BSBINews103

Notes - Time For Reflection I DNA Analysis - Some Queries I Hillier Herbarium 21species' sites accrued additions quickly andsmoothly on the second examination, like aconfident batsmen nearing his century. Many ofthese rich stretches did in fact exceed 100species in the end, without my exercising aparticular search- effort.In contrast, the lengths with fewer than 50species on the frrst visit tended to stay that way.This might have been predictable if they hadconsisted of, say, 500 metres of dense andmonocultural growth such as reed, Phragmitescommunis, but in only one case, so far as Irecall, did this condition occur, and then overonly part of the length. And it should be bornein mind that the surveys covered both banks and25 metres of 'Corridor' away from the river, soscope for diversity was not by any means limited.It may again seem to be stating the obvious,but at the time the discovery took me bysurprise; and the experience has been re-enacted,occasionally, since then. Repeat visits todiverse communities that had already shown animpressive species-list during previous surveysoften produced at least one or two additions.This happened even when the second look wasa casual encounter rather than 'official' andthorough field-work.DNA Analysis - Some QueriesALAN SHOWLER, 12 Wedgwood Drive, Hughenden Valley, High Wycombe, Bucks., HP 14 4PAI read (BSBI News 102: 69) that it has beendecided in the revision of Francis Rose's TheWihijlower Key to retain the old names for theorchids, rather than replace them with the new,DNA-derived names. I am sure this is best butequally sure that others will disagree! However,when the inter-relationship of only a relativelysmall number of our native plants has beeninvestigated by these techniques it would seemto me to be wise to wait a bit, otherwise wewould have a book in which some ofthe speciesare classified by their DNA and the remainderby structural features.As an organic chemist, inclining to biochemistry,I have some idea of the background tothese new techniques but it seems probable thatthe majority of our members will have little ideaof how these analyses are carried out (whichprobably does not matter), nor, and now Iinclude myself, how decisions are reached whenlooking at the results. My questions then - whatdecisions have to be made and how certain arewe of what is decided?All is based on the examination of a series ofbands, which can be converted to a series ofpeaks of varying intensities. But we are lookingat similarities and differences, so how differentis different? If two specimens are examined,what determines whether they are differentspecies, just subspecies or a single species ofdifferent races or origins? There must beborderline cases; if so do all the experts agree?I would welcome an article to tell us no morethan briefly how the analyses are carried out, butin more detail how decisions are reached.The Hillier Herbarium at Ampfield (Hampshire)ERlC J. CLEMENT, 54 Anglesey Road, Gosport, Hants. P012 2EQThe Sir Harold Hillier Gardens Herbarium is amajor new herbarium, with the acronym HILL,that was created in June 1995. With over 5000sheets it now features on the world wide web -see Index Herbariorum at The New YorkBotanic Garden site, NYBG.org. It representsthe work of a number of dedicated volunteers,including several BSBI members - a lot ofloving care has created some very beautiful (andscientifically valuable) pressed specimens. Itmostly features cultivated woody plants. but therich native and alien flora of the Gardens hasalso been sampled, and not only for vascularplants - Linda Barker (BSBI) et al. have addedin the bryophytes and lichens. David AlIen hasexpertly sampled the interesting Rubus flomla.The collection includes the official herbariumof the International Oak Society (IOS), hencethe 1750 sheets of Quercus (600 taxa). Thisexpresses the major interest of AlIen Coombes,Botanist, the BSBI referee for this genus.Dorothy Holley (lOS) has vigorously workedon the project since its inauguration and haspersuaded many souls (EJC included!) to helpout over the years.Many specimens have been collected outsideBritain, so it is an excellent venue to learnherbarium botany - some 212 families and 620genera of vascular plants are represented, allfiled in the standard, Bmmmitt order of Vascularplantfamilies andgenera(RBG,Kew, 1992).