About
Contact
Links
Electronic Flora of South Australia
Electronic Flora of South Australia
Census of SA Plants, Algae & Fungi
Identification tools
 

Electronic Flora of South Australia Species Fact Sheet

Polysiphonia haplodasyae Womersley 1979: 465, fig. 1A–D.

Phylum Rhodophyta – Family Rhodomelaceae – Tribe Polysiphonieae

Thallus (Fig. 77A) brown-red, 0.5–1.5 (–2) mm high, forming minute, densely branched tufts; epiphytic on Haplodasya urceolata. Structure. Basal attachment by a cellular disc on the corticated axes of Haplodasya, with elongate cells of epiphyte and host cells intermingling, but without distinct rhizoids; erect axis from the basal attachment short, 100–150 (–300) µm in diameter with segments L/D 0.5–0.7, branching every few segments with mid branches 70–100 (–200) µm in diameter with segments L/D 0.5–0.75 (–1), tapering to 30–60 µm in diameter and segments L/D 0.3–0.5 shortly below the straight apices; trichoblasts occasional to profuse; lateral branches replacing trichoblasts, cicatrigenous branches absent. Pericentral cells 4, L/D 1–1.5 (–2) (Fig. 77D), ecorticate except for slight cortication by odd cells near the base; trichoblasts (Fig. 77D) formed on every segment, with a divergence of i/4, relatively robust and 12–25 µm in diameter in lower cells, simple to 3 times furcate, scar cells prominent, round in surface view. Rhodoplasts discoid, scattered.

Reproduction: Gametophytes dioecious. Carposporophyte with a small basal fusion cell and branched gonimoblast with clavate terminal carposporangia 15–20 µm in diameter. Cystocarps (Fig. 77A, B) short stalked, globular to ovoid, not or slightly urceolate, 150–300 (–400) µm in diameter; pericarp 2 cells thick, with enlarged ostiolar cells, outer cells isodiametric, angular. Spermatangial branches (Fig. 77C) developing as one basal branch of a trichoblast, elongate-ovoid to gently tapering from the base, 80–130 µm long and 35–60 µm in diameter, without or with a prominent sterile apical cell when mature.

Tetrasporangia (Fig. 77D) formed in spiral series in branches, usually extending below 1–3 branchings, slightly to moderately distorting the branch, subspherical to ovoid, 25–60 µm in diameter.

Type from Pennington Bay, – Kangaroo I., S. Aust., epiphytic on Haplodasya urceolata (Harvey) Parsons, on Cystophora intermedia J. Agardh, sublittoral fringe (Parsons, 17.xi.1967); holotype in AD, A31892.

Selected specimens: (All on Haplodasya urceolata). The type; Pennington Bay, Kangaroo I., S. Aust., sublittoral fringe (Mitchell, 20.viii.1963; AD, A26993) and (Womersley, 19.i.1965; AD, A28922). Bales Beach, Kangaroo I., S. Aust., drift (Womersley, 29.xii.1999; AD, A68436).


Distribution map based
on current data relating to
specimens held in the
State Herbarium of SA

Distribution: Only known froth the south coast of Kangaroo I., S. Australia.

Taxonomic notes: coast of Kangaroo I., shoes all the essential characters of Polysiphonia. It is radially branched This minute species, only known as an epiphyte on Haplodasya urceolata on the south at the apices, with exogenous apical branching, and has the normal occurrence of reproductive organs for the genus. Amongst southern Australian species, it is unusual in having a pad of cells as the attachment organ rather than distinct elongate rhizoids. Each plant of Haplodasya bore numerous plants of the Polysiphonia, virtually all of which were fertile.

References:

WOMERSLEY, H.B.S. (1979). Southern Australian species of Polysiphonia Greville (Rhodophyta). Aust. J. Bot. 27, 459–528.

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

Publication: Womersley, H.B.S. (24 February, 2003)
The Marine Benthic Flora of Southern Australia
Rhodophyta. Part IIID. Ceramiales – Delesseriaceae, Sarcomeniaceae, Rhodomelaceae
Reproduced with permission from The Marine Benthic Flora of Southern Australia Part IIID 2003, by H.B.S. Womersley. Australian Biological Resources Study, Canberra. Copyright Commonwealth of Australia.


Illustration in Womersley Part IIIA, 2003: FIG. 77 A–D.

Figure 77 image

Figure 77   enlarge

Fig. 77. A–D. Polysiphonia haplodasyae (A, B, D, AD, A3I892; C, AD, A68436). A. A complete cystocarpic plant. B. Immature and mature cystocarps. C. Spermatangial branches (young?). D. A tetrasporangial plant. E–H. Polysiphonia shepherdii (AD, A33838). E. Habit. F. Branches with cystocarps. G. Median view of mature cystocarp. H. Tetrasporangial branches. (All as in Womersley 1979, courtesy of Aust. J. Bot.)


Disclaimer Copyright Disclaimer Copyright Email Contact:
State Herbarium of South Australia
Government of South Australia Government of South Australia Government of South Australia Department for Environment and Water