Professor John Stevens Henslow

Henslow Portrait E IV 7 350dpi

by Professor John Parker (Director 1996 – 2010)

As you walk around the Western half of the Botanic Garden you are experiencing and enjoying the Botanic Garden of John Stevens Henslow (left and below holding a Herbarium Sheet).  His intellectual vision, political skills, humanity and persistence brought the Garden into being, and we have been left with a priceless treasure.

Henslow with Herbarium sheet

John Stevens Henslow accepted the Chair of Botany in 1825 at a time that the study of botany was at a very low ebb in the University.  It had suffered from the absenteeism from Cambridge of his predecessor [Thomas Martyn] for 30 years.  No lectures had been given during this long period, and the Botanic Garden in the centre of the city was struggling.  The young and vigorous Henslow came to his post with a very different perspective.  He took a degree in mathematics at St John’s, had been a natural historian from boyhood, studied the new disciplines of geology and mineralogy from undergraduate days, and had been demonstrator for the chemistry practical classes of Professor James Cumming.  Henslow was a polymath indeed.  In 1823 at the age of 27, he succeeded Edward Clarke as Professor of Mineralogy.  Two years later he accepted the Chair of Botany too.

By Henslow’s day, the city centre Botanic Garden (above) was struggling due to neglect.

Henslow inherited few botanical resources in 1825:  the herbarium was rapidly decaying, and the Botanic Garden was unfit for his novel purposes.  These purposes were clear:  to provide a plant collection and facilities for a modern experimental approach to botany, not just drug plants for the education of medical students.  Botany was a serious experimental science, taking its rightful place in the upsurge of enthusiasm for the natural sciences which characterised Cambridge in the early 19th century.  Henslow was a leading light in the academic community, founding, for example, the Cambridge Philosophical Society with Professor of Geology, Adam Sedgwick.  To this day, the Society acts as a forum for debate and dissemination of knowledge concerning the natural sciences and mathematics


As a new professor, Henslow threw himself into botany, planning his lecture course, gathering together a massive herbarium of British plants for research and beginning the debate for the new Botanic Garden.  A new Garden must offer all types of plants for experimental botany – trees as well as herbs – requiring a much larger area for their growth than could be found in the city centre.  An area of cornfields just south of the city boundary, owned by Trinity Hall but rented for farming to a Reverend Bullen of Barnwell, was identified.

Murrays PlanIn 1830, the University commissioned a botanic garden plan for this entire area of about 40 acres from an architect working locally, Edward Lappidge.  This plan shows the elements we are still familiar with – a lake, a complex of systematic beds, a formal lawn, glasshouses – all set within an envelope of trees.  An 1831 Act of Parliament transferred title from Trinity Hall to the University, so all was set for development.  Just before signing the release for his tenancy, however, Rev Bullen died and his widow was pursuaded by her son-in-law to hold out for a better cash settlement of the remaining years of the tenancy.  The University was unable (or unwilling) to offer more, and so development was delayed for 13 years until the lease expired.

Life for Henslow during this period underwent a dramatic change.  In 1837, he was granted the living of the largest parish in Suffolk at Hitcham near Stowmarket.  Two years later, the Reverend Professor moved there permanently, returning to Cambridge infrequently, though he faithfully gave his botanical lectures and practical course and led botanical outings each year in May.  The University too, had changed its mind, and only sanctioned development of half of the purchased area, on grounds of expense.  The plan for this western part was drawn up by the first Curator, Andrew Murray, and it is to his hand-drawn design that planting finally began in 1846.

IMG_0553What is evident from Murray’s plan is that the structure of the western half of our current Garden remains virtually unchanged. (Left) A plan of the western Garden in Humphrey Gilbert-Carter’s 1922 guide to the Botanic Garden.)  The major insertion is the fountain built in the 1960s on the location where Murray proposed for a glasshouse range.  The lake is as planned, but has had a delightful rock garden wrapped around its eastern arm, a feature I am sure Henslow would have approved of, emphasising as it does biodiversity and ecology.

It has become clear recently that we have been left not just a beautiful physical structure, but also an intellectual construction.  The Garden is organised in a highly systematised way based on the work of the Swiss botanist, Alphonse de Candolle, and expressed in the encircling ring of trees in families and the Systematic Beds themselves.

IMG_8351In addition, the trees remaining from the original planting also show us that the three strands of Henslow’s research on the nature of species – patterns of variation, the role of ‘monstrosity’ in development of diversity, and hybridisation as a test of species identity – are illustrated in living form.

Henslow was the crucial founder of the ‘new’ Botanic Garden, both as a place of study for the University and equally importantly, as a place of recreation and learning for the whole community. These founding strands – University and community – remain enshrined today in the research and public engagement work that we undertake here in the Botanic Garden.

This article first appeared in the Friends Newsletter, in 2009, as part of the celebration of the 800th anniversary of the University and the bicentenary of the birth of Charles Darwin.

2522DarwinDisplay JPProfessor John Parker’s Walking with Henslow’s Garden tour can be downloaded from the University of Cambridge Audio Walks website.  The walk lasts between 30 – 45 minutes. 

Read more about John Stevens Henslow’s historic Garden on the Cambridge University Botanic Garden website.

IMG_9883Today, Charles Darwin’s specimens from the voyage of the Beagle, along with other historically significant collections are to be found in the University of Cambridge Herbarium. It was thanks to Darwin’s friendship with his mentor, John Stevens Henslow, that the collection is preserved in Cambridge.  Read more about the University Herbarium.