Smithora naiadum
Seagrass Laver
Alaska to Mexico
Family Erythrotrichiaceae

Smithora naiadum (the genus is named after Gilbert M. Smith who authored “Marine Algae of the Monterey Peninsula”; the species name is derived from Latin for “water nymph”) is a delicate red-algal epiphyte on the seagrasses Zostera and Phyllospadix. It is pictured here on Zostera. The wine-red blade is monostromatic (it is one-cell thick) and wedge-shaped, broader at the tip and narrowing toward the holdfast. Porphyra, another thin-bladed alga, may also grow on seagrasses, but Smithsora can be identified by its discoid attachment to the seagrass instead of by the rhizoidal cells that secure Porphyra.  You can find Smithora on Zostera in Netarts Bay and on Phyllospadix on wave-swept rocks during summer months.

Porphyra sp.
Laver, Nori
Alaska to Mexico
Family Bangiaceae

There are many species of Porphyra. The species pictured here is lives in the middle and upper tidal zones, is greenish-brown, monostromatic – the thallus is only one cell thick – and, each cell has a single plastid. It may be P. lanceolata, which has these characters, but so do other species. It likes sunlight and grows on the tops and upper sides of rocks, and blades may reach over a foot long. It can withstand almost total dehydration. The rock in the picture looks like it is having a bad hair day.

Known as Nori in Japan, Porphyra is edible and nutritious, and some species are tasty, giving rise to a huge aquaculture industry in the Far East. Japanese use dried Nori as a wrap for their cookies, crackers, and sushi. Our Porphyra here, while edible, is a bit on the rubbery side with a slight salty taste.
 

Bossiella californica (?)
California Winged Coral Seaweed
British Columbia to southern California
Family Corallinaceae

This erect, jointed coralline algae resides in wave swept, rocky, lower intertidal and subtidal zones. It has an irregular dichotomous branching pattern, which means its branches are sort of dichotomously arranged. The thallus is composed of pink to purple, calcified segments (called intergenicula in seaweed keys) shaped like flattened wing nuts and lined up end to end. Segments of B. californica are generally two or more millimeters in length. When reproductively active, each will have two to four conceptacles, the bumps you see on the surface of the wings. This arrangement of conceptacles distinguishes Bosiella from Calliarthron which has conceptacles along the margins of its segments.  There were a couple of subspecies described in Abbott and Hollenberg (1976) that have been elevated to the species level (see: http://bio.classes.ucsc.edu/bio170/2007_mac_names.doc.).
 

Bossiella orbigniana (?)
Winged Coral Seaweed
British Columbia to Mexico
Family Corallinaceae

This Bossiella can be abundant in the mid intertidal zone, growing on the upper sides of large rocks.  It also has irregular dichotomous branching.  Its segments are smaller than B. californiana, a millimeter or less in length, and there usually two (sometimes three or four) conceptacles on each when the alga is reproductive.  I have placed question marks next to the names because this can be a difficult species, and these identifications need to be verified.  This specimen was collected from Tunnel Beach during late October. As with B. californiana, there were a couple of subspecies described in Abbott and Hollenberg (1976) that have been elevated to the species level.
 

Corallina vancouveriensis
Graceful Coral Seaweed
Aleutian Islands, Alaska to Mexico
Family Corallinaceae

This delicate coralline is found in the same local as Bossiella, where they often grow next to each other. It is pinnately branched. Its segments are fairly cylindrical, a millimeter or less long, without wings, and few if any conceptacles.  Each segment of the main axis has two branches, one on each side. These segmental characters distinguish C. vancouveriensis from other species of Corallina. 

 

Melobesia mediocris
Seagrass Crust
British Columbia to Baja Califonia
Family Corallinaceae

This crustose coraline alga is easy to identify because it only occurs as an epiphyte on the seagrasses Zostera and Phyllospadix. It is pictured here on Phyllospadix. It grows as small round patches that enlarge and push against each other until they finally coalesce into a dense coating. The small holes in the surface lead to male and female conceptacles. 
 

Crustose coralline algae
Family Corallinaceae

Coraline algae come in two different characteristic modes of growth – erect or encrusting. The coralines describe above are the erect kind. The encrusting ones, or crustose algae as they are called, can be seen at almost any low tide covering rocks, shells, and other hard substrates, looking like patches of crusty pink paint. They include genera such as Mesophyllum, Lithophyllum, Melobesia, Pseudolithophyllum, Lithothamnion, and Phymatolithon, all difficult to identify without a microscope. Coraline algae contain deposits of calcium carbonate in their cell walls. In spite of their appearance and calcium carbonate, they like other coralines, are photosynthetic and contain chlorophyll. Their knobby surfaces conceal reproductive conceptacles. These kinds of algae are cosmopolitan, occurring in all seas.
 

Halosaccion glandiforme
Sea Sacs
Aleutian Islands, Alaska to Point Conception, California
Family Palmariaceae

These hollow, yellowish-brown to red thalli look like slightly inflated fingers of a latex surgeon’s glove. They are yellowish when growing in sunlight, redder when in the shade. The sacs are filled with seawater, admitted through pores in the sac wall, except for a bubble of oxygen in the tip, produced by photosynthesis. Halosaccion inhabits rough, wave-swept rocks in the mid intertidal zone. The water in the sacs keep the alga cool when exposed to sunlight at low tide. A thin stipe attaches each sac to a small discoid holdfast. The aerodynamic shape of the thallus allows Halosaccion to resist being detached from rocks in heavy surf. I have yet to find Halosaccion growing between the Capes, but it is commonly washed ashore and can be found while walking the beaches.

Neoptilota hypnoides
Sea Fern
Alaska to central California
Family Ceraminaceae

The Sea Fern is an uncommon red alga from the mid to low intertidal zones that grows on rocks or is epiphytic on coralline algae. The one pictured here was found on wave-swept rocks off Tunnel Beach. It has a flat, bipinnate thallus with alternately arranged branches, the primary branches stemming from a central midrib. The ultimate branchlets are small and blade-like with smooth edges, which distinguish this Neoptilota from other species whose ultimate branchlets are serrated. In the lower photograph, you can see short fertile branchlets alternating with sterile branchlets.
 

Cryptopleura ruprechtiana
Hidden Rib
Alaska to Baja California
Family Delesseriaceae

The genus Cryptopleura is Greek for “hidden rib”. A distinct midrib at the base of this rose-red alga fades into a network of faint to microscopic veins toward the upper parts of the thallus. The blades, thin and deeply divided, are fringed with outgrowths or ruffles at the middle and bases of the lobes. Reproductive structures may reside in the fringes. It can be fairly abundant on the outer rocks along Tunnel Beach, growing where surf can be heavy. In the past, this alga was placed in the genus Botryoglossum; some phycologists think it should remain there.
 

Hymenena flabelligera
Black-lined Red Seaweed
Alaska to central California
Family Delesseriaceae

As Louis Druehl points out in his guide “Pacific Seaweeds”, the genus Hymenena can be confused by beginners with the genera Cryptopleura and Botryoglossum. There are distinct similarities. They are all in the family Delesseriaceae, and if you look at the illustrations in “Marine Algae of California” by Abbott and Hollenberg, you will see their physical resemblance to each other. The blades are flat, thin, similarly branched. You will also see differences in the reproductive structures, but they occur only in the sporophyte (technically, the tetrasporophyte) where the sori are in different locations. Hymenena flabelligera has longitudinal lines of sori running from the base of the thallus almost to the ends of the divided tips. Its thallus is usually longer than 6 inches. It grows on rocks in low intertidal to subtidal zones. The specimens pictured here were found on the cobbled bottom of Netarts Bay near Happy Camp.

Neorhodomela larix
Black Pine
Alaska to Baja Califonia
Family Rhodomelaceae

Neorhodmela larix, a course red alga, blackish brown in color, has short side branchlets in clusters like needles on a larch tree (hence the species name larix) growing spirally on a central stem.  It is common on rocks in the higher intertidal zone, often where waves beat the shoreline. It is a perennial that dies back during winter, but grows rapidly in spring and summer. It is another alga that periodically gets covered by sand but still survives and resumes growth after it emerges from burial. There is speculation that periodic covering may discourage herbivores, such as the black chiton Katharina tunicata, that do not tolerate sand. This species can survive a wide range of temperatures.
 

Odonthalia flocosa
Sea Brush
Aleutian Islands, Alaska to central California
Family Rhaodomelaceae

Odonthalia flocosa (the genus, from Greek, means “toothed twig”; the species, from Latin, means “flock of wool” ) is a member of the phylum Rhodophyta, the red algae, even though it appears more brownish than red. Sea Brush typically occurs on rocks where there is moderate wave action or, sometimes, in more protected waters.  I have found it lining tide pool edges fairly high in the intertidal zone. One such pool is in the basalt rocks near the man-made arch between Tunnel Beach and Lost Boy Beach.  Another is a large pool on the rocks at the north end of Short Beach.  O. flocosa is a profusly branched alga. Secondary branches alternate off the main stem, which is little more than a millimeter in diameter. Tertiary branchlets are pretty much equal in length. The tips of female gametophyte individuals may have a cluster of tertiary branchlets, called calcars, which surround a cystocarp, the structure that contains female reproductive cells, the carpogonia. The entire thallus may grow to more than a foot in height before being knocked back in winter. One way of telling O. flacosa from other species of Odonthalia is that the branches are not flattened. They are almost round in cross section. 
 

Polysiphonia sp.
Poly
Alaska to Baja California
Family Rhodomelaceae

There are numerous species and subspecies of Polysiphonia along the Pacific Coast. You can find this filamentous red alga in tufts attached to rocks in the mid to low intertidal zone. The name is derived from Latin means “many tubes”, and as you can see from the micrograph, the thallus consists of stacks of narrow, cylindrical cells.  Each “segment” contains a central axial cell surrounded by equal length pericentral cells.  There may be as few as four pericentral cells in some species, to numerous pericentral cells in others.  The branches are narrow, less than a millimeter or two in diameter, so microscopic examination is required to properly identify a species.  The one pictured here is probably P. hendryi, of which there are four subspecies (see below).

 

Constantinea simplex
Cup and Saucer Seaweed
Alaska to Point Conception, California
Family Dumontiaceae

This unusual looking and easily recognized red alga with its cup-shaped blade grows on lower intertidal and subtidal rocks. This one was found during a very low summer tide on some low lying, wave-exposed, outer rocks just northwest to Maxwell Point. It is a perennial with a single stipe that produces a new blade yearly. A small nubbin in the center of the blade develops into a new stipe above the existing one during the summer. In the fall a new blade is formed on the new (or extended) stipe, and the older blade erodes away during the winter. The age of the alga can be determined by counting the number of blade scars on the stipe.

Extracts from C. simplex have been investigated for drug use, including antiviral properties. An isolated structural polysaccharide may provide relief from herpes and other viral infections. 

 

Cryptosiphonia woodii
Bleached Brunette (An Alaskan name)
Alaska to central California
Family Dumontiaceae

The common name refers to this red alga turning a dirty blond late in the summer. We can find it growing in tufts on rocks in the mid tide zone, where it can be abundant during late spring and summer. The sporophyte and gametophyte generations are isomorphic, and gametophytes have separate sexes. The thallus, stemming from a discoid holdfast, is highly branched. Branches are tapered at their tips and bases.

Like Contantinea, and Farlowia, aqueous extracts of Cryptosiphonia have promise as a treatment for herpes. The active ingredient is believed to be a polysaccharide.

 

Farlowia mollis
Farlow’s Seaweed
Alaska to Baja California
Family Dumontiaceae

Farlow’s seaweed is a dark red alga with flattened, ribbon-like branches that can be found along the edges of some of the tide pools at Tunnel Beach.  Branching is mainly distichous, that is it has branches on two sides of a main axis, but the branching is fairly irregular, making the alga look weathered.  The terminal branches may become more cylindrical.  It grows on rocks (“saxicolous” is the technical term for “growing on rocks”), and it is another alga that can withstand being buried in sand.  The genus is named after William Gilson Farlow, a professor of cryptogamic botany at Havard University, who published on fungi, algae, and plant diseases.  Farlowia mollis has recently been examined as a source of various pharmaceuticals and unusual biochemicals produced by this alga, including those that have antiviral properties.
 

Endocladia muricata
Sea Moss, Nail Brush Seaweed
Aleutian Islands, Alaska to Baja California
Family Endocladiaceae

This seaweed, a frequent food for the limpets that cling to rocks high out of the water, lives in the upper intertidal region, mostly in the splash zone.  It attaches to rocks, California mussels, barnacles, and almost any hard surface by a small, discoid holdfast.  It grows as profusely branched tufts and, where dense enough, will form wiry mats.  Its branches are cylindrical and covered with short, soft spines.  When wet, it a yellow to reddish brown.  When dry - and this seaweed can desiccate until it is almost crisp - it is a brownish black.  It likes sunlight, can withstand high variations in temperature, and it is usually exposed to air and sun much of the day when it can lose a good portion of its water yet still photosynthesize.  Its sporophyte looks identical to its gametophyte (the generations are isomorphic). 
 

Chondracanthus exasperus
Turkish Towel
Southeast Alaska to Baja California
Family Gigartinaceae

This red alga sometimes washes up on the beach between Netarts and Oceanside and can be found growing in the cobbled shallows just south of Happy Camp in Netarts Bay. Its distinctive rough surface reminds one of a bath towel, hence the common name. It has a small discoid holdfast that supports several broad, brick-red to purple-red blades, each of which may reach more than a couple feet in length, and each with a short stipe. Both sides of a blade are covered with small, pimple-like bumps, the papillae, that often, but not always, harbor reproductive structures. The blades of sporophyte and gametophyte generations are isomorphic, which means they look the same and can only be identified by microscopic examination. Early guides place Chondracanthus in the genus Gigartina.

Mazzaella oregona
Northern Mazza Weed
Southern Alaska to Ventura, California
Family Gigartinaceae

The blades of this Mazzaella are irregular, divided, lobed, and often covered with large bumps, the cystocarps, which are reproductive structures common to most red algae. Cystocarps produce carpospores, spores that are diploid (having a double set of chromosomes) and germinate to give rise to free-living individuals, the tetrasporophytes. M. oregona may have a short stipe or it may be sessile. Its color can vary from yellow-brown to reddish brown. It can be common on rocks in wave-exposed habitats, usually in the mid to upper intertidal zone. It was formerly named M. heterocarpus and Iridaea heterocapus, names you may find in older seaweed guides.
 

Mazzaella parksii
The Horn of Plenty Alga
Aleutian Islands, Alaska to northern California
Family Gigartinaceae

Until recently known as M. cornucopiae, the horn of plenty alga lives between the Capes in the wave-pounded rocks of the middle-to-high intertidal zones where it forms a dense turf of curled, often lobed blades usually less than two inches long. They propagate vegetatively from a perennial encrusting holdfast, and, if broken apart from the rest of the thallus, can survive on their own. Because of this potential for independence, M. parksii is known as a “clonal” alga. The blades range in color from a light yellow-green (as shown here) to a brownish-purple. Its vertical distribution in the intertidal zone is determined by physiological stress in it upper reaches – heat and desiccation – and by herbivores such as snails at its lower limit. It prefers north-facing slopes which avoid direct sunlight. It can also be found in the western Pacific from Japan to Eastern Russia.
 

Mazzaella splendens
Iridescent Seaweed, Rainbow Leaf
Southeast Alaska to Baja California
Family Gigartinaceae

This leafy red seaweed is easily identified when wet by its iridescent sheen. It shows rainbows of blues and reds against its natural wine-colored background. The iridescence is caused by the selective reflection of white light by the varying thicknesses of a cuticle on the surface of the blade, much in the way a film of oil on water becomes iridescent. It is found in both in wave-prone and sheltered rocky habitats, usually in the mid intertidal to subtidal zones. Those pictured here were photographed under water at Netarts, near the mouth of the bay.

This alga and other reds contain a carraeenan, a gelatin-like substance in its cell walls that is extracted for commercial purposes and used as a smoothing and thickening material in toothpaste, ice cream, puddings, paints, and other products. 

Carrageenan can also be used in identification of the alga’s isomorphic reproductive phases.  Mazaella spendens has isomorphic gametophyte and tetrasporophyte stages that are difficult to visually distinguish but can be characterized by several kinds of analyses, one of which is a simple colorimetric chemical test. The chemical, resorcinol, a phenolic compound, is used to identify different kinds of carrageenans (kappa-carrageenan in the gametophyte and lambda-carrageenan in the tetrasporophytes). 

Tetrasporophyte and gametophyte phases can form their own populations that vary with seasons, the amount of shelter from or exposure to surf, and other factors. Studies of the environmental influences that cause the dominance of one phase over the other rely on this kind of analysis.
 

Callophyllis sp.
Violet Sea Fan
Alaska to Baja California
Family Kallymeniaceae

This is one of those leafy red algae that are difficult to identify in the field. The surest way to determine the genus is to examine a thin cross section of the blade with a microscope. The medulla (the inner core of the blade) of Callophyllis has large cells dispersed among chains of small cells. The Callophyllis pictured here is probably C. flabellulata. Macroscopically, the blades are not fleshy, have no midribs or veins, no stipe, but do taper into a discoid holdfast. The ends of the blades have rather ragged branches or notches. It grows locally on rocks in the mid to lower intertidal zone. 

Mastocarpus papillatus
Turkish washcloth
Queen Charlotte Islands, British Columbia to southern California
Family Petrocelidaceae

Mastocarpus papillatus has a complex life history that puzzled phycologists until the 1970s when the alga was cultured and the various reproductive stages, which do not resemble each other, were identified. The stage pictured here is the female gametophyte. It is dark red-brown to almost black. The blades are dichotomously branched, covered with papillae, and grow up to 6 inches long. The papillae, the small bumps on the surface of the blades, are cystocarps which give rise to carposporophytes that have their own morphology. The male gametophyte has no papillae, is yellow to light pink, and has a thinner blade. The most confusing stage is the tetrasporophyte, once thought to be a different alga altogether called Petrocelis franciscana. It is encrusting and looks like a patch of soft tar on a rock. Once the life cycle was worked out, it became the “Petrocelis stage” of Mastocarpus papillatus, but is now just called the tetrasporophyte. This alga lives in the mid to high intertidal zone. It can undergo considerable desiccation, and it can withstand high temperatures. Locally, it is common on the rocks on the south side of Short Beach, near the north entrance to Lost Boy Cave.

(see http://www.mbari.org/staff/conn/botany/reds/mastocar/taxonomy.htm for more on the life history and morphologies).
 

Ahnfeltiopsis linearis
Flattened Ahnfelt’s Seaweed
Southern British Columbia to Point Conception, California
Family Phyllophoraceae

Named after a Swedish botanist, Nils Otto Ahnfelt, this cartilaginous-feeling, dichotomously branched seaweed inhabits tops and upper sides of the lower profile, sand-impacted rocks in the middle intertidal zone, especially along Tunnel Beach. It branches primarily in a single plane, making the thallus rather fan-shaped. Its outer branches are slightly flattened, rather oval in cross section, but the base of the thallus is round. It can be a deep maroon near the base, but lighten after the second dichotomy. The tips of older thalli may bleach to almost white. Its holdfast is disk-shaped and unbranched. Tunnel Beach is part of a pocket beach where the sand moves in and out, sometimes covering rocks, other times exposing them. Ahnfeltiopsis is frequently buried and can remain alive under the sand for over six months. This seaweed used to be known as Gymnogongrus linearis. 
 

Halymenia schizymenioides (?)
No Common Name
Washington to Southern California
Family Halymeniaceae

This is another of those leafy red seaweeds that are difficult to identify in the field. Microscopic examination of a cross section of the blade revealed that the medulla was composed of randomly arranged filaments. Filaments are characteristic of Halymenia, and the random arrangement suggests that the species is schizymenioides (See Gabrialson, et. al., p72). The blades are broadly lanceolate, the holdfast is discoid, and it attaches to rocks. This specimen was collected from Tunnel Beach in the lower tidal zone.

Prionitis linearis
No Common Name
Southern Alaska to Baja California
Family Halymeniaceae

This mid-to-low intertidal red alga seems to be fairly rare locally, but can be found sometimes along Tunnel Beach and Lost Boy Beach. There is little information on this seaweed on the internet, and I found it only in two current seaweed guides: Abbott and Hollenberg’s Marine Algae of California and Gabrielson et al’s Keys to the Benthic Marine Algae and Sea Grasses of British Columbia, Southeast Alaska, Washington and Oregon.  The wiry thalli may be 12 inches long or more, dark red in color, somewhat dichotomously branched with the ends of the branches frequently flattened. It is saxicolous (attached to rocks) but lives in areas impacted by sand. 

Prionitis lyallii
Bleachweed
Southern British Columbia to Baja California
Family Halymeniaceae

Prionitis lyallii is common during summer around the edges of tide pools. Branching is not dichotomous. Its flatted secondary blades can be more than an inch wide, generally wider than the primary blades. They may be decorated with small, tertiary, pinnate outgrowths. Its color can range from dark red to a light brownish-yellow as pictured here. It may smell like household bleach. It is morphologically diverse, and its form may vary with geography.
 

Gracilaria / Gracilariopsis
Red Spaghetti, Sea Spaghetti
Alaska and Canada to Mexico
Family Gracilariaceae

Gracil (Latin) means thin or slender. These two genera of spaghetti-looking algae can only be identified by their reproductive structures, for example whether the spermatangia of the male alga are in pits or whether they are borne in a continuous superficial layer of the thallus. This kind of examination requires a microscope. For this reason, most field guides, as will this one, group these two genera together. The two probable species that may occur in our area are Gracilariopsis sjoesedtii and Gracialria pacifica.

Examples shown here, one lying on the beach (upper photo), the other in shallow water, were growing attached to cobbles buried in sand near the entrance of Netarts Bay. The holdfast is small and discoid. The thallus is reddish when young but turns yellow-brown as it ages. 

Gracilaria textorii var. cunninghamii
Kabonori
Distribution?
Family Gracilariaceae

Not all Gracilaria are round and spaghetti-like. Some are flat. The blades of Gracilaria textorii are uniformly flattened and dichotomously branched. The medulla is composed of large, similarly-sized cells. The raised bumps on the thallus shown in the photographs are probably cystocarps. The holdfast is discoid, and the alga grows on rocks. This specimen was collected near the entrance of Netarts Bay. The variety cunninghamii is described in the “Marine Algae of California” by Abbott and Hollenberg, but in few other guides. I could find little information on its geographic range. Gracillaria textorii var. tenuis is common in the Western Pacific where in Japan it is known as kabonori. 

Plocamium cartilagineum (pacificum)
Sea Comb
Southeastern Alaska to Baja California
Family Plocamiaceae

This deep pink to rose-red alga is common on upper and lateral surfaces of rocks in the mid to lower intertidal zone and will extend into subtidal regions. It is abundant at Tunnel Beach where it tolerates being covered by sand. It has a flattened, cartilaginous thallus with successive branchlets, the outer ones branching from one side only, like a comb. Many of the branchlets are slightly curved (the genus is derived from the Greek word “plokos” meaning “curl”). It often grows from prostrate stoloniferous branches.

There is some debate about the correct species name. P. cartilagineum occurs in Europe, the Indian Ocean and other places around the world, and it is argued that because of confusion in the history of name and morphological differences between the alga that grows here and P. cartilagineum elsewhere, the North Pacific Coast species should be P. pacificum, not P. cartilagineum (http://www.nilauro.com/plocamium/taxnomen.htm). Lamb and Hanby in their book “Marine Life of the Pacific Northwest” compromise by calling it Plocamium cartilagineum subsp. pacificum.

Several types of chemicals called halogenated monoterpenes have been isolated from P. cartilagineum which have insecticidal properties against aphids, tomato moths. These compounds are also being investigated for antimicrobial activity as well as cancer treatments.
 

Ahnfeltiopsis gigartinoides
Loose Ahnfelt’s Seaweed
Alaska to Mexico
Family Phyllophoraceae

A. gigartinoides has a crustose sporophyte (tetraporophyte) and an upright gametophyte. The semi-dichotomous branches are narrower and more rounded than it intertidal counterpart, A. linearis. It is attached to rocks in the lower and sub-tidal zones and is often buried in sand. It is dark red to almost black. It may grow up to ten inches tall.

Callithamnion pikeanum
Beauty Bush
Alaska to California
Family Ceramiaceae

You can find beauty bush high in the intertidal zone, the splash zone, on rocks at Tunnel Beach and Short Beach. It is easy to recognize by its wooly appearance due to its dense branching. It is a filamentous red whose main axis is heavily corticated, and there may be several axises arising from a common holdfast. It is described as being colored from purplish brown to tan and up to sixteen inches long. In our area it seems to be tannish and mostly one to three inches long. Tetrasporangia form on the upper sides of the outer filaments, the side toward the axis. They are sessile, that is, they have no stalks. The generic name is from Greek meaning “beautiful shrub”.