Ganonema farinosum (J.V. Lamour.) K.C. Fan & Yung C. Wang

Ganonema farinosum (J.V. Lamour.) K.C. Fan & Yung C. Wang

Family

Liagoraceae

Synonyms

Liagora farinosa J.V. Lamour., Liagora cheyneana Harv.

Vernacular Names

Philippines Baris-baris (Ilokano).

Geographical Distributions

Ganonema farinosum is widely distributed in the tropical waters of the Atlantic, Pacific and Indian Oceans. In Southeast Asia, it has been recorded from Thailand, Vietnam, Malaysia, Indonesia (Irian Jaya) and the Philippines.

Description

This alga is soft, smooth and about 13 cm tall. It is pinkish, lightly calcified, farinose and attached by small discoid holdfasts. The branching pattern is basically dichotomous, with interdichotomal lengths decreasing towards terminal portions of the thallus. The branches are numerous, cylindrical, measuring about 1.5 mm in diametre, with forking apices into very short, acute and terminal branchlets. The assimilatory filaments are about 445 µm long and 30 µm broad. The cells are nearly necklace-shaped throughout. The cells of mature medullary filaments are broad (more than 40 µm in diametre).

Life cycle is triphasic, diplohaplontic and heteromorphic while the gametophytes are dioecious. The antheridia are borne in head-shaped clusters at tips of assimilatory filaments. The carpogonial branches are straight to slightly curved and frequently compound. The carposporophyte is compact, with terminal carposporangia and with little or no post-fertilisation fusion of carpogonial branch cells. The tetrasporophytes are only seen in laboratory culture, forming semicircular cushions (about 5 mm in diametre), Acrochaetium-like, filamentous, heterotrichous, with markedly ramifying creeping systems and sparsely erect branched monosiphonous parts, measuring 14-18 µm wide and carrying scattered wide hairs on the apical cells. Each cell is with star-shaped chloroplast and large pyrenoid. The tetrasporangia and monosporangia are in small clusters at the terminal of erect filaments. The tetraspores measure 14-16 µm in diametre while monospores are 20-22 µm in diametre.

Ecology / Cultivation

Ganonema farinosum is found attached to rocky substrate among other algae in the subtidal and intertidal areas exposed to air during low tides.

Line Drawing / Photograph

Ganonema_farinosum

References

  1. Plant Resources of South-East Asia No.15(1): Cryptogams: Algae.