Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Tribe: Cynareae
Genus: Carduus
Species: C. nutans
Binomial name: Carduus nutans
Common name: Nodding thistle, Musk thistle, Bastard scotch thistle.
Nodding thistle (Carduus nutans) is a member of the sunflower family Asteraceae. It is a biennial herb with showy red-purple flowers and sharply spiny stems and leaves. It is native to much of Europe and Asia except for the far north.
Mature plants range in height from 1-1.5 m tall and have multi-branched stems. The leaves are dark green, coarsely bipinnately lobed, with a smooth, waxy surface and sharp yellow-brown to whitish spines at the tips of the lobes. They are more or less hairy on top and woolly on the veins below. The large globose flower heads, containing hundreds of tiny individual flowers, are 3-5 cm (rarely to 7 cm) diameter and occur at the tips of stems.
The flower heads commonly droop to a 90° to 120° angle from the stem when mature, hence its alternate name of "Nodding thistle". Each plant may produce thousands of straw-coloured seeds adorned with plume-like bristles. They are 4 to 6 cm across, with purple-red bracts.The stem is cottony/hairy.
See Taranaki Regional Council web site for more details about this pest plant.http://www.taranakiplants.net.nz/weeds/pestplants/nod_thistle.html
A photo showing the details of the leaves
Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/