Orobanche cumana - Sunflower Broomrape

Sunflower Broomrape is an obligatory, root parasitic plant that produces leafless flowering stems 40-60 cm high bearing alternate scales less than 1 cm long. It is mostly parasitic on the roots of Artemisia and Sunflower plants. Although usually unbranched above ground, multiple stems sometimes arise from a single tubercle below ground. The plant is pale, completely lacking any chlorophyll. The base of the stem, below ground, is normally swollen and tuberous. The inflorescence, occupying up to half the length of the stems carries many acropetally developing flowers, arranged in spikes or racemes, each subtended by a bract 7-12 mm long (without the additional bracteoles present in O. ramosa). The sepal-cup has four free sepals, more-or-less bitoothed, 7-12 mm long. The white flower tube, 2-3 cm long, is inflated near the base, prominently down-curved, with narrow reflexed lips, up to 1 cm across. The tube is mainly white or pale while the lips are contrastingly blue or purple, without distinct venation. Filaments are inserted in the flower tube, 4-6 mm above the base. A capsule develops up to 8-10 mm long and may contain several hundred seeds. A single plant carries 10-100 flowers and hence may produce over 100,000 seeds. Sunflower Broomrape is native to E. Europe to S. Siberia, W. & N. China, and Western Himalaya. Flowering: April-May.