Ectocarpales

Ectocarpales is a very large order in the Phylum Phaeophyta or Brown algae. The order includes families with pseudoparenchymatous (Splachnidiaceae) or true parenchymatous (Scytosiphonaceae) tissue. Pseudoparenchymatous refers to a filamentous alga with cells packed very close together to give an appearance of parenchymatous tissue, the latter being composed of cells which can truly divide in three dimensions, unusual among the algae. Filamentous algae are composed of cells that divide along a single plane, allowing only elongation to form filaments of one or more rows of cells. Algae that can divide in two planes can form sheet-like thalli or bodies. Cells that can divide in a third plane potentially allow for the organism to develop a more complex body plan, and diversification of body plans into an erect thallus of some sort and a holdfast for attaching the upright portion to the substrate. The circumscription in the taxobox is from Lee.

AlgaeBase uses the following families for this order:


 * Acinetosporaceae Hamel ex J Feldmann
 * Adenocystaceae F Rousseau, B de Reviers, M-C Leclerc, A Asensi, and R Delépine
 * Chordariaceae Greville
 * Chordariopsidaceae Kylin
 * Ectocarpaceae C Agardh
 * Ishigeaceae Okamura
 * Mesosporaceae
 * Myrionemataceae Nägeli
 * Pylaiellaceae
 * Scytosiphonaceae Farlow

AlgaeBase places Ralfsiaceae in its own order, the Ralfsiales Nakamura, and Splachnidiaceae in the Scytothamnales AF Peters and MN Clayton.