Classification
Class
Magnoliopsida Brongn.
Order
Asterales Link
Family
Compositae Giseke
Genus
Gamochaeta Wedd.
 Nomenclature
Scientific Name:
Gamochaeta americana (Mill.) Wedd., Chlor. And. 151 (1856)
Synonymy:
  • ≡ Gnaphalium americanum Mill., Gard. Dict., ed. 8. (unpaged) (1768)
  • = Gnaphalium spicatum Lam., Encycl. [J. Lamarck & al.] 2, 757 (1786) nom. illeg., non Gnaphalium spicatum Mill. 1768
  • ≡ Gnaphalium coarctatum Willd., Sp. Pl., ed. 4 [Willdenow] 3(3), 1886 (1803) nom. nov. pro Gnaphalium spicatum Lam. 1786
  • ≡ Gamochaeta spicata (Lam.) Cabrera, Bol. Soc. Argent. Bot. 9: 380 (1961) nom. illeg.
  • ≡ Gamochaeta coarctata (Willd.) Kerg., Lejeunia 120: 104 (1987)
  • = Gnaphalium purpureum var. spicatum Klatt, Linnaea 42: 140 (1878)
 Description

Annual or biennial, 10–30 cm tall, usually branched only at base; stems 1-several, erect or ascending. Basal lvs usually present at flowering, sometimes dead but persistent, apetiolate, elliptic-oblong to spathulate, 25–70 mm long. Lower cauline lvs apetiolate, densely white-tomentose on lower surface, usually glabrous but sometimes with a few hairs on upper, discolorous, plane, narrow-spathulate to almost linear, obtuse to acute, shortly mucronate, usually flat, sometimes undulate, 20–35 × 2–8 mm; uppermost cauline lvs smaller, often folded, undulate and linear. Capitula in dense terminal and axillary clusters; clusters forming a dense terminal spike and sometimes scattered below. Involucral bracts oblong, apiculate, 3.5–4.2 mm long; stereome green or reddish purple; lamina pale brown, usually with darker markings toward base; gap and margins clear; outer bracts glabrous. Achenes minutely papillate, c. 0.6 mm long.

[From: Webb et al. (1985) Flora of New Zealand. Volume 4 as Gnaphalium americanum Mill.]

 Biostatus
Exotic
 Bibliography
Anderberg, A. A. 1991: Taxonomy and phylogeny of the tribe Gnaphalieae (Asteraceae). Opera Botanica 104: 1–195.
Cabrera, A. L. 1961: Observaciones sobre las Inuleae-Gnaphalineae (Compositae) de America del Sur. Boletín de la Sociedad Argentina de Botánica 9: 359–386.
Drury, D. G. 1971: The American Spicate Cudweeds Adventive to New Zealand: (Gnaphalium Section Gamochaeta - Compositae). New Zealand Journal of Botany 9(1): 157–185. [as Gnaphalium americanum Mill.; Gnaphalium coarctatum Willd.]
Freire, S.E.; Grossi, M.A.; Iharlegui, L.; Abarca, C.L.; Monti, C.; Bayón, N.D. 2021: Taxonomic iIdentity of Gamochaeta americana and Gamochaeta coarctata (Gnaphalieae, Asteraceae). Phytotaxa 523(4): 273–283.
Kerguélen, M. 1987: Données taxonomiques, nomenclaturales et chorologiques pour une révision de la flore de France. Lejeunia 120: 1–264.
Klatt, F.W. 1878: Die Gnaphalien Amerikas. Linnaea 42: 111–144.
Lamarck, J.B.A.P.M. de 1786–1788: Encyclopédie Méthodique. Botanique. Vol. 2. Panckoucke, Paris.
Miller, P. 1768: The Gardeners Dictionary. Vol. No. 17. Edition 8. London.
Pruski, J. F.; Nesom, G. L. 2004: Gamochaeta coarctata, the correct name for Gamochaeta spicata (Asteraceae: Gnaphalieae). Sida 21(2): 711–714. [as Gamochaeta coarctata (Willd.) Kerg.; Gamochaeta spicata (Lam.) Cabrera; Gnaphalium coarctatum Willd.; Gnaphalium purpureum var. spicatum Klatt; Gnaphalium spicatum Lam.]
Weddell, H. A. 1861 ("1855-1857"): Chloris Andina: Essai d'une Flore de la Région Alpine des Cordillères de L'Amérique du Sud. Vol. 1. P. Bertrand, Paris.
Willdenow, C.L. von 1803: Species Plantarum. Editio Quarta. Vol. 3(3). G.C. Nauk, Berlin.