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Order Rhodymeniales

Family Hymenocladiaceae

Hymenocladia kallymenioides (Holmes) F. Schmitz 1896: 8-13

Plants dark- to brownish-red, comprising broad, flat, often incised blade to 30 cm long, with short stipe (0.5-1.0 cm) and discoid holdfast. Blade flat, simple, becoming irregularly palmately incised and sometimes perforated, midrib and veins absent, margins entire or toothed; blades usually with scattered dark patches and striae, and often with light patches. Stucture of large clear medullary cells and very small outer cortical cells; clear gland cells visible in inner cortex. Medulla of 1-3 layers of large (to 150 µm diameter) cells, interspersed with smaller secondary cells in older thallus parts; cortex of several layers (2-3 or more in older parts) of smaller pigmented cells becoming very small (abut 5-8 µm long) towards surface. Tetrasporangia about 60 µm long (visible with naked eye), submerged in cortex and extending into medulla, tetrahedrally divided. Cystocarps visible to naked eye as pustule-like swellings (up to1 mm diameter), scattered on one surface of blade; developing between medulla and cortex, with carpostome; carpospores about 25 µm in diameter. Male structures not seen.

Collections, ecology and regional distribution

Found from Addo to Mkambati (38-47) in the sublittoral fringe and below.

World distribution: Also recorded from Madagascar (Silva et al. 1996).

Type locality: Mouth of Kowie River, Port Alfred (Silva et al. 1996).

Note: Details of the structure and reproduction in this species are provided by Sparling (1957). She notes that the dark patches in the thalli are caused by pigmentation in some of the cortical cells, rather than by separate (e.g. reproductive) structures.


Hymenocladia kallymenioides, Kowie (BOL).

Hymenocladia kallymenioides, Kowie (BOL). Detail of blade showing dark spots and striae.

Hymenocladia kallymenioides, XS of young part of blade (re-drawn from Sparling (1957; Fig. 15 e).

Hymenocladia kallymenioides, section of blade with tetrasporangia (re-drawn from Sparling (1957: Fig 15 a).

Hymenocladia kallymenioides, fresh, smallish specimens.


References Hymenocladia kallymenioides

Schmitz, F. 1896. Kleinere Beiträge zur Kenntniss der Florideen. VI. Nuova Notarisia 7: 1-22.

Silva, P.C., Basson, P.W. & Moe, R.L. 1996. Catalogue of the benthic marine algae of the Indian Ocean. University of California Publications in Botany 79: 1-1259.

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,; Accessed on 02 March 2024.