Hello to everybody.
I would like to present my growing experiences about
Myriophyllum sp. "Roraima".
I had received this plant about 2 years ago from my friend Carmelo Lino Famà (Linus87 on the forum), one of the earlist people that introduced this specimen in Europe.
Initially, I planted it in a paludarium, where it was emersed quickly, and it passed the first cold season (minimum temperatures about 15° with artficial light). In this condition it grew very well, but I haven't observed flowers.
In the first spring I moved this emersed
Myriophyllum in an outdoor pond. This plant has seemed to have more green-yellowish leaves, a more frail feature and small size as compared with the
M. aquaticum. Under sun's light stems are reddish. This new watermilfoil tends to produce more secondary stems on principal ones in comparison with the
M. aquaticum.
In the second winter I wanted to test its cold-resistance. The result was very interesting: the plants were resistant to freezing and snow's covering without problems (minumum temperature of the air was -7 °C for some hours) and none of the leaves were damaged (which almost always occurs with typical
M. aquaticum in my garden). I'm in USDA Z8 B.
For these reasons I presume that
Myriophyllum sp. "Roraima" is a good hardy plant for garden's ponds.
Yesterday I obserbed a first flower at the moment.
It forms at axil of leaves, with a pedicel about 4-5 mm (at anthesis). I saw 4 white-greenish sepals, triangular and weakly denticulate, but I did not seen petals (maybe fallen?); 8 stamens were very visible.
From the above this flower seems a male's
Myriophyllum flower and its description is similar to
M. aquaticum's one.
And than I wanted to observe the center of the flower, moving the stamens, and I think to have see 4 structures similar to pistils. For this reason this flower seems bisexual.
When the plant will emit more flowers I will be able to observe it better with a binocular microscope.
I have consulted the bibliography regarding the
Myriophyllum aquaticum, and I have recognized the existence of dioeciuos, monoecious and polygamous (with bisexual flowers) specimens described in Brazil.
I will be grateful if you give me your opinion, thank you.
Roberto Pellegrini