Dr Mark Spencer FLS

Dr Mark Andrew Spencer
  • Senior Curator, British and Irish Herbarium
  • Life Sciences department
  • Plants Division
Natural History Museum
Cromwell Road


My life-long passion for plants was fuelled by a childhood spent wandering the Lizard peninsula, Cornwall and the Northamptonshire countryside. In 1989 I moved to London to study Horticulture at Kew Gardens. My first degree was in Botany, and my PhD (both at the University of Reading) was on the systematics of Peronospromycetes (water mould fungi). I am committed to engaging with and educating the wider British public about the value and interest of Britain’s flora. My botanical interests are wide-ranging but currently are particularly focused on the historic and non-native floras of London and the Isles of Scilly. I am the Botanical Society of the British Isles vice-county recorder for Middlesex and the Vascular Plant Recorder for the London Natural History Society. Since 2011 I have also started doing Forensic Botany and have participated in several major criminal investigations.

Recent Career

2012        Senior Curator, British and Irish Herbarium, Department of Life Sciences, 
                 Natural History Museum, London
2008        Senior Curator, British and Irish & Sloane Herbariums, Department of Botany, 
                 Natural History Museum, London
2006        Curator, British & European Herbariums, Department of Botany, 
                 Natural History Museum, London
2004        Research Botanist, Linnaean Plant Name Typification Project, Department of Botany, 
                 Natural History Museum, London  
2002        Field Botanist and Habitat Surveyor, London Wildlife Trust                                                


2003        PhD ‘Molecular phylogenies and systematics of the Peronosporomycetes’ - 
                 University of Reading
1998        1st Class BSc Honours Degree in Botany - University of Reading

Expertise & Interests

British and Irish Botany

  • The native and non-native flora of Greater London, Cornwall and the Isles of Scilly
  • The impact of climate change upon phenological events, non-native species and floristic composition
  • The Scottish Highland collections of Robert Brown in the 1790’s

Forensic Botany

  • Crime scene vegetation analysis, particularly at grave or deposition scenes.
  • Vegetation fragment comparison and analysis between crime scenes and associated locations.


Historic Collections

  • The herbarium of Sir Hans Sloane, particularly the British and Irish collections of Rev. Adam Buddle, Samuel Dale, Edward Lhwyd, Richard Richardson and others
  • The ‘Linnaean’ herbariums of Paul Hermann, George Clifford and John Clayton


  • Field mycology in the London area
  • The systematics and identification of Peronosporomycetes (oomycetes or water moulds)

Professional Roles


Strategic Innovation Fund, Natural History Museum, grant to identify key Museum collections with potential for climate change research. Subsequent grant money to further investigate the value of Museum UK collections for phenological research.


In partnership with the Botanical Society of the British Isles, the Museum is databasing specific collections of UK rare and endangered species.   

Committees, appointments

2006                Committee Member, UK Biodiversity Research Advisory Group
2006                Vice-county Recorder for Middlesex, Botanical Society of the British Isles
2006                Vascular Plant Recorder, London Natural History Society
2006                Committee Member, Recorders Advisory Group for Greenspace Information for
                         Greater London (the regional biological records centre)
2006                Committee Member, Habitats, Species and Data Working Group of the London
                         Biodiversity Partnership
2001                Fellow, Linnean Society of London
2006-2009     Council Member, London Natural History Society
2006-2009     Council Member, Botanical Society of the British Isles
2003-2007     Council Member, London Wildlife Trust


I manage the following Natural History Museum herbariums:

The British and Irish Herbarium

The British and Irish Herbarium is the most comprehensive and the largest collection of flowering plants (and some conifers) from the British Isles, comprising 620,000 specimens. 
The scope of collections:

  • Date from the late 17th Century to the present day.
  • The geographic scope of collections covers the whole of the British Isles as well as the Channel Islands.
  • The British and Irish Herbarium houses conifers and flowering plants; the remaining groups found in the British Isles are managed within relevant the cryptogamic herbarium sections. The majority of the collection is of native taxa, although non-cultivated non-natives are also represented. The collections are particularly rich in the apomictic genera Hieracium, Taraxacum, Rubus and Sorbus.
  • Major collections include those of C.C. Babington, J. Banks, R. Brown, E. Forster, J. Groves, F.J. Hanbury, & A.J. Wilmott.

The Sir Hans Sloane Herbarium

In his long life (1660-1753), the noted physician, scientist and collector Sir Hans Sloane amassed one of the greatest collections of plants, animals, antiquities, coins and many other objects of his time. It was to be the founding core of the British Museum and later The Natural History Museum.

The John Clayton Herbarium

John Clayton (1694-1773) was one of the early collectors of plant specimens in Virginia, where he was Clerk to the County Court of Gloucester County from 1720 until his death 53 years later. Although he published almost nothing himself, Clayton's specimens have considerable nomenclatural importance as, having reached Europe and the hands of J.F. Gronovius (1690-1762) by 1735, many of them were studied by Carl Linnaeus and were among the earliest North American specimens that he had seen.

The George Clifford Herbarium

Clifford's Herbarium consists of 3,461 sheets upon which are mounted dried plant specimens. It is probable that George Clifford established the herbarium in the Hartekamp in the 1720s, building it up with plants not only from his own garden but also from others, and from collectors around the world. In 1736, on a visit to the house of the botanist Johannes Burman (1706-1779), Clifford was introduced to the young Carl Linnaeus, who was living and working there. Linnaeus later visited Clifford's garden and impressed him with his botanical knowledge. Clifford was most keen to employ Linnaeus at the Hartekamp and, with the inducement of a volume of Sir Hans Sloane's 'Natural History of Jamaica', persuaded Burman to let Linnaeus go and join him as his physician and horticulturist. And so in 1735 Linnaeus started his 'dream job' of supervising the hothouses and naming specimens and classifying them according to his own system. During his stay he was to produce an important botanical work which is of value to taxonomists and historians to this day, the Hortus Cliffortianus, in which he described many new species from living and dried specimens in Clifford's possession.

The Paul Herman Herbarium

Paul Hermann (1646-1695) was born in Halle, the son of Johann Hermann, a well-known organist, and Maria Magdalena Röber, a clergyman's daughter. He was to make one of the earliest scientific collections of plant specimens from Sri Lanka (formerly Ceylon), where he was Medical Officer to the Dutch East India Company between 1672 and 1677. The collection itself, comprising four bound volumes containing pressed plants and a smattering of similarly preserved insects, and a volume of drawings, seems to have disappeared from sight until 1744, when it was in the possession of the Danish Apothecary-Royal, August Günther. He loaned these five volumes to Carl Linnaeus (1707-1778), who set about identifying them. The collection contained many plants new to Linnaeus, and the result was his Flora Zeylanica (1747). Later, in 1753, Linnaeus published his Species Plantarum, in which he gave modern binomial names for the first time, most of his Sri Lankan taxa being based on their earlier Flora Zeylanica accounts.


My recent research and fieldwork interests have included:

  • Aspects of botanical nomenclature, particularly typification
  • Collecting the non-native flora of Greater London and the Isles of Scilly
  • The impact of climate change upon phenological events and the distribution of British and Irish flowering plants
  • The taxonomy and systematics of Hyacinthoides and Calystegia

Students and Volunteers

I welcome the opportunity to work with students and volunteers wherever possible. 

Recent student projects have included:

  • Inventories and herbarium collections of the flora of central London
  • Herbarium techniques associated with research on hybridisation in Calystegia
  • Use of herbarium collections for phenological studies

There is a thriving volunteer programme in the British and Irish Herbarium. Currently, volunteers are:

  • Conserving, databasing and digitising the Scottish collections made by Robert Brown in the 1790’s
  • Databasing specimens from the Greater London area
  • Conserving the Rosa collection of Joseph Woods
  • Databasing UK rare and endangered species, in conjunction with the Botanical Society of the British Isles

Academic visitors

The British and Irish Herbarium is increasingly recognised as an important resource for researchers investigating biodiversity loss and the impacts of climate change as well as more ‘traditional’ taxonomic work. 

Recent work has included:

  • The impact of changing environmental conditions upon the flowering times of a range of British and Irish flowering plants
  • Digitising representative specimens of British and Irish Hieracium species for publication in a field guide
  • Mapping the distribution of the recently recognised (in the British Isles) subspecies of Baldellia ranunculoides
  • Hybridisation in British native and non-native Calystegia species
  • The past distribution of Carex flava in Great Britain


I have significant experience of broadcast media and regularly appear, on behalf of the Museum, on television. I am committed to engaging with the public and regularly give formal and informal lectures, workshops or guided walks on a wide range of subjects relating to UK biodiversity, particularly non-native species, urban botany and introductory mycology.


Brown, J.M., Brummitt, R.K., Spencer, M.A. & Carine, M.A. (2009) Disentangling the
bindweeds: hybridization and taxonomic diversity in British Calystegia (Convolvulaceae) Bot. J. Linn. Soc. 160 (4): 388-401.

Compton, J.A., Culham, A. & Spencer, M.A. (2008). Typification of the names of Cyclamen hederifolium Aiton, C. coum Miller, C. orbiculatum Miller, C. persicum Miller, C. purpurascens Miller and C. vernale Miller (Myrsinaceae). Cyclamen: 75-83.

Grundmann, M., Rumsey, F.J., Ansell, S.W., Russell, S.J., Darwin, S.C., Vogel, J.C., Spencer, M.A., Squirrell, J., Hollingsworth, P.M., Ortiz, S. & Schneider, H. (2009). Phylogeny and taxonomy of the bluebell genus Hyacinthoides, Asparagaceae [Hyacinthaceae].Taxon 59(1): 68-82.

Jarvis, C.E., Reduron, J.-P., Spencer, M.A. & Cafferty, S. (eds) (2006). Typification of Linnaean plant names in Apiaceae. Taxon 55(1): 207-216.

Jarvis, C.E., Spencer, M.A. & Cafferty, S. (eds) (2005). Typification of Linnaean plant names in Ranunculaceae. Taxon 54(2): 467-471.

Martínez-Azorín, M., Crespo, M. B. & Spencer, M. (2006). Typification of names of taxa in Orithogalum L. subg. Cathissa (Salisb.) Baker (Hyacinthaceae). Taxon 55(4): 1014-1018.

Monro, A. & Spencer, M.A. (2005). Typification of Linnaean plant names in Urticaceae.
Taxon 54(3): 796-798.

Rogers, Z.S. & Spencer, M.A. (2006). Typification of plant names in Thymelaeaceae published by Linnaeus and Linnaeus filius. Taxon 55(2): 483-488.

Spencer, M.A. (2005). Descriptions of Fungi and Bacteria: set 160 (1591-1599). CABI
Bioscience. Egham.

Spencer, M.A., Irvine, L.M. & Jarvis, C.E. (2009). Typification of Linnaean names relevant to
algal nomenclature. Taxon 58(1): 237-260.

Spencer, M.A., Vick, M.C. & Dick, M.W. (2002). Revision of Aplanopsis, Pythiopsis, and ‘subcentric’ Achlya (Saprolegniaceae) species using 18S rDNA and morphological data. Mycological Research 106: 549-560.

Spencer, M.A. & Dick, M.W. (2002). Aspects of graminicolous downy mildew biology: perspectives for tropical plant pathology and Peronosporomycetes phylogeny. In: Watling, R. et al. Tropical Mycology, Vol. 2, Micromycetes. CABl Publishing, Wallingford, UK. pp. 63-81.