Electronic Flora of South Australia Genus Fact Sheet

Genus POLYCEREA J. Agardh 1882: 46

Phylum Phaeophyta – Order Chordariales – Family Chordariaceae

Thallus usually with abundant, long branches, cylindrical, mucoid, 5–20 cm long and 1–3 mm in diameter. Medulla multiaxial, of parallel longitudinal filaments (with slight production of hyphae), becoming hollow. Subcortex absent to slight and rarely more than a single cell. Cortex of simple, straight, determinate, assimilatory filaments arising singly from outer medullary cells or in small groups from the single subcortical cells, usually 8–15 cells long with the terminal cells enlarged. Phaeophycean hairs present, arising from outer medullary or subcortical cells.

Reproduction: Reproduction by plurilocular sporangia borne terminally on filaments within the cortex, usually with a 1–6 celled pedicel, simple or branched, lanceolate, multiseriate, and by unilocular sporangia borne on lower cortical cells.

Life history unknown.

Type species: P. ramulosa J. Agardh [=P. nigrescens (Harvey ex Kützing) Kylin].

Taxonomic notes: Polycerea is distinguished by the form of the plurilocular sporangia and their position within the cortex, the relatively short, straight or slightly curved cortical filaments with an enlarged, subspherical terminal cell, and the virtual absence of a subcortex.

Apart from the type species, the genus contains only P. zostericola (Harvey ex Kützing) Kylin.

References:

AGARDH, J.G. (1882). Till algernes systematik. Acta Univ. lund. 17, 1–136, Plates 1–3.

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

Author: H.B.S. Womersley & A. Bailey

Publication: Womersley, H.B.S. (14 December, 1987)
The Marine Benthic Flora of Southern Australia
Part II
©Board of the Botanic Gardens and State Herbarium, Government of South Australia

KEY TO SPECIES OF POLYCEREA

1. Cortical filaments 6–9 (–10) cells long, with the mature terminal cell 30–60 µm in diameter and (2–) 2.5–5 times the diameter of the subterminal cell; hairs usually 16–25 (–30) µm in diameter

P. nigrescens

1. Cortical filaments 8–13 cells long, with the mature terminal cell 22–32 µm in diameter and 1.5–2 times the diameter of the subterminal cell; hairs 8–16 (–18) µm in diameter

P. zostericola


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