Family: Orobanchaceae
Orobanche image
Derek Anderson  

Key to Wisconsin Orobanche (=Aphyllon)

Author: John G. Zaborsky

    • 1a. Flowers sessile or nearly so, borne in dense spikes; calyx subtended by (1–) 2 bracts O. ludovicianum

    • 1b.Flowers solitary on naked, scapose pedicels; calyx without subtending bracts 2

    • 2a.Plant with an above-ground stem bearing a cluster of long-pediceled flowers at its apex; bracts glandular-pubescent O. fasciculatum

    • 2b.Plant without an above-ground stem, the long pedicels arising from a short base; bracts glabrous or nearly so O. uniflorum

Using molecular data, Schneider (2016) showed that the New World taxa of Orobanche are not closely related to those found in the Old World.  He resurrected the genus Aphyllon to accommodate our three species, as well as others to the west and south.  The common name comes from the Latin word for tuber,“rapum”, and the common name for Genista (Fabaceae), “broom”.  Some species of Orobanche parasitize Genista species and form tuberous growths where the parasite infects the host.