The BSBI has a project for England: finding plants in hectads where they haven't been seen since 1999, but were present between 1950 and 1999.  This is called Project LORE.  For vc 29 there are quite a lot of such apparently missing species, with a concentration in the chalk arable and grassland areas. There is a general list of species which gives the hectads from which they are apparently missing and a detailed spreadsheet, which gives the last location(s) where they were seen, sometimes in duplicate.  Note that some positions and identifications may be erroneous.  Many sites are on private land and you should not trespass.  Do get out and have a look where there is public access - and let me have the records, along with a report of anything of interest, either for publication in the Flora Group newsletter or in English Botanical News.

There are 665 tetrads in the county. 442 are completely within the county and 111 have less than half their area within the county. The median number of taxa per tetrad in the county is 304 (278 post 2000), so a well recorded tetrad will probably have around this number of species within it. Fenland generally has fewer species, whilst urban and southern areas have more.  At the start of 2026 the tetrad with the most taxa ever recorded was TL45P (Central Cambridge) with 1141 (1084), followed by TL45N (South Cambridge) with 1137 (1047), TL45U with 1081 (1024) and TL45J (West Cambridge) with 1073 (1052).  Outside the Cambridge area, the most species rich tetrad is TL58K (Ely) with 868 (785), followed by TL25F (Gamlingay south) with 662 (529), TL49E (March, Whitemoor) with 657 (601) and TL25G (Gamlingay north) with 643 (545).

In 2024 the CNHS field studies returned to the tetrad TL45J, where they began in 2004, when it turned out to be one selected by the BSBI for its local change project. Whilst much has changed since then, new plants continued to be found. Monads in Cambridge were recorded at the 1 km level of precision for the Natural History of Cambridge project, and the resulting book was published in October 2022.  Post 2019, the monad TL4458 has the most species with 657 (885 in total and 850 post 2000), followed by TL4557 with 617 (763, 715).

Other recording projects could involve thorough surveys of a site, tetrad or parish.  Making regular visits over different months and years will give a comprehensive flora.  Even apparently very well recorded sites will have species that have been missed on previous visits, or have plants that have only recently arrived, so there is always a chance of finding something new.  Many sites are not as well recorded as they seem when looked at a finer resolution than tetrad.  At a tetrad level visits to tetrads A, J and W are particularly valuable as these form the basis of local change monitoring; where possible these tetrads could be fully recorded by individual monad. The local change project is likely to be repeated in the near future, with tetrads TF41A, TL45A, TL45J, TL45W, TL48A, TL48J and TL48W entirely within the county and TL15W having most of one monad in the county. Of these TL48J has the lowest taxon count (292 taxa, 279 species) whilst TL45J has the highest (1075, 1001 species). Another recording project would be to find or re-find plants on the Register of Plants of Conservation Concern, particularly those that have not been seen for some time. 

A good record will include: what you saw, where you saw it, when you saw it and who you are.  For something unusual, comments such as the number of plants, their status, habitat, a description of the site, associated plants etc is helpful.  For a critical or difficult species a voucher specimen may be needed. 

Our records are shared with CPERC, who in turn share their records with us.

Recording Aids:
Recording card:  vc 29 blank record sheet This prints double sided on a laser printer, though you may need to set flip page.  This version is optimised for vc 29 and marks common species and those of conservation concern. Updated 2025 March 16 to Stace IV names.
County Plant Notes: Draft of a booklet giving partial keys and tips on some plant identifications.  A new edition is planned.
Data entry:  The BSBI recording app is recommended. Alternativelly there is this Excel spreadsheet with visual basic front end for entering records.  This is modified from the Sussex Species Recorder.  It is optimised for vc 29, so that the commonest species should come up first.  Instructions for use.
Vice county boundaries: The vc boundaries are often different to the modern county boundaries and this site maps where they actually are.  The definitive boundary of vc 29 was first published in 1983 in A Checklist of the Flora of Cambridgeshire by G Crompton and H L K  Whitehouse and was redrawn by T J Bennett and G Crompton in 1990.

County Plant Lists
These lists are drafts and do contain errors.  

Common plants: This list of common plants includes those species which are present in more than twenty percent of county monads. In general, species on this list can be recorded to 1 km resolution and do not require confirmation. [Updated 2025 March 16]

Full plant list:  This county plant list includes all those plants in the BSBI database for the county  [updated 2025 March 16]; it may have omissions and errors.  It needs to be read in conjunction with the contents list of the Cambridgeshire Flora Records.  A more complete list that will form the vice-county checklist will be prepared in due course.

Plants of Conservation Concern: 

• The county Register of Plants of Conservation Concern (RPCC, Edn 16) [updated 2026 January]  meets the 2017 BSBI guidelines for a Rare Plant Register and is the county Rare Plant Register. The list is also available on the DDb. Edn 17 will provide the species listings as an online spreadsheet (draft) with a text introduction (draft).
• The RPCC  combines those species listed in Part 1 of the Cambridgeshire Flora Records with native or archaeophyte plants known from the county and on either the Great Britain or England Red Lists or scarce in the county, at differing levels of rarity and threat, together with plants in decline in the county. 
• This list of rare plants not seen recently, which puts plants in decadal classes and gives where they were last seen may help target efforts to re-find plants which are currently lost.  [Updated 2026 January 7]
• The BSBI Recording app will tell you if a plant is on the RPCC. This [dated] two page short-form list of scarce plants is designed for use in the field [Revised 2021 January 20].  Locally common species should be recorded at 100 m resolution (6-figure grid reference), whilst rarer or more threatened species need 10 m resolution (8-figure grid reference).  For plants in the latter group please give full details, such as habitat, number of plants etc. When the BSBI updates MapMate to Stace 4 names it will be updated.

Local groups with botanical interests:  The Cambridgeshire Flora Group has meetings during the season, trying to re-find historical records and visiting interesting sites, with some visits to under-recorded areas.  The Cambridge Natural History Society also has meetings that more often than not have a botanical bias.  These are mostly visits to local sites and each year the Society makes monthly visits to a smaller area near Cambridge for a comprehensive survey of its flora and fauna.  A large part of the County is within the Fenland Flora Project organised by Jonathan Graham and Owen Mountford, which is now being written up and is scheduled for publication in 2024.  There are also several U3A Botany Groups based within the County.

Local publications
The Nature of Cambridge, the report of the NatHistCam project was published in 2022 October.
A new key to Elms by Brian Eversham is largely based on local specimens
Flora of Cambridgeshire, Alan C Leslie, RHS (2019) is the most comprehensive Flora of the county yet published.
A Flora of Cambridgeshire, F H Perring, P D Sell and S M Walters (1964)
A Checklist of the Flora of Cambridgeshire, G. Crompton and H.L.K. Whitehouse (in collaboration with G.M.S. Easy and A.C. Leslie) (1983)
The Flora of Ely, R M Payne (2002)
Wildflowers of Haddenham Parish (2011)
Vice-county Census Catalogue of vascular Plants of Great Britain, Ed. C.A. Stace et al. (2003) 
Cambridgeshire Flora Records - Gigi Crompton's compendium of historical records since 1538, which includes a rare plant section, and equates to a county checklist (2001 - 2004)
John Ray's Cambridge Catalogue, Ed. P H Oswald and C D Preston (2011) 

Cambridge University Herbarium
The Herbarium is a very useful facility for checking specimens against vouchers that have been determined by experts.  You can arrange to use the collections for research by contacting herbarium [at] plantsci.cam.ac.uk . Please note that all specimens being brought into the Herbarium must be frozen in the on-site freezer for a minimum of three days before they can taken into the collections for comparison and you will need to arrange this with the Herbarium before your study visit.  If you are interested in volunteering at the Herbarium, please contact the Herbarium more volunteering opportunities are planned for the future.