These plants appear to be similar to if not identical with the small and scattered West Texas populations.

    We know that the northern populations of L. williamsii (including all of the known US populations and most probably the Coahuilan plants) are self-fertile. This means that they outcross very little and within a given population there is little to no genetic diversity among individuals.
    (Based on the preliminary DNA data published in Chapter IV of Dr. Terry's dissertation.)

These plants appear to be morphologically similar to if not identical with the South Texas populations.
    It is not known if these Tamaulipan plants are also similar to the South Texas plants in terms of their fertility (self-fertile) or if they are more like the El Huizache plants that known to be self-sterile (next image below) or if they lie somewhere in between.
    Their DNA can tell us the answer to this question.
    This underlines the need for a DNA-based genetic study across the geographic range of the genus.

Greenhouse breeding experiments by Bohata and colleagues in the Czech Republic and Koehres in Germany have shown that plants from this population are self-sterile and therefore obligate outcrossers (leading one to suspect a great deal of genetic diversity with many genotypes occurring in a single population).
    More images are on page 17 & 18.

These are more often solitary than offsetting. These love growing among rocks. They are found in mountainous terrain above a certain elevation but never on the lower slopes.

These are predominantly wildly caespitose and often form clumps of dozens of crowns.

L. koehresii's range overlaps L. williamsii range in part but it does not share the same habitat and instead prefers mud flats.