Knapweed

Plectocephalus is a genus of flowering plants in the tribe Cardueae within the family Asteraceae, it contains seven described species mostly found in Americas and one in Africa.

Species

Plectocephalus americanus (Nutt.) D.Don - Mexico (Coahuila, Tamaulipas, Nuevo León), United States (AZ NM TX LA AR MS KS MO IL WI SC NY)

Plectocephalus cachinalensis (Phil.) N.Garcia & Susanna - Atacama Region in Chile

Plectocephalus chilensis G.Don ex Loudon - Chile

Plectocephalus floccosus (Hook. & Arn.) N.Garcia & Susanna - Chile (Coquimbo + Valparaíso)

Plectocephalus rothrockii (Greenm.) D.J.N.Hind - Mexico (from Chihuahua to Chiapas), United States (AZ NM)

Plectocephalus tweediei (Hook. & Arn.) N.Garcia & Susanna - Brazil (Rio Grande do Sul), Paraguay (Guairá), Uruguay, Argentina (Buenos Aires, Chaco, Misiones, Corrientes, Entre Ríos, Formosa)

Plectocephalus varians (A.Rich.) - Ethiopia

Formerly included

Plectocephalus dracaenoides (Johow) F.H.Hellw. - Centaurodendron dracaenoides Johow