Do Hydatellaceae belong to the monocotyledons or basal angiosperms? Evidence from seedling morphology.

Molecular phylogenetics of Hydatellaceae (Nymphaeales): Sexual‐system homoplasy and a new sectional classification

“…The morphological differences between unisexual RUs ( Table 1 , Fig. 4 ) ( Sokoloff et al, 2008a ) is analogous to differences seen between fl ower types in some dioecious species ( Eckhart, 1999 ) and is consistent with sexual specialization in the functions of while members of sections Trithuria and Hydatella possess a cotyledonary sheath ( Tillich et al, 2007 ;Sokoloff et al, 2008b ). Unfortunately, we currently lack data on seedlings in section Altofi nia .…”

“…Sokoloff et al (2008a) compiled a list of characters of potential taxonomic and evolutionary interest for the family. We completed this data set by fi lling in character states for Trithuria konkanensis from the literature ( Yadav and Janarthanam, 1994 ;Gaikwad and Yadav, 2003 ;Sokoloff et al, 2010 ), and by fi lling in missing character states of other species for seed cuticle , pericarp epicuticular wax ( Tillich et al, 2007 ;D. D. Sokoloff et al, unpublished data), pericarp anatomy (D. D. Sokoloff et al, unpublished data), and leaf auricles ( Rudall et al, 2007 ).…”

Shoot Architecture and Branching Pattern in Perennial Hydatellaceae (Nymphaeales)

“…Inclusion of Hydatellaceae in the basal grade of angiosperms (the ANA or ANITA grade) has greatly increased the significance of this small family in comparative studies of early angiosperm evolution. Recent investigations of Hydatellaceae have included the structure and development of the reproductive units (RUs; Rudall et al 2007Rudall et al , 2009, embryology (Friedman 2008;Rudall et al 2008), seedling morphology (Tillich et al 2007;Sokoloff et al 2008b), fruit morphology (Rudall et al 2007;Sokoloff et al 2008a), palynology , and tracheid structure (Carlquist and Schneider 2009). …”

Embryology in Trithuria submersa (Hydatellaceae) and relationships between embryo, endosperm, and perisperm in early‐diverging flowering plants

“…In the 5 years since members of the Hydatellaceae vaulted from the relative obscurity of the Poales to the stardom of the ancient angiosperm lineage Nymphaeales (Saarela et al, 2007), much work has been focused on the structural and reproductive biology of this unusual and important clade of plants (Rudall et al, 2007, 2008, 2009a, 2009b; Tillich et al, 2007; Friedman, 2008; Remizowa et al, 2008; Sokoloff et al, 2008a, 2008b, 2009, 2010, 2011; Carlquist and Schneider, 2009; Tratt et al, 2009; Taylor et al, 2010; Tuckett et al, 2010a, 2010b; Prychid et al, 2011; Taylor and Williams, 2012; Iles et al, 2012). We now know that members of the Hydatellaceae represent an extraordinary clade of miniscule wind‐ or water‐pollinated water lilies, whose highly peculiar reduced morphology and somewhat unusual reproductive biology present many difficulties in assessing homologies and reconstructing evolutionary history.…”

“…Considerable study has been focused on the reproductive “units” of the Hydatellaceae and whether they represent inflorescences with small unisexual flowers that lack a perianth or a form of transitional protoflowers (Rudall et al, 2007, 2009a, 2009b; Saarela et al, 2007; Endress and Doyle, 2009; Sokoloff et al, 2009, 2010). The development of the seedlings has also been examined but with differing conclusions as to the number of cotyledons present (one or two) (Tillich et al, 2007; Sokoloff et al, 2008b; Rudall et al, 2009b). Yet, for all of the complexities of understanding the morphology of Hydatellaceae, members of this clade bear the unmistakable and unique embryological signature of the Nymphaeales.…”