Padina (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Padina australis - 1, habit. P. antillarum - 2, detail of lower surface of a blade with double lines of tetrasporangia aside hair lines; 3, detail of section of double indusiate sori with oogonia; 4, detail of section of double non-indusiate sori with tetrasporangia. P. sanctae-crucis - 5, habit; 6, detail of section of circinnately inrolled margin of blade; 7, detail of section of non-indusiate antheridial sorus.

Padina Adans.

Protologue: Fam. Pl., part. 2: 13, 586 (1763).

Family: Dictyotaceae

Chromosome number: x= unknown

Major species and synonyms

• Padina antillarum (Kütz.) Picc., Alg. viagg. Vettor Pisani: 36 (1886), synonym: P. tetrastromatica Hauck (1887) [1886-1889].

• Padina australis Hauck, Hedwigia 25: 44 (1887) [1886-1889], synonym: often recorded as P. gymnospora (Kütz.) Sond., which is, however, probably a Caribbean species.

• Padina boryana Thivy, in W.R. Taylor, Pacific Sc. 20: 355-356, fig. 2 (1966), synonyms (misapplied names): P. commersonii Bory (1828) [1826-1829], nom. illegit.; P. tenuis (C. Agardh) Bory (1827); it is suggested the name P. tenuis Bory (1827) be considered as a newly described species, and then that name will have priority over P. boryana Thivy.

• Padina minor Yamada, Bot. Mag. (Tokyo) 39: 251-252, fig. 5 (1925).

• Padina sanctae-crucis Børgesen, Mar. agl. Danish W. Ind., Chloroph.: 45 (1914), synonym: P. japonica Yamada (1931).

Vernacular names

• Abanico (Sp).

Origin and geographic distribution

Padina occurs along all tropical and warm temperate sea coasts. In South-East Asia most Padina can be found on almost all coasts, although P. antillarum and P. boryana are less frequent.

Uses

All Padina can be used as fertilizer or as a source of the phycocolloid alginate. P. antillarum and P. australis are occasionally used as human food.

Production and international trade

No production data are available for Padina. Biomass is obtained from natural stocks.

Description

• Thalli flabellate, brown or whitish by a thin deposit of lime, often conspicuously zonate, attached by compacted rhizoidal holdfast; stipe often invested by rhizoids.
• Blades 2 to several cells thick, zonate, with zones marked by concentric rows of hairs, sometimes divided into narrow spatulate segments.
• Side to which blades are inrolled is called the upper surface of the blades.
• Life cycle diplo-haplontic and isomorphic.
• Gametophytes dioecious or monoecious.
• Reproductive cells (sporangia, gametangia) on blades scattered or in sori between hair bands.

P. antillarum.

• Blades green-brown or yellow-brown, 5-10 cm tall, divided into few flabellate, lateral lobes, characteristically 4-6 cells thick, except at margins (2 cells thick); base rough, thicker.
• Calcification of blades usually conspicuous.
• Concentric hair lines well developed on lower surface of blade, at equal distance; faint lines in between hair lines present, especially at middle to lower portions of thallus.
• No "Vaughaniella" growth stages observed.
• Gametophytes dioecious, male plant generally smaller, paler and less lobed than female plant.
• Sporophytes generally larger, thicker, dark brown.
• Reproductive sori forming concentric lines on both sides of hair zones on lower blade surface.
• In male thallus, sori scattered in patches.
• Sporangia globular, 55-59 μm in diameter; mature sporangia without indusia, but indusium present in young stages.
• Oogonia globular, 30-35 μm in diameter, arranged in closed bands, with indusia; antheridia rectangular, about 30 μm × 30 μm, without indusia.

P. australis.

• Thalli large, frondose, to about 15 cm tall, light brown, whitish in some portion due to slight calcification.
• Blades divided into several fan-shaped lobes, 2-8 cm broad, 2 cells thick throughout; blade surface divided into wide and narrow, glabrous zones by distinct concentric hair lines or filiferous zones, those on lower surface alternating with those on upper surface; narrow glabrous zones 1-2 mm wide; sterile, glabrous zones 2.5-3.0 mm wide, broader near margin.
• Rarely with "Vaughaniella" stages.
• Reproductive sori located at middle of narrow glabrous zone, usually on lower blade surface. Sporangia globose, without indusia, 59-85 μm in diameter.
• Gametophytes monoecious.
• Oogonia globose, 20-30 μm in diameter, rather irregularly arranged, with indusium; antheridia rectangular, 15-25 μm × 16-28 μm, without indusium.

P. boryana.

• Blades yellow-brown, 8-10 cm tall, flabelliform, usually split into several segments, slightly encrusted with chalk on upper surface, composed of 2 layers of rectangular, thin-walled cells about 60-70 μm thick, those near base 85-90 μm thick; holdfast stupose, covered with brown hairs. "Vaughaniella" stages common.
• Concentric hair lines on blades conspicuous.
• Tetrasporangia forming sori, without indusium, in every glabrous zone, regularly arranged just above every hair line on lower blade surface.

P. minor.

• Blades flabellate, yellow-brown or green-brown, light brown or whitish, 3-12 cm tall, divided into several flabellate lobes, 1-3 cm wide and 2 cells thick throughout, usually conspicuously calcified.
• Lower blade surface divided into concentric zones by equidistant hair lines; upper surface without hairs. "Vaughaniella" stages common.
• Reproductive sori forming concentric lines directly above each hair line.
• Sporangia globose, without indusia, 59-85 μm in diameter.
• Gametophytes dioecious.
• Oogonia globose, 19-31 μm in diameter, irregularly arranged, with indusium; antheridia rectangular, 13-23 μm × 17-27 μm, without indusium.

P. sanctae-crucis.

• Blades brown to yellow-brown, 1-2 cm tall, flabelliform, often split into several segments, moderately calcified on upper surface, shortly stipitate, hairy near base, composed of two layers of rectangular, thin-walled cells, about 90-100 μm thick.
• "Vaughaniella" stages common.
• Hair lines conspicuous, mostly on lower surface; spaces between hair lines rather narrow, on upper surface faint hair lines discernable.
• Reproductive sori just above every other hair line at lower blade surface; occasionally becoming incomplete double line with additional, discontinuous sori present along lower side of hair lines.
• Sporangia globose, 25-35 μm in diameter, all markedly indusiate.
• Gametophytes dioecious.
• Oogonia globose, 30-40 μm in diameter, in closely packed line-forming sori, indusiate; antheridia rectangular, about 30 μm in diameter, closely packed in line-forming sori, indusiate.

Growth and development

The blades of Padina grow by the many apical cells at the distal, curved, involute margin. In many cases an extensive, prostrate, pinnate branch system ("Vaughaniella"-stage) is developed from which the blades arise, attached by basal rhizoids. Flabellate branches may be produced from these branches.

Other botanical information

Some authors consider P. boryana (often cited as "P. tenuis") and P. minor as synonyms, but others have continued to recognize them as two separate species.

Ecology

Padina is ubiquitous. Its different species can be found in a very wide range of habitats extending from intertidal to subtidal zones to a depth of 15-20 m in areas characterized by clear water. They can grow attached to different types of solid substrates as well as epiphytically on large seaweeds such as Sargassum spp. They are very abundant during the sunny months of the year.

Propagation and planting

Padina is not known in phycoculture.

Handling after harvest

Padina is used fresh or sun-dried.

Prospects

No development prospects are expected for Padina in the near future.

Literature

• Gaillard, J., 1967. Etude monographique de Padina tetrastromatica (Hauck) [Monographic study of Padina tetrastromatica (Hauck)]. Bulletin de l'Institut Fondamental d'Afrique Noire 29, série A: 447-463.
• Gaillard, J., 1975. Padina sanctae-crucis Boergesen, Padina japonica Yamada, Padina haitensis Thivy et leurs affinités [Padina sanctae-crucis Boergesen, Padina japonica Yamada, Padina haitensis Thivy and their affinity]. Le Botaniste 57: 85-103.
• Lewmanomont, K., 1980. Taxonomic study of the genus Padina of Thailand. In: Desikachary, T.V. & Rao, V.N.R. (Editors): Taxonomy of algae. Papers presented at the international symposium on taxonomy of algae, held at the Centre of Advanced Study in Botany, University of Madras, December 9-16, 1974. Madras, India. pp. 755-763, plates I & II.
• Wynne, M.J., 1998. A study of Padina antillarum (Kützing) Piccone and a comparison with P. tetrastromatica Hauck (Dictyotales, Phaeophyta). Cryptogamie, Algologie 19: 271-289.

Sources of illustration

Gaillard, J., 1967. Etude monographique de Padina tetrastromatica (Hauck) [Morphologic study of Padina tetrastromatica (Hauck)]. Bulletin de l'Institut Fondamental d'Afrique Noire 29, sér. A, (2): fig. 2, p. 450 (detail of lower surface of blade of P. tetrastromatica [= P. antillarum]), fig. 5, p. 457 (details of double sori); Gaillard, J., 1975. Padina sanctae-crucis Børgesen, Padina japonica Yamada, Padina haitensis Thivy et leurs affinités [Padina sanctae-crucis Børgesen, Padina japonica Yamada, Padina haitensis Thivy and their affinities]. Le Botaniste 57: fig. 4, p. 99 (section of margin and antheridial sorus), fig. 5, p. 100 (habit of P. sanctae-crucis [as P. japonica]); Trono, G.C. & Ganzon-Fortes, E.T., 1988. Philippine seaweeds. National Bookstore, Manila, The Philippines. Fig. 63A, p. 91 (habit P. australis). Redrawn and adapted by P. Verheij-Hayes.

Authors

• G.C. Trono Jr