Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Ceramiales

Family Wrangeliaceae

Griffithsia subbiconica Stegenga 1986: 114, 116, pl. 41

Plants with a creeping proximal part and erect terminal parts up to ca. 2 cm high. Thallus branched dichotomously, as a rule every segment. Plants attached by rhizoids from the acropetal end of the older cells. Cells up to 1500 µm long and 500 µm broad, but up to 1000 µm broad when bearing reproductive structures, the cells somewhat obovate.

Tetrasporangia in several clusters in concentric rings on a subapical cell, the apical cell of the axis similarly inflated. The outer ring of tetrasporangial clusters bearing one or two involucral cells as well on the tetrasporiferous cell. Up to 20 involucral cells may be found in a circle. Tetrasporangia at maturity ca. 75 x 70 µm. Spermatangial clusters profusely branched, ca. 15 clusters on a subapical cell, the apical cell swollen likewise. No involucral cells present in the male structure. Female reproductive structure developing on a subapical cell, the apical cell markedly asymmetric and bending over the developing carposporophyte, the enveloping structure completed by ca. six relatively small two-celled involucral filaments developed from the basal cell of the female fertile filament. Carposporophyte with many relatively small gonimoblasts, the ripe carpospores measuring ca. 35 µm in largest diameter.

Collections, ecology and regional distribution

Not uncommon between Swartklip and East London (18-43), although not as common as G. confervoides. A turf-forming species in shaded localities and in the lower intertidal, also in tidal pools (Stegenga et al. 1997).

World distribution: Type locality: Koppie Alleen, Cape Province, South Africa (Stegenga 1986).

Note: This species is sometimes regarded as synonymous with G. schousboei Montagne (Norris & Molloy, 1988). It has however not been found east of Bat’s Cave (East London), while G. schousboei is supposed to be a tropical and subtropical species.

 

Griffithsia subbiconica. 1 Habit (female). 2 Tetrasporangial stand. 3 Detail of terasporangial stand. Reproduced from Stegenga et al. (1997).

Griffithsia subbiconica. Tetrasporangial stands, stained slide, Goukamma.

Griffithsia subbiconica. Detail of tetrasporangial stand, stained slide, Goukamma.

Griffithsia subbiconica. Carposporophytes, stained slide, Goukamma.

Griffithsia subbiconica. Detail of carposporophytes, stained slide, Goukamma.

 

References Griffithsia subbiconica

Norris, R.E. and F. Molloy. 1988. Griffithsia schousboei (Ceramiaceae, Rhodophyceae), a species new to South Africa. South African Journal of Botany 54(5): 477-480.

Stegenga, H. 1986. The Ceramiaceae (excl. Ceramium) (Rhodophyta) of the South West Cape Province, South Africa. Bibliotheca Phycologica 74: 1-149, 1 table, 51 plates.

Stegenga, H., Bolton, J.J. & R. J. Anderson. 1997. Seaweeds of the South African west coast. Contributions from the Bolus Herbarium 18: 655 pp.

 

Cite this record as:

Anderson RJ, Stegenga H, Bolton JJ. 2016. Seaweeds of the South African South Coast.
World Wide Web electronic publication, University of Cape Town, http://southafrseaweeds.uct.ac.za; Accessed on 20 April 2024.