Electronic Flora of South Australia Genus Fact Sheet

Genus CAMONTAGNEA Pujals 1981: 14

Phylum Rhodophyta – Class Florideophyceae – Order Acrochaetiales – Family Acrochaetiaceae

Thallus 5–20 cm high, fastigiate and much branched, with uniseriate indeterminate axes of large cells and large, terminally rounded, apical cells, with determinate branchlets arising laterally or from a dense covering of rhizoids around the axes, with acute apical cells and several subapical cells bearing unilaterally short 1 (–2)-celled spines; holdfast fibrous. Cells with a central suspended nucleus with a prominent nucleolus and parietal rhodoplasts which are ribbon like (with several pyrenoids) in the subapical cell, becoming numerous, stellate and lobed, with a central pyrenoid in the other cells; pit-plugs domed on either side of the pit.

Reproduction: Only tetrasporangia known (in the type species), borne on short branched laterals on lower cells of upper branches, subspherical, irregularly cruciately divided.

Life history unknown.

Type species: Camontagnea oxyclada (Montagne) Pujals 1981: 15.

Taxonomic notes: Camontagnea is based on the taxon commonly known as Ballia scoparia (Hooker & Harvey) Harvey and placed in the Ceramiaceae. Wollaston (1968, p. 320) considered that it should probably be excluded from Ballia, and Pujals (1981, p. 6, figs 24, 25, 28) showed that the stellate, lobed, rhodoplasts contain a central pyrenoid, thus excluding it from the Ceramiaceae. Pujals found the oldest specific name to be Conferva oxyclada Montagne (1839, p. 5) and suggested that the genus be placed in the Acrochaetiales, related to Rhodochorton (as Audouinella floridula above).

This re-positioning is accepted pending further studies on the life history and ultrastructure, and Ballia hirsuta Wollaston is also transferred to Camontagnea. Camontagnea differs from other genera of the Acrochaetiaceae (however many are accepted) by its much greater size and cell diameters, by the presence of indeterminate axes with terminally rounded apical cells and determinate laterals with acute apical cells and short spines on 1–5 subapical cells. However, the stellate rhodoplasts each with a central pyrenoid are similar to those of Audouinella floridula and A. caespitosa.

References:

MONTAGNE, C. (1839). Cryptogames de la Patagonie. In D'Orbigny, A., Voyage dans l'Amérique Méridionale ... pendant ... 1826–1833. Vol. 7. Bot., Part I. Sertum patagonicum, pp. 1–19, Plates 1–4. (Paris.)

PUJALS, C. (1981). Identidad de "Ballia scoparia" (Hook.f. et Harv.)Harv. (Rhodophyta, Florideophycidae). Rev. Mus. Arg. Cienc. Nat. "B. Rivadavia", Bot. 6, 1–22.

WOLLASTON, E.M. (1968). Morphology and taxonomy of southern Australian genera of Crouanieae Schmitz (Ceramiaceae, Rhodophyta). Aust. J. Bot. 16, 217–417, Plates 1–10.

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

Author: W.J. Woelkerling & H.B.S. Womersley

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 CAMONTAGNEA

1. Thallus with numerous branches, distantly alternately branched, axes covered below with a felt of branched rhizoidal filaments not producing short outward branchlets

C. oxyclada

1. Thallus with several distinct axes densely covered with branched interwoven rhizoidal filaments producing a dense cover of short outward branchlets 2–3 mm long

C. hirsuta


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