Great globe thistle

Echinops sphaerocephalus, the great globe thistle or pale globe thistle, is a stout, coarse herbaceous perennial in the family Asteraceae, native to central and southern Europe, the Caucasus and western Asia and naturalised as a roadside weed in parts of North America. It rises 0.5 to 2 metres from a thick taproot, with erect, longitudinally ribbed stems clothed in glandular hairs and white-cottony tomentum. The alternate, deeply pinnately lobed to pinnatifid leaves are large, 10 to 35 centimetres long, the lobes themselves toothed and tipped with weak yellowish spines; dark green and roughly hairy above, conspicuously white-felted beneath. The flower heads are uniquely arranged: numerous one-flowered florets are aggregated into a tight, perfectly globose, terminal compound head 3 to 6 centimetres in diameter, the individual involucres bristly and grey-blue when in bud, opening to pale silvery-blue or greyish-white tubular five-lobed corollas. The fruit is a small, hairy, cylindrical achene tipped with a short pappus. The plant is much visited by bees and is grown as a bold ornamental.