Electronic Flora of South Australia Genus Fact Sheet

Genus CRASPEDOCARPUS Schmitz in Schmitz & Hauptfleisch 1897: 375

Phylum Rhodophyta – Class Florideophyceae – Order Gigartinales – Family Cystocloniaceae

Thallus complanately and irregularly to subdichotomously marginally branched, branches flat, margin smooth or proliferous; holdfast discoid. Structure uniaxial, usually with a slightly projecting apical cell, the axial and periaxial filaments usually visible when stained; medulla slight, with some rhizoidal filaments, cortex 1–2 (–4) cells thick, with well-developed rosettes of small outer cortical cells around the larger inner cells; gland cells absent.

Reproduction: Sexual thalli dioecious; procarpic. Carpogonial branches 3 (–4)-celled, borne on inner cortical cells, laterally directed with slightly reflexed trichogynes, with the auxiliary cell adjacent to the supporting cell, becoming darkly staining as do nearby cells which produce a small-celled nutritive tissue inwards to the auxiliary cell. Carposporophytes with several large central cells and radiating gonimoblast filaments bearing terminal chains of carposporangia, with a few sterile filaments joining with the pericarp; cystocarps protuberant, marginal or scattered, with a pericarp, non-ostiolate. Spermatangia scattered, cut off from rosette cells.

Tetrasporangia in the outer cortex, scattered, zonately divided.

Life history triphasic with isomorphic gametophytes and tetrasporophytes.

Type species: C. erosus (Hooker & Harvey) Schmitz in Schmitz & Hauptfleisch 1897: 375, from New Zealand.

Taxonomic notes: A genus of seven species the type from New Zealand, four species from southern Australia and two from North Carolina and Brazil (Schneider 1988).

Craspedocarpus is closely related to Rhodophyllis, differing in having several large central cells rather than a fusion cell in the carposporophyte, and in having more distinct rosettes in the cortical cells (usually two or more cells broad).

References:

SCHMITZ, F. & HAUPTFLEISCH, P. (1897). Gelidiaceae, Acrotylaceae, Gigartinaceae, Rhodophyllidaceae, Sphaerococcaceae, Rhodymeniaceae, pp. 340–405, Grateloupiaceae, Dumontiaceae, Nemastomaceae, Rhizophyllidaceae, Squamariaceae, pp. 508–537. In Engler, A. & Prantl, K., Die nattirlichen Pflanzenfamilien. T. 1. Abt. 2. (Engelmann: Leipzig.)

SCHNEIDER, C.W. (1988). Craspedocarpus humilis sp. nov. (Cystocloniaceae, Gigartinales) from North Carolina, and a reappraisal of the genus. Phycologia 27, 1–9.

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

Author: 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 CRASPEDOCARPUS

1. Thallus of similar width (4–7 mm) throughout, the margins bearing short (about 1–2 mm long), regularly arranged, unbranched, terete proliferations which become reproductive

C. blepharicarpus

1. Thallus tapering from base to apices or with basally constricted branches, margins without proliferations or with irregular, flattened, often branched ones usually over 2 mm long

2

2. Thallus usually under 10 (–15) cm high, branches 2–5 mm broad, with no or few proliferations, branches tapering only slightly and often basally constricted

C. venosus

2. Thallus commonly over 10 cm high with lower parts 4–20 mm broad, usually with numerous, irregular, branched proliferations

3

3. Thallus membranous, usually 172 mm broad near apices, margins with numerous proliferations; rosette cells closely adjacent, usually with one or more cells cut off towards the rosette centre

C. ramentaceus

3. Thallus not membranous, strongly adherent to paper and often disintegrating on soaking, usually tapering to fine elongate apices less than 0.5 mm broad, margins with fewer, small proliferations; rosette cells rounded, often widely spaced, only dividing further in older parts

C. tenuifolius


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