The Cape Genus Lachnaea (Thymelaeaceae) A Monograph

About this book

The circumscription of Lachnaea L. (Thymelmaleae) is extended to include the five species previously placed in Cryptadenia Meisn. Four species and all varieties are reduced to synonymy; 12 species are newly described and one new name is proposed. Forty species and two subspecies are now recognized. No formal infrageneric groupings are upheld. Evidence from macromorphology, leaf anatomy, ecology and geographical distribution was used as basis for species delimitation. Palynology and chromosome numbers were found to be taxonomically insignificant at specific level. Two cladistic analyses show that Lachnaea is monophyletic and that previously proposed sections are paraphyletic. The two analyses produced mixed resolutions regarding the solitary-flowered species and gave conflicting results with regard to the evolutionary pathway of certain characters. Allopatric speciation appears to have been the dominant process in the evolution of Lachnaea. Additional variables that may have governed diversification are altitudinal difference, allochrony and post-fire regeneration strategies.

Lachnaea is endemic to the Cape Floristic Region and occurs almost exclusively in fynbos vegetation. The highest concentration of species (24) is found in the 3319 (Worcester) grid.

The taxonomic treatment includes a brief history of Lachnaea, keys to species and subspecies, detailed descriptions with notes on nomenclature, diagnostic features, relationships, distribution, ecology and conservation status. Line drawings and a distribution map are provided for each species.

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