Electronic Flora of South Australia Species Fact Sheet

Caulerpa obscura Sonder.

Phylum Chlorophyta – Order Caulerpales – Family Caulerpaceae

Selected citations: Lucas 1936: 38, fig. 19. Weber van Bosse 1898: 301. Womersley 1956: 308.

Stolon robust, (1–) 2–3 (–4) mm in diameter, cartilaginous, bearing a sparse to moderate covering of simple or basally furcate, terete to tapering, spinous or rounded-tipped ramuli 1–2 (–4) mm long, and 200–300 p.m in diameter, directed forward towards the stolon apex, epilithic. Erect primary fronds (Fig. 88G) dark green, with usually simple, occasionally branched axes, usually 10–25 (–30) cm high and 2–5 (–6) cm across; axes terete, 0.7–2 mm in diameter, bearing on all sides dense second-order laterals 1–3 (–4) cm long which bear numerous ramuli irregularly arranged or sometimes tending to lie more or less in two rows; second-order laterals 350–450 µm in diameter. Ramuli (Fig. 89F1) 2–7 (–10) mm long and 250–350 µm in diameter, terete, simple or furcate just below their apices, tapering abruptly to the tip which bears 1–3 single or divided spines (Fig. 89F2).

Type from W. Aust. (Preiss); not located in MEL.

Selected specimens: Whitfords Beach, Perth, W. Aust., 6 m deep (Cook, 20.viii.1979; ADU, A50576). Ward I., S. Aust., 18–23 m deep (Shepherd, 3.iii.1980; ADU, A50889). Tiparra reef, Spencer Gulf, S. Aust., 5 m deep (Shepherd, 19.v.1971; ADU, A38574). Emu Bay, Kangaroo I., S. Aust., upper sublittoral on jetty (Womersley, 10.ii.1956; ADU, A20149). Penguin I. Beachport, S. Aust., 1–3 m deep (Lewis, 11.vi.1973; ADU, A43588). Walkerville, Vic., at low tide level on bluff (Sinkora A1515, 21.ii.1972; ADU, A42280). Guyton Point, Robbins I., Tas., upper sublittoral ( Wollaston & Mitchell, 23.ii.1964; ADU, A27598).


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

Distribution: From Yanchep Beach, W. Aust. to Walkerville, Vic. and around Tasmania. Common in pools on rock platforms and in the upper sublittoral, under rough to moderate wave action, and recorded to 35 m deep.

Taxonomic notes: C. obscura is distinguished by the second-order laterals bearing numerous ramuli, and by the spinous ramuli on the stolon. The superficially similar C. cliftonii has a naked stolon and branched ramuli borne directly on the axes, and C. flexilis has distichous second-order laterals and the stolon is covered with minute, much branched ramuli.

References:

LUCAS, A.H.S. (1936). The Seaweeds of South Australia. Pt. I. Introduction and the Green and Brown Seaweeds. (Govt Printer: Adelaide.)

WEBER van BOSSE, A. (1898). Monographie des Caulerpes. Ann. Jardin Bot. Buitenzorg 15, 243–401, Plates 20–34.

WOMERSLEY, H.B.S. (1956). A critical survey of the marine algae of southern Australia. I. Chlorophyta. Aust. J. mar. freshw. Res. 7, 343–383.

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

Author: H.B.S. Womersley

Publication: Womersley, H.B.S. (31 May, 1984)
The Marine Benthic Flora of Southern Australia
Part I
©Board of the Botanic Gardens and State Herbarium, Government of South Australia


Illustrations in Womersley Part I, 1984: FIGS 88G, 89F.

Figure 88 image

Figure 88   enlarge

Fig. 88. A. Caulerpa longifolia (ADU, A39569). B. Caulerpa longifolia f. crispata (ADU, A34035). C. Caulerpa trifaria (ADU, A33516). D. Caulerpa brownii(ADU, A26535). E. Caulerpa brownii (ADU, A46864). F. Caulerpa cliftonii(ADU, A34037). G. Caulerpa obscura (ADU, A38574). H. Caulerpa hedleyi (ADU, A38175).

Figure 89 image

Figure 89   enlarge

Fig. 89. A. Caulerpa longifolia, ramuli (ADU, A39569). B. Caulerpa longifolia f. crispata, ramuli (ADU, A34035). C. Caulerpa trifaria, ramuli (ADU, A33516). D. Caulerpa brownii, ramuli (ADU, A26535). E. Caulerpa cliftonii, branched ramulus (ADU, A34037). F. Caulerpa obscura, secondary lateral with ramuli (FI) and apex of ramulus (F2) (ADU, A38574). G. Caulerpa flexilis, ramuli (ADU, A46868). H. Caulerpa hedleyi, ramuli on axis (HI) and single ramulus (H2) (ADU, A38175).


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