| Genus: |
Xiphosiphonia Savoie & G.W. Saunders |
|
Authority: |
(C. Agardh) Savoie & G.W. Saunders |
|
Description: |
Small brownish-red seaweed up to 8 cm high, with a rigid texture. Erect thalli are flattened in one plane, with several short lateral branches and occasional long branches arranged on each side of the frond giving a triangular outline. Usually 1.5-2 mm wide and it is up to 6 mm wide when main axes are branched. It has regular alternate lateral branching on every second axial segment. Brownish-red colour;Rigid texture;Up to 8 cm height;Regular alternate branching on every second axial segment. |
| Name History |
Adjective (Latin), pinnate (Stearn 1973). |
| Biogeography |
Widely distributed in Atlantic and PacificOceans. In southern Australia |
| Life Cycle |
Gametophytes dioecious; one case of mixed phases (male on tetrasporophyte) known. Procarps probably borne on short trichoblasts, segments soon polysiphonous. Carposporophyte with a small basal fusion cell, short gonimoblast filaments and clavate terminal carposporangia 30–45 µm in diameter. Cystocarps ovoid, short-stalked, 300–800 µm in diameter; pericarp ostiolate, ecorticate, 2 cells thick, outer cells isodiametric. Spermatangial organs near apex of axes, elongate-ovoid to clavate and often curved, 45–120 µm in diameter and 130–350 µm long, with 1–2 sterile basal and apical cells.Tetrasporangia indeterminate laterals in straight rows in 6–10 successive segments, subspherical to slightly ovoid, 35–60 µm in diameter, with 2 elongate cover cells. |
| References |
Díaz Tapia, P. & Bárbara, I. (2004). Pterosiphonia pennata versus P. pinnulata (Ceramiales, Rhodophyta) en el noroeste de la Península Ibérica. Anales de Bíologia 26: 47-59. Lauret, M. (1967). Présence de trichoblastes végétatifs chez Pterosiphonia pennata (Roth) Falkenberg. Note. C.R. Acad. Sc. Paris, Série D 265: 1901-1904. Masuda, M. (1973). The life history of Pterosiphonia pennata (Roth) Falkenberg (Rhodophyceae, Ceramiales) in culture. Japanese Journal of Botany 48: 122-127. Rojas-Gonzalez, B. & Afonso-Carrillo, J. (2001). Morphology and distribution of Pterosiphonia pennata in the Canary Islands (Rhodophyta, Rhodomelaceae). Vieraea 29: 71-78. |
| Habitat: |
Forms mats or turfs close to low tide level under moderate wave action, rarely in deep water (Womersley 2003: 340). Pterosiphonia pennata prefers moderately exposed to extremely wave-sheltered sites. |
| Type information: |
Type species
The type species (holotype) of the genus Xiphosiphonia is Xiphosiphonia ardreana (Maggs & Hommersand) Savoie & G.W. Saunders
Status of nameBasionym
Hutchinsia pennata C. Agardh
Type information
Syntype localities: "In mari Mediterraneo. — In mari Atlantica ad Gades." [Mediterranean, Atlantic at Cadíz] (Agardh 1824: 124). Lectotype: LD Herb. Alg. Agardh 39271 (Womersley 2003: 340). Notes: Lectotype selected from Mediterranean |
