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Suffolk Natural History, Vol. 41 SUFFOLK RARE PLANT REGISTER
MARTIN SANFORD The publication of The Vascular Plant Red Data List of Great Britain (Cheffings & Farrell, 2005) in May has prompted this revision of the Suffolk Rare Plant Register. For the first time, all native and archaeophyte taxa have been analysed, not just those that had already been identified as rare or scarce. This analysis has been made possible by the publication of the New Atlas of the British and Irish Flora (Preston et al., 2002), which has allowed comparisons to be made with the Atlas of the British Flora (Perring & Walters, 1962) for all taxa. The new register follows guidelines on which species to include issued by the Botanical Society of the British Isles in June 2005. We are now able to include species which are rare in terms of their distribution (number of squares) and those which are declining. The new list therefore includes species which are both rare and declining (e.g. Creamflowered Marsh Orchid, Dactylorhiza incarnata subsp. ochroleuca) as well as species that are rare, but have stable populations (e.g. Blue Fescue, Festuca longifolia) and species that are widespread, but declining (e.g. Weasel’s-snout, Misopates orontium). The register includes all species occurring in Suffolk which are: 1. Internationally Rare - endemics and species listed in IUCN Red Lists, EU Habitats Directive or the Bern Convention 2. Nationally Threatened - All IUCN threat categories CR (critically endangered), EN (endangered), VU (vulnerable) and NT (near threatened) plus Nationally Rare (=RDB) - species occurring in less than 16 10-km squares in Britain (listed in Cheffings, 2004 with most described in Wigginton, 1999) 3. Nationally Scarce - species occurring in 16-100 10-km squares in Britain (listed in Cheffings, 2004 with most described in Stewart et al., 1994) 4. Locally Rare - species which are present in 3 sites or fewer 5. Locally Scarce and Declining - species that are present in 10 sites or fewer, or are thought to be in serious decline Recent extinctions of species in the above categories are also included, as are species in these categories which have only occurred as escapes or introductions and those which have both native and introduced populations. The list below is sorted by threat category and includes a few species from ‘Data deficient’, ‘Waiting’ and ‘Parking’ lists which may warrant inclusion on the basis of their status in Suffolk. Where the new status column still shows RDB (Nationally Rare) or Nationally Scarce it is because these species have been classed as ‘Least Concern’ in the IUCN national threat ratings; they are still significant as national rarities, but their populations are considered to be relatively stable. A few RDB and Nationally Scarce species have changed status and are now classed as neophytes (i.e. now not regarded as native), these have been included in the register with appropriate information in the comments. The ‘Suffolk Rarities’ in previous versions of the list equate to categories 4 and 5. Although these may be rated ‘Least Concern’ in a national context they
Trans. Suffolk Nat. Soc. 41 (2005)