Pistillate fl initially subtended by a primary bract and bracteoles, but an indefinite number (often 4) of linear-subulate secondary bracteoles arising adaxially to each of the latter, ± coalescent below, accrescent, elongating and persistent so that the pistillate infl forms a bur; ovary glabrous, without papillae; achene smooth, hard; rhizomatous, aromatic shrubs with deciduous, pinnately lobed, stipulate lvs. Monospecific.