Acrochaetiales

Acrochaetium secundatum, from here.

Belongs within: Florideophycidae.

The Acrochaetiales are a group of simple, filamentous red algae.

Characters (from Harper & Saunders 2002): Algae composed of monosiphonous simple or branched filaments, fitting one of the three following sets of characteristics: (1) marine; multiple parietal discoid to band-shaped plastids per cell, lacking pyrenoids; monosporangia unknown, reproducing primarily by asexual tetrasporangia; sexual life history, where known, biphasic with reduced gametophytes; (2) freshwater; cells possessing multiple parietal lobed to discoid plastids, lacking pyrenoids; reproducing primarily by monosporangia; sexual life history, where known, triphasic with morphologically similar gametophytes and tetrasporophytes; (3) marine; cells possessing a single axile stellate chloroplast, each with a single central pyrenoid; reproducing primarily by monosporangia; sexual life history, where known, triphasic.

Acrochaetiales [Acrochaetiaceae]
    |--Conchocelis rosea Batters 1892 S57
    |--Rhodochorton HS02
    |    |--*R. purpureum (Lightfoot) Rosenvinge 1900 (see below for synonymy) HS02
    |    |--R. penicilliforme (Kjellman) Rosenvinge 1894 S57
    |    |--R. purpureum (Lightfoot) Rosenvinge 1900 S57
    |    `--R. tenue Kylin 1925 S57
    |--Kylinia Rosenvinge 1909 S57, HS02
    |    |--*K. rosulata HS02
    |    |--K. arcuata (Drew) Kylin 1944 [=Chromastrum arcuatum, Rhodochorton arcuatum] S57
    |    |--K. hirsuta (Drew) Kylin 1944 [=Chromastrum hirsutum, Rhodochorton hirsutum] S57
    |    `--K. moniliformis (Rosenvinge) Kylin 1944 (see below for synonymy) S57
    |--Audouinella Bory de Saint-Vincent 1823 HS02
    |    |--*A. hermannii (Roth) Duby in de Candolle 1830 (see below for synonymy) HS02
    |    |--A. asparagopsis HS02
    |    |--A. membranacea (Magnus) Papenfuss 1945 [=Rhodochorton membranaceum] S57
    |    |--A. secundata HS02
    |    |--A. stricta HS02
    |    `--A. tenue HS02
    `--Acrochaetium Nägeli in Nägeli & Cramer 1858 [incl. Liagorophila Yamada 1944] HS02
         |--*A. secundatum (Lyngbye) Nägeli in Nägeli & Cramer 1858 (see below for synonymy) HS02
         |--A. arcuatum [=Audouinella arcuata] HS02
         |--A. daviesii HS02
         |--A. desmarestiae Kylin 1925 [=Rhodochorton desmarestiae] S57
         |--A. erythrophyllum Jao 1937 S57
         |--A. macounii (Collins) Hamel 1928 [=Chantrasia macounii, Rhodochorton macounii] S57
         |--A. pacificum Kylin 1925 [=Rhodochorton pacificum] S57
         |--A. subimmersum (Setchell & Gardner) Papenfuss 1945 [=Rhodochorton subimmersum] S57
         |--A. vagum (Drew) Jao 1937 [=Rhodochorton vagum] S57
         |--A. variabile (Drew) Smith 1944 [=Rhodochorton variabile] S57
         `--A. yamadae (Garbary) Harper & Saunders 2002 (see below for synonymy) HS02

Acrochaetium secundatum (Lyngbye) Nägeli in Nägeli & Cramer 1858 [=Callithamnion daviesii var. secundatum Lyngbye 1819, Colaconema secundata (Lyngbye) Woelkerling 1973] HS02

Acrochaetium yamadae (Garbary) Harper & Saunders 2002 [=*Liagorophila endophytica Yamada 1944, Audouinella yamadae Garbary 1980] HS02

*Audouinella hermannii (Roth) Duby in de Candolle 1830 [=Conferva hermannii Roth 1806, Chantransia hermannii (Roth) Desvaux 1809] HS02

Kylinia moniliformis (Rosenvinge) Kylin 1944 [=Chantrasia moniliformis, Chromastrum moniliforme, Rhodochorton moniliforme] S57

Rhodochorton purpureum (Lightfoot) Rosenvinge 1900 [=Byssus purpurea Lightfoot 1777, Audouinella purpurea (Lightfoot) Woelkerling 1973] HS02

*Type species of generic name indicated

REFERENCES

[HS02] Harper, J. T., & G. W. Saunders. 2002. A re-classification of the Acrochaetiales based on molecular and morphological data, and establishment of the Colaconematales ord. nov. (Florideophyceae, Rhodophyta). European Journal of Phycology 37: 463–476.

[S57] Scagel, R. F. 1957. An annotated list of the marine algae of British Columbia and northern Washington (including keys to genera). National Museum of Canada Bulletin 150: 1–289.