About Orobanche alba Steph. ex Willd.
Orobanche alba Steph. ex Willd. is a short reddish annual plant that produces simple flowering stems, growing between 8 and 25 centimetres (3.1 to 9.8 inches) tall. This species has fragrant flowers, with a cylindrical bell-shaped (cylindrical campanulate) corolla that contains dark glands. Its calyx teeth are typically entire, meaning each tooth is formed of a single unbroken piece. It generally flowers from May to June, though in rare cases flowering can continue into early September, and it is pollinated by bumblebees. Orobanche alba is most often found on dry, sunny slopes, in steppes, and in subalpine and alpine grasslands. It grows in calcareous, alkaline, sandy, or loamy soil. It is a parasitic plant that feeds on members of the mint plant family. It most commonly parasitises plants in the genera Thymus and Salvia, but can also parasitise genera Clinopodium, Acinos, Origanum, Satureja, and Stachys. Like all Orobanche species, this plant can only parasitise specific host plants. Its seeds must come into contact with chemical signals from the roots of a host plant, such as strigolactones, in order to germinate.
