Electronic Flora of South Australia Genus Fact Sheet

Genus CRYPTONEMIA J. Agardh 1842: 100

Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Halymeniaceae

Thallus foliose or with flattened, often crispate, blades, usually with a basal, cartilaginous, branched, perennial stalk (often derived from the midrib). Structure multiaxial, developing a relatively thin cortex and medulla of entwined filaments; refractive ganglionic cells present.

Reproduction: Sexual thalli usually dioecious. Carpogonial branch ampullae relatively simple with few secondary filaments. Auxiliary cell ampullae larger, with numerous secondary filaments, converging above. Carposporophyte of densely aggregated carposporangia, with a basal auxiliary cell, slight involucre, and small ostiole. Spermatangia cut off from outer cortical layer.

Tetrasporangia scattered in outer cortex which usually proliferates slightly to form irregular filaments 2–3 cells long, cruciately divided.

Life history triphasic with isomorphic gametophytes and tetrasporophytes.

Lectotype species: C. lactuca (C. Agardh) J. Agardh 1842: 100 [= C. lomation (Bertoloni) J. Agardh 1851: 227].

Taxonomic notes: A genus of some 30 species, widespread in tropical and temperate seas, with one common species and two rare species in southern Australia, a further species in Western Australia and just reaching southern Australia, and another on SE Australian coasts.

References:

AGARDH, J.G. (1842). Algae Maris Mediterranei et Adriatici, Observationes in Diagnosin Specierum et Dispositionem Generum. (Fortin, Masson: Paris.)

AGARDH, J.G. (1851). Species Genera et Ordines Algarum. Vol. 2, Part 1, 1–336 + index. (Gleerup: Lund.)

The Marine Benthic Flora of Southern Australia Part IIIA complete list of references.

Author: H.B.S. Womersley & J.A. Lewis

Publication: Womersley, H.B.S. (14 January, 1994)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIIA, Bangiophyceae and Florideophyceae (to Gigartinales)
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIIA 1994, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.

KEY TO SPECIES OF CRYPTONEMIA

1. Basal stalk slight, not extending into the blades

2

1. Basal stalk thick and prominent, often extending into the blades as a midrib

3

2. Thallus sparsely branched, branches with slender bases, 5–15 (–40) mm broad above, then tapering to the apices

C. wilsonii

2. Thallus frequently and subdichotomously branched, branches linear, 5–10 mm broad, with rounded apices

C. digitata

3. Blades undulate, 5–10 mm broad, of fairly uniform width with a well developed midrib becoming denuded below

C. undulata

3. Blades flat and smooth, tapering above or foliose, arising from the apex of branched, cartilaginous, basal stalks

4

4. Basal stalk coarse, 4–10 (–20) mm thick, bearing foliose blades with indented lobes, 5–30 cm broad; outer cortical cells not tapering outwardly

C. kallymenioides

4. Basal stalk slender, 1–2 mm in diameter, bearing branched blades mostly 4–10 mm broad; outer cortical cells tapering outwardly

C. nitophylloides


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