Professor Crawley in 'Flora of Berkshire' (2005) observes that the total number of plant species found in the county of Berkshire varies from year to year, as new species arrive and resident species are lost. The total depends on the way you do the counting. For example , if you include the most difficult (apomictic) genera like Rubus, Taraxacum and Hieracium as well as the hybrids and subspecies, then there were 1361 native and 1030 alien 'taxa' in Berkshire, the last time the figures were counted (by Professor Stace et al in 2003). In contrast, the 'New Atlas of the British and Iris Flora' (Preston et al, 2002) which excludes most of the difficult taxa and includes only naturalised aliens has 955 native and 632 alien species for Berkshire. Just to complicate matters further, opinions differ as to whether a species is native or alien taxa has also changed fairly recently, with the adoption of a new category called 'archaeophytes' (i.e. non-native plants associated with people), most of which were formerly classified as native species. Such terminology is new to me, since I returned to taking a serious interest in British flora after a gap of some 30 years, which have been spent specialising in Himalayan flora. Only a strictly limited number of specialists can reliably recognise species within apomictic taxa, hybrids or subspecies. As to actual names, the nomenclature and taxonomic treatment of British flowers has changed substantially since I began studying its flora properly when I arrived at the University of Southampton to study botany, purchasing 'Flora of the British Isles' (Clapham, Tutin & Warburg, 1962); at that time this tome was somewhat intimidating, whilst now, I can make corrections and improvements - we all have a preference for what we are familiar with and were brought up on but I do consider that whilst the 'New Flora of the British Isles' (Stace, 1997) is certainly vastly more up-to-date nomenclature and current taxonomic treatment-wise (though all printed floras are out-of-date as soon as they are published and in this case is now 20 years ago), contains some line drawings, a few black & white photos and additional information, I find it too abbreviated, which for the less experienced is likely to lead to misidentifications compared with the 'old' flora.
If one assesses the British flora, which elsewhere in this section of the web-site, I explain has been better & more intensively studied than anywhere on earth, in International terms, one should be advised that British botanists (who we rightly consider to be amongst the best in the world and ones eager to collaborate) have been traditionally known as 'clumpers', whilst some others as 'splitters'. Clumpers tend to adopt a conservative approach to variation within species (intraspecific), tending to treat extremes of variation as merely forms, perhaps varieties and at most subspecies, rather than jumping to the often speculative conclusion that it represents a new species. Chinese botanists, tend to adopt the opposite approach, readily deciding upon new species, which has resulted in what is already a massive flora, being in numerical terms, even larger. As for India, whose botanists have been actively discouraged from collaborating Internationally (in fact many in one state are unaware of which species are recorded in bordering states or countries, leading to frequent, false claims of endemism - which means found only in a particular district, region or country), many including non-botanists, readily (again all-too-frequently incorrectly) that they have found a species 'new to science'. A recent ban on allowing type specimens to be sent abroad for study at botanical institutions will damage proper study further. Whilst one can understand patriotism, especially as there may be former colonial political undertones at play, however when science is not objective with flawed and fake results published and proclaimed, then too readily accepted by International bodies (who should know better), a serious situation exists. The flora of the Indian North-West Himalaya, which I know best (in fact know better than anyone alive, Indian or foreigner), has too many false claims of species being 'rare and endangered' or the much favoured 'critically endangered' (which actually means about to become extinct - strange that this has applied to quite a number of species for not just years but decades, none actually have - of course explained by amazing conservation measures which have been put into place... no....), most of which I know are in reality neither rare nor endangered, some actually being common and widespread, even abundant. But how would the so-called botanists who made the submissions, know, as they rarely venture out-of-their offices into the mountains!
One extraordinarily unscientific method of assessing rarity, involves checking pressed specimens in Indian herbaria; when a species has seldom, or not been collected in the decades since Indian Independence, they proclaim this is conclusive evidence that populations have decreased since the 'British days'. No, the explanation probably lies in the willingness of British, other European and American botanists to explore up steep slopes, amongst boulders, on cliffs and trek properly in the mountains. Most Indian botanists, when they occasionally do venture out, largely sit in vehicles, only follow the main routes (be they roads or tracks), perhaps reaching 100m at most from the jeep, often having untrained assistants to do the actual collecting of specimens to be pressed; they cannot recognise the species gathered in the field, so are blissfully unaware of their abundance or rarity either in the immediate vicinity or the district as a whole, whilst it is the norm to make few, if any field notes beyond a basic location and at times, estimated elevation. Thus, the only populations of plants/species covered/found are those which inhabit such places, with an over-representation of cosmopolitan road-side 'weeds', missing species found on cliffs altogether and how often have Indian botanists actually trekked? Seldom would be a fair description, giving a skewed impression of the flora. In comparison, Chris Chadwell, right from his early expeditions, could recognise the genus to which the majority of plants belong to in the Indian NW Himalaya above 2000m, albeit concentrating those which are ornamental merit and often not covering at all those of 'weedy' appearance or with insignificant/small flowers such as Poaceae (the grasses), Cyperaceae (the sedges) etc. - though Indian botanists are often guilty of this as well.
Others, such as Czech plant geographers have gone even further in Ladakh, prominent amongst them being the late Leos Klimes (who sadly went missing in Ladakh or possibly Kashmir) whose field botany skills were unrivalled in the borderlands of Western Tibet. Following on from him, other Czech scientists explored to the upper limits of flowering plants in Ladakh, discovering genuinely new species to science - no Indian botanist has ever scaled such heights. In 2018 Czech botanists (aided by German plant taxonomist Dickore) have published the welcome, 'A Field Guide to the Flora of Ladakh' (which was based upon a check-list of Ladakh plants published by Klimes & Dickore in 2005, whilst Chris Chadwell is due to complete the first part of his series of digital photographic guides to the Wild Flowers of Ladakh, Kashmir, Lahaul & Himachal Pradesh (covering genera A&B). The only thing India botanists have published about Ladakh plants is a very poor miniature book decades ago. Chris approached the then Director-General of the Botanical Survey of India in the mid-1980s, suggesting he collaborate with Indian botanists on an up-to-date Flora for Ladakh. He was told this was for Indian botanists to do - well, 30+ years later, no sign of such a flora. Within two years, Chris is going to publish (in the form of CDs) an up-to-date flora, sharing what photographic images he has available. Nowadays, photos are so much useful than detailed written description for the vast majority of people. Are foreign scientists "showing up" the Botanical Survey of India? Perhaps this is one of the reasons why they have introduced such draconian measures - not, as they claim, in the interests of conservation but as a smoke-screen to protect their shortcomings and failure to address the factors which are damaging the environment.