Strongly aromatic, spreading shrub, not dying back in winter. Stems erect, densely sericeous, becoming glabrous below, ribbed, up to 3 m tall, much-branched toward base. Lvs clustered toward tips of stems, densely sericeous on upper and lower surface, petiolate, 1-pinnate with leaflets 1-2-pinnatisect, up to c. 15 × 10 cm in lower lvs; ultimate segments narrow-oblong to linear, obtuse to subacute, 5-70 × 1.5-5 mm, with only central vein evident. Infl. paniculate; infl. lvs similar to cauline lvs but becoming apetiolate and 1-pinnatisect, finally reduced to < 1 cm long and not lobed. Involucral bracts sericeous, with narrow membranous margins and apex. Capitula (3)-4-7 mm diam.; receptacle pilose; florets many, cream to bright yellow, glabrous. Achenes not seen.