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Electronic Flora of South Australia Family Fact Sheet
Phylum Rhodophyta – Order Ceramiales – Family Ceramiaceae
Thallus erect, usually pinnate, complanately and distichously branched, laterals alternate or opposite, branches compressed. Structure. Apices with oblique cross walls, subapical cells cutting off cells alternately or oppositely, if opposite then developing equally or one (alternately) more so than the other; cortication usually commencing close to apices, pseudoparenchymatous, becoming several cells thick, outer cells small, compact and isodiametric, with the axial filament remaining as a large central cell. Cells uninucleate or multinucleate.
Reproduction: Gametophytes dioecious. Procarps borne on ecorticate laterals close to apices, with 2–4 periaxial cells, one (the supporting cell) bearing a 4-celled carpogonial branch; auxiliary cell developing a foot cell and upper gonimoblast cell producing 1–3 successive rounded gonimolobes, the carposporophyte becoming surrounded by involucral branchlets from the sterile procarp cells or from below the procarps. Spermatangia in dense clusters on the pinnules or covering them on all sides.
Tetrasporangia sessile or pedicellate on the ultimate ecorticate branchlets, or on 1–3 celled pedicels arising on the outer cortical cells of laterals; parasporangia present in some taxa, clustered, terminal on branchlets.
Life history triphasic, with isomorphic gametophytes and tetrasporophytes.
Type genus: Ptilota C. Agardh 1817, pp. xix, 39, nom. cons.
Taxonomic notes: The tribe includes some 8 genera, characterised by the complanate, distichous and alternate or opposite branching, with apical cells dividing usually obliquely, dense cortication commencing close to the ecorticate apices and with compact, short, outer cells, carposporophytes with involucral filaments from the sterile procarp cells or from lower segments, and tetrasporangia borne on ecorticate filaments.
All Australian species need detailed study as to whether they satisfactorily agree with concepts of the tribe.
References:
AGARDH, C.A. (1817). Synopsis Algarum Scandinaviae. (Berling: Lund.)
CRAMER, C. (1863). Physiologisch-systematische Untersuchungen fiber die Ceramiaceen. Neue Denkschr. Aug.l Schweiz. Ges. Naturwiss. 20, i-iv, 1–131, Plates 1–13.
The Marine Benthic Flora of Southern Australia Part IIIC complete list of references.
Publication:
Womersley, H.B.S. (24 December, 1998)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIC. Ceramiales – Ceramiaceae, Dasyaceae
©State Herbarium of South Australia, Government of South Australia
KEY TO GENERA OF PTILOTEAE
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1. Subapical cells producing laterals alternately on successive cells, cortication commencing | EUPTILOTA |
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1. Subapical cells producing 2 or 4 opposite laterals but with one of each pair alternately better developed | 2 |
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2. Apices overtopped by ecorticate, curved, alternately branched, pinnate to bipinnate laterals | "PTILOTA" hannafordii |
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2. Apices not overtopped by ecorticate laterals, cortication commencing very close to apices | DIAPSE |
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Email Contact: State Herbarium of South Australia |
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