A Comparison ofSenecio kirkii(New Zealand) andSenecio insularis(Lord Howe Island) with Senecios Endemic to the Island of St Helena

Abstract

The mutual relationships of four similar shrubby forest Senecios inhabiting three warm southern oceanic islands are assessed using morphological and anatomical features of flowers, involucral bracts, and leaves. It is shown that S. kirkii is about the same phenetic distance from S. insularis as it is from S. prenanthiflorus, which in turn is about the same distance from S. leucadendron. The greatest phenetic distances involved are those between S. leucadendron and S. kirkii and S. insularis. The nomenclatural implications are discussed. It is also noted that several floral characters anomalous in Senecio are concurrent in these species, and that three of them exhibit almost identical petiole and leaf blade anatomy.