Ivy Broomrape (Orobanche hederae) is thriving in the grounds of Benslow music school. That is intriguing because Brian Sawford characterised it as "one of Hertfordshire's rarest wildflowers" in his excellent book 'Wild Flower Habitats of Hertfordshire' which was published in 1990. 

 He notes that "it was unexpectedly discovered in a churchyard in northern Hertfordshire in 1984, parasitic upon Ivy tumbling over a few ancient limestone tombstones and by an adjacent gravel drive". Moreover he states that "These are the only colonies of this normally maritime species ever known from the county, and the only location in the whole of the Eastern part of Britain, north of the River Thames". He speculates that seeds may have clung to the tombstones quarried on the Isle of Portland in Dorset. As he alludes to O. hederae is an obligate parasite without chlorophyll and its host plant is Ivy.

 Ordinarily we might assume that rare wildflowers are getting rarer. However the 2020 Plant Atlas of the Botanical Society of Britain and Ireland describes coastal populations as stable but increasing in gardens and urban areas. It speculates this may be by wind dispersal or as a contaminant of top soil.

 I came across an article from 2019 in the Benslow newsletter by Gill Langley "Hitchin resident and Broomrape enthusiast". At the time she reckoned there were at least 130 plants there (I haven't counted!) and mentions five other sites in the county. Has O. hederae increased since that first discovery in 1984 or has it simply been noticed in other locations?

 How it came to be at the music school is a mystery. Benslow was formerly a rather grand country house and grounds; numerous wild species persist albeit surrounded by the expansion of Hitchin. Then again building works have taken place and Jif has developed the gardens with substantial planting over the course of several decades. Possibly the seeds and/or tissue arrived as 'contaminants'? Or perhaps the seed blew in on the wind and found ideal conditions?

 For whatever reason the rare and wonderful Ivy Broomrape is well established at Benslow.