[7] Unlike other Stramenopiles (heterokonts), their chloroplasts do not contain fucoxanthin, which accounts for their lighter colour.

[8] In 1899, Lüther created the group Heterokontae for green algae with unequal flagella.

These groups are called ambiregnal protists, as names for these have been published under either or both of the ICZN and the ICN.

Ultrastructural and molecular studies shows that the Mischococcales might be paraphyletic, and the Tribonematales and Botrydiales polyphyletic,[26] and suggests two orders at most be used until the relationships within the division are sorted.

[27] Informal groups, according to Maistro et al. (2009):[28] Unicellular flagellates, amoeboid and palmelloid taxa were not included in this study.