My last blog was on the common broomrape, Orobanche minor, the only species I had seen on campus in the past few years. Today I was excited to receive an email from Phöbe, one of the volunteer Friends of the Haris Garden and a very keen Cyclamen grower. The email included this image of a broomrape growing under the wingnut trees in the Harris Garden.
We have a historic record of Orobanche hederae on campus but this is undated. Looking on the BSBI mapping website there are few records for O. hederae in the vicinity. The grid square that covers the University campus has only two records, one pre 1999 and the other pre-1930. Given that our mystery broomrape was sprouting from amongst ivy shoots there was a real possibility this photo was the rediscovery of Ivy Broomrape on campus.
A quick trip from my office at lunchtime was sufficient to find the flowers of this parasitic plant growing just inside the entrance to the garden (Decimal Degrees 51.4373, -0.9410). Careful gathering of one flower stalk allowed me to key out the specimen in the herbarium and check it against authentic material. Reddish stem, brownish purple corolla that is sparsely hairy, stigma a strong yellow and growing on Hedera. Conclusion – this really is Orobanche hederae.