An historical review and new taxa in the Madeiran endemic genusMonizia(Apiaceae, Apioideae)

Abstract

The monotypic genus Monizia (Apiaceae) endemic to Madeira was published by Richard Thomas Lowe in 1856. Several authors have considered different taxonomic arrangements either by merging the genus with Thapsia or with Melanoselinum. Recent molecular data suggested a clear-cut separation of both Monizia and Melanoselinum from Thapsia but also from Tornabenea, a genus that is endemic to the Cape Verde Islands. The genus Monizia was initially recorded on one single island of the archipelago of Madeira; it was later reported on two other islands of the same archipelago and also in the Selvagens archipelago. Only recently, Monizia was found to occur on one of the islets of Porto Santo. In the present work, Monizia is retained as a monotypic genus and four subspecies of Monizia edulis are described and illustrated, based on morphological traits: two on the island of Madeira, namely M. edulis subsp. isambertoi and M. edulis subsp. giranus; one on Deserta Grande, namely M. edulis subsp. edulis; and one on Porto Santo, namely M. edulis subsp. santosii. These new taxa are distinguished in generic terms by their differences in stem and umbel length, the degree of division of the radical leaves and arrangement of ultimate segments, dimensions of calyx teeth, style orientation and length, mericarp size and shape, mericarp texture, and mericarp rib size and shape. Typification of the genus Monizia, its species and subspecies, descriptions, present-day geographical distribution, habitats, conservation status, synonymy and a comprehensive key to the new taxa are presented and discussed.