Consolea millspaughii

Three subspecies and data scope

POWO accepts the nominate C. millspaughii subsp. millspaughii, Cayman subsp. caymanensis and Florida subsp. corallicola. Each has its own profile, while this description covers the whole species. Papers preceding the rank change usually treat C. corallicola as a separate species. Reading these papers requires retaining their geographical and taxonomic scope. [2-WWW] [Korotkova et al. 2021]

As early as 2001, Areces-Mallea distinguished an informal C. millspaughii group linking these three taxa by closely spaced, sunken areoles and similar stem traits. Mature segment surfaces are not as distinctly reticulate as in Jamaican C. spinosissima. Within the group, trunk armature, flower size and shape and pericarpel structure differ. [Areces-Mallea 2001]

Relatedness, chromosomes and sex

The 2021 plastome study placed C. corallicola within the C. millspaughii lineage. The authors also noted morphological closeness and agreement in the observed ploidy level. Transfer to subspecies rank reflects this interpretation of relatedness. It does not mean Florida Keys populations are ecologically interchangeable with every Bahamian population. [Majure et al. 2021b] [Korotkova et al. 2021]

In C. millspaughii samples from Long Island in the Bahamas, 2n = 66 was counted. For subsp. caymanensis, DNA quantity suggested 8x, but no direct chromosome count was given. These results cannot be combined into one number characterising the whole current species without exception. [Negrón-Ortiz 2007, tab. 1, p. 1363]

Material identified as C. millspaughii was also examined in anther and ovule studies. In functionally female plants, lack of pollination could lead to later degeneration of unfertilised ovules. This differs from the loss of ovule function before flower opening characteristic of the male flowers examined. Assessing reproductive success therefore requires knowing developmental stage and pollen availability. [Strittmatter et al. 2006] [Strittmatter et al. 2008]