- Blue markers: specimen records
- Yellow marker: type locality, if present
- Red markers: endpoints of range from literature
Gigartina Stackhouse 1809
Thalli with peglike or discoid holdfasts; fronds gregarious, relatively elongate, cylindrical or compressed to foliaceous, multiaxial, thickly or sparsely beset with papillate outgrowths, some of these clearly vegetative, others carrying reproductive structures. Medulla of delicate, cobwebby, anastomosing filaments, or with cells of various shapes and sizes. Cortex uniform, relatively thin, the cells small, oval to spherical, in 4-6(15)-celled anticlinal rows. Most species with tetrasporangial thalli similar in size and shape to gametangial thalli; in 2 species (G. agardhii and G. papillata) tetrasporangial plant crustose, not resembling erect thalli. Tetrasporangia developed from innermost cortical cells, cruciately divided, in globose to flattened sori on fertile papillae, or in chains in separate crustose stage. Spermatangia in irregularly shaped, continuous, confluent, superficial patches on papillae, sometimes spreading to flat surface of thallus; in some species entire thallus smooth, mostly without papillae, and lighter in color when spermatangial. Cystocarps making prominent bulges on papillae, in some species changing appearance of sterile thallus completely; firm, dense, internal ring of sterile tissue surrounding carposporangia.
Different species of Gigartina tend to occur in characteristic tidal zones.
Gigartina exasperata Harv. & Bail.
Harvey & Bailey 1851: 371; Scagel 1957: 185 (incl. synonymy). Gigartina californica J. Agardh 1899: 39; Setchell & Gardner 1933: 272; Smith 1944: 280.
Thalli deep brownish-red, commonly 30-50 cm tall but frequently to 1+ m, usually 2 or 3 blades 15-30 cm wide growing from single holdfast, sometimes divided from common stipe; stipes short, cylindrical, merging into flattened apophyses, these gradually flaring to 2-3 cm wide; medulla filamentous, anastomosing; base of blade broadly lanceolate with gradu ally narrowing upper portion; apex continuous or divided, blunt to pointed; northern specimens with irregular margins, some almost dentate, the C. Calif. specimens with crisp, sometimes ridged margins; papillae of most specimens short, nearly hemispherical, crisp, those in northern speci mens scattered randomly, elongate, the blades appearing thin, those in C. Calif. specimens closely placed, sometimes overlapping, the blades ap pearing thick, those in S. Calif. specimens more widely spaced; tetrasporangial papillae usually upwardly decurrent, with sharp apex, the tetrasporangial sori subterminal; spermatangial papillae with rounded apex; cystocarpic papillae broadly rounded at apex, frequently ornamented by 3 or 4 short, acuminate spines, usually only 1 cystocarp per papilla.
Common on all rocky headlands, saxicolous, subtidal (to 20 m), Vancouver I., Br. Columbia, to Pta. Maria, Baja Calif. Type locality: Strait of Juan de Fuca.
Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.
NATIVE
Type locality: USA: Washington: opposite Fort Nisqually, Puget Sound
