Parenchymatous, with growth from an apical cell

Branching monopodal, with lateral branch systems consisting of leaf-like blades, air bladders, and recepticles

Haploid generation reduced to the egg and sperm

Gametes retained in conceptacles

Gamete union is oogamous

(Lee, 1999; Graham & Wilcox, 2000).

The Sargussum of the Sargasso Sea never develop holdfasts, and all reproduction is vegetative (Graham & Wilcox, 2000).