Browns, Ochrophyta


Below are the brown seaweeds I’ve been lucky enough to find and photograph on Oregon’s exposed rocky shores and, sometimes, washed ashore on the beaches. I’ve organized my examples loosely after Lamb and Hanby (2005), in the order you might encounter them, from highest to lowest in the intertidal. My photos are from northern Oregon unless noted. I refer to AlgaeBase for scientific nomenclature; if I use common names, they’re my choice. Experts cover the seaweeds shown below, and many more, in the easy-to-find resources listed at the bottom of the page.

Let the browns be upon you!

Fucus, rockweed
Fucus grows more extensively (and bigger!) in semi-sheltered places than on surf-swept rocks, where it’s often interspersed with Cladophora, Endocladia, and Pelvetiopsis. It’s common to find drifted Fucus on the beach.

Pelvetiopsis limitata, dwarf rockweed
Pelvetiopsis limitata is at home only on the exposed outer coast, where it can be abundant on the tops of high intertidal rocks. I don’t often find drift Pelvetiopsis on the beaches.

Before leaving Fucus and Pelvetiopsis, here’s a comparative photo of them living together on a high intertidal rock.

Brown cylinders
On northern Oregon shores, brown cylinders, like those shown below, are represented by MelanosiphonScytosiphon, and Hapterophycus. (Any others?) So far, the cylinders I’ve observed remain delicious mysteries.

The five images below are from March on a high vertical wall that gets spray, splash, and a rare winter dunking. From a distance, large patches are distinctly yellowish-brown. Up close, individual cylinders vary from dark yellowish-brown to dark reddish-brown, and some cylinders are noticeably twisted.

The three images in the set below are from late May, in the high intertidal zone. Here, the cylinders are much shorter and redder than the examples above, and there’s not much twisting. In addition, the tufts grow in a matrix of high intertidal Ulva, somewhat isolated from each other, so at a distance, there aren’t visible patches.

The three images in the set below are from late May in a tiny pool on a high boulder surrounded by sand and cobbles. The cylinders are distinctly straw-colored and hollow, and they bear constrictions.

And it’s not unheard of to find drifted straw-colored cylinders on the beach.

In these parts, as far as I know, it’s just P. fascia.

Leathesia marina, sea cauliflower
There are some similar saclike epiphytic browns. This is Leathesia marina. Sea cauliflower can attach to rocks or live as an epiphyte.

Soranthera ulvoidea, studded sea balloon
Soranthera is an epiphyte on Neorhodomela and Odonthalia. It’s not uncommon to find Soranthera on the beach, attached to its drifted host.


Analipus japonicus, fir branch
I haven’t discovered Analipus on the northern Oregon shores I’ve visited. Hence, the examples shown below are from central Oregon, where it’s been easier for me to find. Analipus has many common names; one is bottle brush—my sketch looks like a bottle brush, so I must mention that. Look for Analipus in the mid-intertidal (maybe a little higher or lower).

Postelsia palmaeformis, sea palm
It’s a treat to see stubby sea palms bobbing and poking through wicked surf. They live out on exposed headlands where reaching them is tricky, even at the lowest tides. Detached clumps are fairly common as sea wrack.

Hedophyllum sessile, Sea Cabbage
The accepted scientific name has bounced around a bit. You may see it as Saccharina sessilis. Depending on the age of the blades and wave exposure, it’ll give you different looks. It’s one of the few kelps with no stipe, so that should help with identification. I don’t see much sea cabbage in the drift line.

Egregia menziesii, feather boa kelp
Feather boa is common on mid to low intertidal rocks and not unusual in the drift line. It’s a photo-friendly brown, giving lots of good looks.

Phaeostrophion irregulare, sand-scoured false kelp

Alaria marginata, winged kelp
In exposed places with low rocks and active sand, it experiences seasonal burial. In some of the photos below, you can see the “wings” near the stipe base. Alaria marginata appears in Seaweeds in the Sand.

Laminaria setchellii, split kelp
Laminaria setchellii appeared in Seaweeds in the Sand because, in some places, it experiences seasonal burial. It’s also featured in Kelp Curves because it’s just so dang photogenic.

Laminaria sinclairii, dense-clumped kelp
In northern Oregon, Laminaria sinclairii‘s a good marker for mean lower low water.

Lessoniopsis littoralis
You know you’re on the exposed outer coast when you run into Lessoniopsis littoralis. It also goes by northern tree kelp, for its tree-like look, and strap kelp, for its strap-like blades.

Stephanocystis osmundacea, bladder chain
My home beaches are a bit north of bladder chain strongholds. I only know it from the drift line.

Sargassum muticum, wireweed
Not really at home in exposed surf-swept settings, it can be dense in protected waters and semi-protected pools. Drifted Sargassum is common on beaches.

Desmarestia, flattened acid leaf
I’ll use flattened acid leaf in this entry until I master distinguishing the flattened forms (e.g., Desmarestia ligulataD. herbacea). My examples are from low intertidal rocks or fragments that washed up on beaches.

Below, flattened acid leaf cascades down the rocks among other seaweeds illustrating how limp the blades are. From a distance, the thin, limp blades tend to blend in on the rocks, where they are easy to miss. (As shown below, you will notice them when they lay out on clean sand!)

Closer up, the golden or olive-green blades stand out, but they are likely to mat together, obscuring their fine detail or adding to their beauty, depending on your frame of reference.

Flat acid leaf’s finer details emerge when its branches float in shallow, sand-filled pools.

I’ve often encountered flattened acid leaf in areas of active sand, where it seems tolerant of at least some seasonal burial. Is this its habit, or what’s available on the shores I frequent? Either way, it lays out beautifully on the sand, so I can’t resist showing a few examples.

If you encounter enough flattened acid leaf washed up on the beaches, you’ll notice quite a bit of color and morphological variation. Intriguingly, I’ve seen “color changer” listed among the common names for Desmarestia herbacea, but I don’t know the context.

The examples below have a markedly wide main blade and wide branches with midribs.

Pterygophora californica
Walking or woody-stemmed kelp is mostly subtidal in Oregon. I don’t see it often, even as sea wrack. Those shown here were featured in Browns Put On a Shine in the Drift Line.

Macrocystis pyrifera, giant kelp
My home beaches in northern Oregon are a lot of miles from the nearest Macrocystis beds. I only know it from drift masses washed up on the beaches. Despite the distance, Macrocystis drift is common enough to appear in Common Marine Algae in the Northern Oregon Drift Line: A Gallery of ImagesMacrocystis is featured on the Monterey Bay Aquarium Logo.

Nereocystis luetkeana, bull kelp
Bull kelp is subtidal, pretty much so, but it’s important to intertidal ecosystems as sea wrack. I wrote a little bit about this in Bull Kelp Drift: A Subtidal-to-Surf Zone Connection.

I know Dictyota only as sea wrack.

A Puzzler

How about this one? If you know what this one is, please let me know. Check out the bullae on the blades. The blades are so shiny they inspired Browns Put On a Shine in the Drift Line.

A mystery brown with shiny blistered blades


Abbott, I. A. and G. J. Hollenberg. 1976. Marine Algae of California. Stanford University Press.

Druehl, L. D. and B. E. Clarkston. 2016. Pacific Seaweeds: A Guide To Common Seaweeds of the Pacific Coast. 2nd ed. Harbour Publishing Co.

Harbo, R. M. 2011. Whelks to Whales: Coastal Marine Life of the Pacific Northwest. 2nd ed. Harbour Publishing Co.

Kozloff, E. N. 1993. Seashore Life of the Northern Pacific Coast. 3rd ed. University of Washington Press.

Lamb, A. and B. P. Hanby. 2005. Marine Life of the Pacific Northwest. Harbour Publishing.

Mondragon, J., and J. Mondragon. 2010. Seaweeds of the Pacific Coast. Shoreline Press.

Sept. J. D. 2019. The New Beachcomber’s Guide to the Pacific Northwest. Harbour Publishing.

Web Resources

Friends of Netarts Bay WEBS— Brown Seaweeds page. Accessed 01/30/2023.

Biodiversity of the Central Coast— Brown Algae (Ochrophyta). Accessed 01/30/2023.

Seaweeds of Alaska— Seaweed: Ochrophyta. Accessed 01/30/2023.

Jenn Burt & Tanya Prinzing— Subtidal Kelp Species Field Guide. Accessed 01/30/2023.

The Seaweed Sorter app is fun and very useful!

I updated this page on January 31, 2023


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