym)
Achillea magna L. (synonym)
Achillea marginata Turcz. ex Ledeb. (synonym)
Achillea megacephala Raup (synonym)
Achillea nabelekii Heimerl (synonym)
Achillea nigrescens (E.Mey.) Rydb. (synonym)
Achillea occidentalis (DC.) Raf. ex Rydb. (synonym)
Achillea ochroleuca Eichw. (synonym)
Achillea ossica K.Koch (synonym)
Achillea palmeri Rydb. (synonym)
Achillea pannonica Scheele (synonym)
Achillea pecten-veneris Pollard (synonym)
Achillea pratensis Saukel & R.Länger (synonym)
Achillea pseudotanitifolia Wierzb. ex Rchb. (synonym)
Achillea puberula Rydb. (synonym)
Achillea pumila Schur (synonym)
Achillea rosea Desf. (synonym)
Achillea seidlii J.Presl & C.Presl (synonym)
Achillea setacea Schwein. (synonym)
Achillea sordida (W.D.J.Koch) Dalla Torre & Sarnth. (synonym)
Achillea subalpina Greene (synonym)
Achillea subhirsuta Gilib. (synonym)
Achillea submillefolium (synonym)
Achillea sylvatica Becker (synonym)
Achillea tanacetifolia Mill. (synonym)
Achillea tenuifolia Salisb. (synonym)
Achillea tenuis Schur (synonym)
Achillea tomentosa Pursh (synonym)
Achillea virgata Hort. ex DC. (synonym)
Achillios millefoliatus St.-Lag. (synonym)
Alitubus millefolium (L.) Dulac (synonym)
Alitubus tomentosus Dulac (synonym)
Chamaemelum millefolium (L.) E.H.L.Krause (synonym)
Chamaemelum tanacetifolium (All.) E.H.L.Krause (synonym)
Chamaemelum tomentosum (L.) E.H.L.Krause (synonym)
Common names: -
Classification:
Plantae
Phylum Magnoliophyta
Class Magnoliopsida
Order Asterales
Family Asteraceae
Genus Achillea
Distribution: -
Additional data: Data Providers: CONABIO, Caribbean Checklist, African Flowering Plants Database, SANBI, New Zealand Plant Name Database, Flora Malesiana, IPNI, Flora of Korea, Govaerts World Compositae Checklist A-G, LCR Editor, MesoAmericana, Flora of China Checklist, . GCC LSID: urn:lsid:compositae.org:names:40160FE1-53D5-4C15-9595-F5B87A104673
Source database: GCC, 1 (Beta), Nov 2009
Latest taxonomic scrutiny: Flann C., 13-Nov-09
Online resource: -
CoL taxon LSID: urn:lsid:catalogueoflife.org:taxon:1f48c9b2-60a7-102d-be47-00304854f810:ac2010