Phytologia (Aug 2004) 86(2) 55 



sequence data now provide statistically well-supported evidence of two 

 distinct major lineages. The name Rhipsalidoideae Burnett can be used 

 to recognize the clade containing most columnar cacti, epiphytes, and 

 globular cacti of South America (see Fig. 1). 



Molecular studies are rapidly increasing our recognition of 

 monophyletic lineages inthe Cactaceae facilitating improved classification 

 that reflects evolutionary relationships. Results of parsimony analysis 

 of more than 6,000 base pairs of chloroplast DNA sampled from 120 

 representative taxa across the family first revealed Blossfeldia as a 

 monophyletic lineage sister to the Cactoideae-Rhipsalidoideae clade 

 with strong bootstrap support (Crozier and Jansen, 2001). Nyfeller 

 (2002) independently inferred the same position of Blossfeldia rejecting 

 the possibility that this might be a taxon-sampling artifact (long-branch 

 attraction) in parsimony and maximum likelihood combined analysis of 

 trnK-matK and trnL-trnF data. Crozier et al. (2004 in prep.) compared 98 

 species of cacti, and outgroups from the Portulacaceae and Didieraceae 

 for 16,620 base pairs of chloroplast data using parsimony analysis that 

 yielded strong bootstrap support for the Blossfeldioideae as well (see Fig. 

 1 .). Furthermore, statistical support for this relationship of Blossfeldia 

 was 100% probable in a Bayesian analysis run for 4 million generations 

 of that combined data set representing 13 functional regions of the 

 chloroplast, including genes, introns and intergenic spacer regions. In 

 addition, Blossfeldia shares with the Pereskioideae, Opuntioideae and 

 Maihuenioideae unique chloroplast DNA motifs in multiple markers 

 (Crozier et al., 2004 in prep.). For this reason and its distinctive 

 morphology I am proposing to place Blossfeldia in its own subfamily. 



Blossfeldioideae Crozier, subfam. nov. 



Type: Blossfeldia Werd., Kakteenkunde 11:162(1937). 



Monotypic (1 species). Type species: B. liliputana Wcrd. 



Caudex crassus, caulis simplex dein proliferans, depresso-globosis 

 vel disciformibus 2.5 cm diametro vel parvioribus, neque costatis 

 neque tuberculatis vertice depress ioribus lanoso, sine hypodermata 

 epidermata una tabulato sine epicuticulo ceracea, parietibus cellularum 



