- 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 harveyana (Kütz.) S. & G.
Mastocarpus harveyanus Kützing 1849: 734. Gigartina harveyana (Kütz.) Setchell & Gardner 1933: 276; Smith 1944: 282 (incl. synonymy); Dawson 1961a: 268. G. boryi S. & G. 1933: 269.
Thalli rusty red, 25-30(90) cm tall, in clumps, lax, with or without linear to lanceolate proliferations crowded in upper portions of blades; proliferations 2-8 cm long, 1-3 cm wide, with attenuated apices; blades linearlanceolate to lanceolate, with attenuated apices, occasionally simple, or divided several times at base; short stipe sometimes present, usually dissected; medulla filamentous, with irregular cells; papillae numerous, narrow, soft, frequently wide and flattened, on blade surfaces and margins; tetrasporangial papillae elongate, 3-9 mm long, the sori crowded, producing rugose surfaces; spermatangial thalli mostly smooth, with rudimentary papillae on blade surfaces; cystocarpic papillae usually marginal on proliferations and edges of blades, the papilla round and swollen at apex by single cystocarp.
Locally abundant in areas of fine sand covering low rocks, low intertidal (but higher than G. corymbifera), occasionally subtidal (to 5 m), Wash. to Pta. Maria, Baja Calif. Type locality: Monterey, Calif.
At one time, it seemed practical to recognize both G. harveyana and G. boryi; but in extensive collections the characters that had been used to separate them are found on the same plants as well as in different populations.
Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.
