Belongs within: Fucophycidae.
The Ralfsiales are an order of brown algae that are crustose for at least part of their life cycle, with initial development being disc-shaped (Norris 2010).
Characters (Norris 2010): Crustose in at least one stage of life history or only in early stages of development. Initial development of thallus disc-shaped. Cells with one to several chloroplasts without pyrenoids. Unilocular sporangia (zoidangia) terminal or lateral, with or without paraphyses. Plurilocular sporangia (zoidangia) intercalary with terminal sterile cells.
Ralfsiales
|--Neoralfsia Lim & Kawai in Lim et al. 2007 [Neoralfsiaceae]SRR14
| `--N. expansa (Agardh) Lim & Kawai 2007HS14
|--MesosporaceaeSRR14
| |--Basispora John & Lawson 1974SRR14
| |--Hapalospongidion Saunders 1899 [=Hapalospongidium]SRR14
| | `--H. gelatinosum Saunders 1899 [incl. Microspongium saundersii Setchell & Gardner 1924]AH76
| `--Mesospora Weber-van Bosse 1911SRR14
| |--M. mediterraneaPP64
| `--M. schmidtiiK98
`--Ralfsiaceae [Heterochordariaceae]N10
|--Heteroralfsia Kawai 1989SRR14
|--Heterochordaria Setchell & Gardner 1924SRR14
|--Analipus Kjellman 1889SRR14, N10
| `--A. japonicus (Harvey) Wynne 1971 (see below for synonymy)AH76
|--Endoplura Hollenberg 1969N10
| `--E. aurea Hollenberg 1969AH76
`--Ralfsia Berkeley in Smith & Sowerby 1843N10
|--R. californica Setchell & Gardner 1924N10
|--R. confusa Hollenberg 1969N10
|--R. endopluroidesK98
|--R. expansa (Agardh) Agardh 1848N10
|--R. fungiformis (Gunnerus) Setchell & Gardner 1924 [=Fucus fungiformis Gunnerus 1766]AH76
|--R. hancockii Dawson 1944N10
|--R. hesperia Setchell & Gardner 1924N10
|--R. integra Hollenberg 1969AH76
|--R. pacifica Hollenberg in Smith 1944 [incl. R. occidentalis Hollenberg in Taylor 1945]N10
|--R. tenuis Kylin 1947K98
`--R. verrucosa (Areschough) Areschoug in Fries 1845N10 [=Cruoria verrucosa Areschough 1843N10; incl. R. deustaG64]
Analipus japonicus (Harvey) Wynne 1971 [=Halosaccion (Halocoelia) japonica Harvey 1857; incl. Chordaria abietina Farlow 1875, Heterochordaria abietina (Farlow) Setchell & Gardner 1924]AH76
*Type species of generic name indicated
References
[AH76] Abbott, I. A., & G. J. Hollenberg. 1976. Marine Algae of California. Stanford University Press.
[G64] Gray, J. E. 1864. Handbook of British Water-weeds or Algae. R. Hardwicke: London.
[HS14] Huisman, J. M., & A. Sampey. 2014. Kimberley marine biota. Historical data: marine plants. Records of the Western Australian Museum Supplement 84: 45–67.
[K98] Kaehler, S. 1998. The non-coralline epilithic encrusting algae of Hong Kong II: additions and identification. Asian Marine Biology 15: 1–17.
[N10] Norris, J. N. 2010. Marine algae of the northern Gulf of California: Chlorophyta and Phaeophyceae. Smithsonian Contributions to Botany 94: 1–276.
[PP64] Peres, J. M., & J. Picard. 1964. Nouveau manuel de bionomie benthique de la mer Mediterranee. Recueil des Travaux de la Station Marine d’Endoume, Bulletin 31 (27): 5–137.
[SRR14] Silberfeld, T., F. Rousseau & B. de Reviers. 2014. An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie, Algologie 35 (2): 117–156.