Pilosella aurantiaca (Orange Hawkweed)

On National Environmental Alert List. Pest plant ACT. General Biosecurity Duty NSW with additional restrictions all NSW (as Hieracium species).  

http://weeds.dpi.nsw.gov.au/Weeds/Details/156

Orange Hawkweed has the potential to become a significant weed within the ACT.

The general appearance of a hawkweed plant is similar to a dandelion (Taraxacum officinale) or a flatweed (Hypochaeris species). Hawkweeds are perennial herbs of variable height (15–40 cm), and have a milky sap which is seen when their stems or leaves are broken.

Key identification features

• Leaves are stalkless, hairy on both surfaces, with smooth or slightly toothed margins and are sometimes ‘sticky’ to touch. They occur in rosettes. Occasionally 2–4 alternate leaves appear near the base of the upright flower stem.
• Flowers are yellow, orange or red and ‘daisy-like’. They may be solitary or formed in a cluster of 5 to 30 flower heads. The flowers are 10–20 mm in diameter with square-ended petals, and grow on stems up to 40 cm. The flower stems are covered in short, stiff hairs.
• Seeds are purplish-black and ribbed with a bristly tuft up to 6 mm long.