Electronic Flora of South Australia Species Fact Sheet

Nitospinosa littledipensis Womersley, sp. nov.

Phylum Rhodophyta – Family Delesseriaceae

Thallus (Fig. 38A, B) medium red, upper parts often bleached, 3–5 cm high, complanately and irregularly marginally branched with lower and mid thallus (3–) 5–10 mm broad, 60–120 µm thick, margin usually crenulate or with small irregular dentations, apical margin (Fig. 38C) usually entire; lower blades centrally thickened, base of blades stipe-like, 1–2 mm broad. Holdfast discoid to slightly branched, 1–3 mm across; epilithic. Structure. Growth marginal (Fig. 38D) with occasional short dentations with apical cells on young apices, segmenting with transverse walls but second-order rows apparent only for 2–4 cells below the apical cells; most marginal cells divide anticlinally, intercalary divisions frequent within the margins; surface cells irregular in shape, 20–45 µm across and L/D 1–2. Blades monostromatic and 45–60 µm thick only near the apices or margins, soon tristromatic (Fig. 38E) and 70–100 µm thick, becoming polystromatic and 80–120 µm thick, developing a central midrib region 120–400 µm and 6–16 cells thick (Fig. 38F). Cortical cells equivalent to central cells and only slightly larger. Cells probably multinucleate; rhodoplasts discoid.

Reproduction: Gametophytes probably dioecious. Procarps scattered on young blades, with a primary (supporting) cell bearing 2–3 sterile cells and a 4-celled carpogonial branch. Carposporophytes with a prominent, branched, basal fusion cell, and a much-branched gonimoblast with terminal, unbranched, chains of carposporangia (Fig. 38G), the end 3–5 cells mature, ovoid, and 35–55 µm in diameter. Cystocarps scattered, few per blade, 1.0–1.3 mm across, protruding mainly on one side of blade; pericarp ostiolate, 3–6 cells thick, slightly beaked or thickened (10–12 cells thick) around the ostiole. Spermatangial plants unknown.

Tetrasporangial sori (Fig. 38H) more or less ovate, usually submarginal, 0.5–2 mm across and 180–260 µm thick, tetrasporangia of irregular age, in 2 layers (Fig. 381), cut off from inner cortical cells and covered by outer cortical cells, subspherical, 40–75 µm in diameter.

Type from Back Beach, Little Dip Conservation Park, SE S. Aust., in shallow wave-washed pools (Womersley, 25.xi.1999); holotype (cystocarpic) in AD, A68375. Paratype (tetrasporangial) from the same locality (Womersley, 31.x.1993; AD, A63227).

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

Distribution: Known only from the above material.

Taxonomic notes: N. littledipensis is known from only 2 collections and is named from the type locality. It is characterised by form of the thallus and by the chains of ovoid carposporangia.

References: The Marine Benthic Flora of Southern Australia Part IIID

Author: H. B. S. Womersley

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. 38.

Figure 38   enlarge

Fig. 38. Nitospinosa littledipensis (A, D, E, G, AD, A68375; B, C, F, H, I, AD, A63227). A. Habit of type. B. Habit, tetrasporangial plants. C. Apex of frond. D. Frond apex with apical cells and segmentation. E. Transverse section of thallus. F. Transverse section of stipe. G. Section of Cystocarp with chains of carposporangia. H. Tetrasporangial sori near thallus margin. I. Transverse section of tetrasporangial sorus.

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