All of the new Meredithia species share with the generitype a similar appearance (at least in early stages), prostrate semipeltate to peltate blades with some species affixing ventrally to the substratum by secondary haptera. Only one species in the expanded genus, M. crenata, develops beyond this generic blade form with its clearly branched, strap-shaped habit. None of the species of Meredithia are particularly similar to the overall erect habit of the generitype of Psaromenia that is characterized by large
erect, simple to densely lobate blades (Table 2). Many of our Meredithia specimens (most commonly in M. crenata and M. pseudopeltata, but to a lesser degree in all the species) produce stipes from blades margins (e.g., stalked blades produced from stalked blades; Fig. 4G), a feature not AG-014699 supplier seen thus far in Psaromenia. Whether these vegetative characteristics constitute generic distinctions remains debatable. Psaromenia berggrenii was shown to be both moncarpogonial and polycarpogonial (D’Archino et al. 2010), while thus far Meredithia has
only been demonstrated to be monocarpogonial (Table 2; Guiry and Maggs 1984). As discussed above, our molecular evidence for these two genera shows a separation of two monophyletic clades that could be construed at the generic level or simply as variation among species in a larger and more diverse, monophyletic Meredithia (Figs. 1 and 2). For the present, and bolstered by our morphological study, we choose to continue to recognize both Meredithia and Psaromenia awaiting further genetic selleck chemicals data on additional species within
the Kallymeniaceae to allow see more for a more informed assessment of generic relationships. The specimens in our phylogenetic trees labeled as Psaromenia sp.1Jeju (Fig. 8) consist of lobed or branched erect blades with simple stalks and they group with P. berggrenii in our molecular analysis (Fig. 2). This molecular species is morphologically similar to Korean populations attributed to the South African Pugetia harveyana (J. Agardh) R.E. Norris (Lee et al. 2005, Lee 2008, both as K. harveyana J. Agardh). Norris (1964) moved K. harveyana to Pugetia without a clear explanation, but presumably because it lacked a “primarily produced filamentous medulla” as was pointed out in the same paper for another species he moved to the genus, P. porphyroidea (F. Schmitz ex Holmes) R.E. Norris. In any case, Clarkston and Saunders (2012) raised questions about the generic placement of both species, but did not have South African material to sequence. The Jeju specimens have huge stellate medullary ganglia and a filamentous medulla, similar to the illustrated cross-sections of previously studied Korean plants (Lee et al. 2005), features not described or illustrated in the South African specimens (Norris 1964). Both characteristics are typical for a number of genera in the Kallymeniaceae, but not for Pugetia (Clarkston and Saunders 2012). By looking at the lectotype of P.