Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Rhodymeniales

Family Rhodymeniaceae

Erythrymenia obovata Schmitz ex Mazza 1921: 107-111

Plants erect, stiff, orange-red with striking blue-green or golden iridescence when fresh, comprising one to several thick, obovate blades tapering basally to a stipe and crustose holdfast; blades up to 10 cm (rarely to 20 cm) long, 1.5 to 5 cm (rarely to 7 cm) wide and from about 400 µm thick near the apex to about 700 µm thick near the base; margins spinose except when worn smooth, blade surfaces smooth in young plants, with stout spinose protrusions in older plants. Structure of a compact medulla initially of only large hyaline cells (80-125 µm in diameter) that subsequently become interspersed with smaller secondary cells; cortex of 3-5 layers of pigmented cells that become smaller towards the surface, to outer cells 2.5-5 µm in diameter. Plants dioecious; cystocarps immersed in both sides of blades; spermatangia in sori covering most of thalli; tetrasporangia about 60 µm long, cruciately to irregularly divided, arranged in nemathecia.

Collections, ecology and regional distribution

Recorded from Port Alfred to Shelly Beach in southern Kwazulu-Natal (39-49). Found in the sublittoral fringe on wave-exposed shores.

World distribution: South African endemic.

Type locality: Port Alfred (Sparling 1957).

Note: E. obovata is described in detail by Sparling (1957).

 

Erythrymenia obovata, Kenton-on-Sea.

Erythrymenia obovata, Kenton-on-Sea, spiny protrusions and golden iridescence on blade surface.

 

References Erythrymenia obovata

Mazza, A. 1921. Aggiunte al saggio di algologia oceanica (Florideae). Nuova Notarisia 32: 1-48, 73-132.

Sparling, S. R. 1957. The structure and reproduction of some members of the Rhodymeniaceae. University of California Publications in Botany 29: 319-396.

 

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 26 April 2024.