This might be the reason why some submerged plants such as Utricularia vulgaris, Spirodela polyrhiza, Hydrocharis morsus-ranae, and Elodea canadensis present in the modern vegetation of L.
Decomposition is intensive for macrophytes with soft tissues such as Utricularia vulgaris, Spirodela polyrhiza, Hydrocharis morsus-ranae, and Elodea canadensis; so they are unlikely to be preserved as fossils.
In itself this is not a new topic: Miki (1937) speculated on the equivalence of the pla nt body in Najas to the stolon in Hydrocharis, and this type of consideration appeared again later, in Wilder (1975).
Known as American frogbit, this is a floating stoloniferous aquatic that, unlike its European counterpart, Hydrocharis norsus-ranae, does not form overwintering turions and therefore cannot survive in lakes that freeze during winter.
Coming back to the Hydrocharitaceae, a number of detailed analyses have been conducted of the architecture of the shoot system, particularly of freshwater representatives such as Limnobium, Hydrocharis, Elodea, Vallisneria, and Stratiotes (e.
In Hydrocharis, discounting events in the inflorescence proper, we concluded (Posluszny & Charlton, 1999) that there are basically two forms of axillary complex.
The archetypal inflorescence in Hydrocharitaceae seems to be a long internode surmounted by a terminal flower above two bracts, which probably subtend lateral structures (Kaul, 1970), while the stolon of Hydrocharis (Posluszny & Charlton, 1999), Limnobium (Wilder, I 974b), and Stratiotes.
We showed that, in the male inflorescences of Hydrocharis, the sequence of bifurcations that forms a cluster of flowers in the bract axils can be terminated by the formation of a stolon complex instead of a floral meristem and that a stolon complex can occur in the axil of the single bract of the female inflorescence.