Telegraph-weed

Heterotheca grandiflora, the telegraph-weed or telegraphplant, is a coarse aromatic biennial or short-lived perennial herb in the Asteraceae family native to California and Baja California and now naturalised across much of the south-western United States. The plant grows fifty centimetres to two metres tall with a strongly tap-rooted base and a single erect, leafy stem that branches in the upper portion. The alternate leaves are oblong to lance-shaped, densely glandular-hairy on both surfaces, sticky to the touch, and emit a heavy resinous odour when crushed; lower leaves are stalked while upper leaves clasp the stem. From summer into autumn the plant bears numerous small bright yellow flower heads in open terminal panicles; each head is about two centimetres across with twenty to thirty short ray florets surrounding a yellow disc. The achenes of ray florets are smooth while those of disc florets bear a tawny double pappus of bristles.