Belongs within: Laminariales.
The Lessoniaceae are a clade of large kelps in which specialised sporophylls are absent or borne on blades arising from the transition zone.
<==Lessoniaceae
|--Eckloniopsis Okamura 1927SRR14
|--Eisenia Areschoug 1876SRR14
| `--E. arborea Areschoug 1876AH76
|--Egregia Areschoug 1876SRR14
| |--*E. menziesii (Turner) Areschoug 1876AH76 (see below for synonymy)
| `--E. laevigata Setchell 1896N10
|--Lessonia Bory de Saint-Vincent in Dumont d’Urville 1825SRR14
| |--L. brevifolia Agardh 1894L27
| |--L. fuscescensBS-V28
| |--L. nigrescens Bory 1825GO78 [=Laminaria nigrescensBS-V28]
| |--L. quercifolia Bory de Saint-Vincent 1828B28
| `--L. variegata Agardh 1877L27
`--Ecklonia Hornemann 1828SRR14
|--E. brevipes Agardh 1877L27
|--E. buccinalis (Linnaeus) Hornemann 1828L27
|--E. cavaKM03
|--E. maximaPA03
|--E. radiata (Turner) Agardh 1848L27
| |--E. r. var. radiataL27
| |--E. r. var. exasperata (Turner) Agardh 1848L27
| |--E. r. var. flabelliformis Agardh 1848L27
| `--E. r. var. richardiana Agardh 1848L27
`--E. stoloniferaHS98
*Egregia menziesii (Turner) Areschoug 1876AH76 [=Fucus menziesii Turner 1808AH76, Phyllospora menziesii; incl. Egregia laevigata f. borealis Setchell 1925AH76, E. laevigata ssp. borealis (Setchell) Silva 1957, E. menziesii ssp. insularis Silva 1957AH76, E. planifolia Chapman 1962AH76]
*Type species of generic name indicated
References
[AH76] Abbott, I. A., & G. J. Hollenberg. 1976. Marine Algae of California. Stanford University Press.
[BS-V28] Bory de Saint-Vincent, J. B. 1828. Voyage Autour du Monde, Exécuté par Ordre du Roi, Sur la Corvette de Sa Majesté, La Coquille, pendant les années 1822, 1823, 1824 et 1825. Botanique. Cryptogamie. Arthus Bertrand: Paris.
[GO78] Gallardo S., C., & C. Osorio R. 1978. Hiatella solida (Sowerby, 1834) (Mollusca: Hiatellidae) on Concholepas concholepas (Bruguière, 1789) and other substrates. Veliger 20 (3): 274–278.
[HS98] Hara, I., & T. Sakurai. 1998. Isolation and characterization of vanadium bromoperoxidase from a marine macroalga, Ecklonia stolonifera. Journal of Inorganic Biochemistry 72: 23–28.
[KM03] Kawai, H., S. Maeba, H. Sasaki, K. Okuda & E. C. Henry. 2003. Schizocladia ischiensis: a new filamentous marine chromophyte belonging to a new class, Schizocladiophyceae. Protist 154: 211–228.
[L27] Laing, R. M. 1927. A reference list of New Zealand marine algae. Transactions and Proceedings of the New Zealand Institute 57: 126–185.
[N10] Norris, J. N. 2010. Marine algae of the northern Gulf of California: Chlorophyta and Phaeophyceae. Smithsonian Contributions to Botany 94: 1–276.
[PA03] Pfister, C. A., & K. L. van Alstyne. 2003. An experimental assessment of the effects of nutrient enhancement of the intertidal kelp Hedophyllum sessile (Laminariales, Phaeophyceae). Journal of Phycology 39: 285–290.
[SRR14] Silberfeld, T., F. Rousseau & B. de Reviers. 2014. An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie, Algologie 35 (2): 117–156.