Henry Shejbal, Italy

to nomenclature problems

August 4, 2009
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Categories: Science, Standards, Taxonomy

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Dear All,

 Thanks for the answers to my message on the botanical families to which Narcissus is attributed by various institutions.

 An excellent explanation arrived from Dr. John David whom Brian kindly interpellated on this issue.

 Best regards

  Henry (Rome)

 Here is the answer:

 Dear Henry,

 Brian Duncan alerted me to your query on daffnet regarding the family to which Narcissus is assigned by various authorities. The situation with families, especially monocot families, has undergone quite a bit of change over the past few years, especially with the impact of DNA analysis. The three family names to which you found Narcissus to be placed under can be explained as follows:

 Liliaceae – this is the oldest placing and really there is no reason for putting Narcissus into this family at all. The members of the Liliaceae are fundamentally different to the amaryllids, but in the early part of the twentieth century there was a concept of a very broad family including most of the petaloid monocots, which has long been discarded.

 Amaryllidaceae – this is the traditional family for Narcissus and related genera.

 Alliaceae – a family initially formed for the onions and related genera, but molecular data have shown that members of the Alliaceae, Agapanthaceae and Amaryllidaceae share a common ancestor which is not shared by any other group. The classification based on molecular data (Angiosperm Phylogeny Group (APG II)) proposes that these three families should be treated as one because of this shared common ancestor and the oldest name for the family encompassing all three groups is Alliaceae. Recently that has been a proposal to make Amaryllidaceae the family name to be used for this larger grouping, on the grounds of the horticultural and economic significance of the members of the Amaryllidaceae, but it could also be argued that onions are also significant economically! These three families do share some basic characteristics, the inflorescences with subtending bracts (spathes) and the superior ovary are two in particular.

 For further information see: http://www.mobot.org/MOBOT/Research/APweb/welcome.html, and go to Asparagales, where you will find the three families treated together.

 The RHS accepts Amaryllidaceae and we are following as our standard David Mabberley’s Plant Book, 3rd Edition (2008). Professor Mabberley is Keeper of the Herbarium at Kew.

 In conclusion, the name to adopt depends upon whether you wish to follow the broader family concept and include the onions (Alliaceae), or the narrower concept which is well established in the literature of Amaryllidaceae.

 Regards,

 John David

 Dr John C David

Head of Botany

RHS Garden, Wisley

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