Chondracanthus exasperatus

Another new writer today: Cora den Hartigh is a Botany Photo of the Day work-learn student. Like Tamara, Cora is joining us for at least the next six months. For her first entry, Cora writes:

Instead of land plants, here is something associated with the ocean courtesy of mycologie@Flickr (original photo). Thank you for the refreshing splash of maroon!

This resplendent red macroalgae is known as Chondracanthus exasperatus, or Turkish towel, and it is a rather common species along the Pacific coast of North America from Alaska to Mexico. Its rich colour is due to phycoerythrin, an accessory pigment that works in tandem with phycocyanin to facilitate light harvesting at depth. When wet, Chondracanthus exasperatus may take on iridescent tinges not unlike the stunning Mazzaella splendens (previously known as Iridaea splendens,which I personally think was a very lovely name). The iridescence is akin to the rainbows caused by oil or gasoline in water – in fact, layers of oil or cuticle in these seaweeds are indeed what refract light differently, reflecting various colours. It is particularly difficult to capture this refraction and reflection in a single photograph. It is easier to see in-person or with a video like this one, from a diver who chose to record the underwater shimmer! If you are interested in learning about a few other types of seaweed along the western North American coast, see An Introduction to the Seaweeds of British Columbia, an excellent overview written by UBC graduate Colin Bates.

Back to Chondracanthus exasperatus! Preferring lower intertidal zones, this raspy algae attaches to rocks with a disc-shaped holdfast, sort of like an anchor. Its long leaf-like blades can grow over a meter long and often wash up after storms, to the delight of the discerning beachcomber! Papillate blades of Chondracanthus exasperatus have excellent exfoliant properties and can be used in the bath or shower in lieu of a loofah (hence the common name). These bumpy papillae are quite variable; this photograph demonstrates some marvellous undulation, as opposed to the coarser textures that might indicate a vegetative state. Both antibacterial and high in carrageenan (also a food thickener), these natural scrubbies are often sold as beauty aids. I myself have attempted to gift precious specimens of this seaweed in the past, but the recipient was not impressed: “Ick! It smells like saltwater! You think I’m going to use THAT in the shower?!” Despite my assurances that the algae’s cells were highly saline, would burst when faced with fresh bathwater, would disintegrate after about three or four days, and would never clog plumbing, my words were not convincing. Perhaps you will appreciate Turkish towel’s ocean charms!

Can’t get enough seaweed? Bamfield Marine Sciences Centre’s OceanLink has a helpful page on algae of the red persuasion, and their overview of seaweeds is a valuable resource too!

Chondracanthus exasperatus

9 responses to “Chondracanthus exasperatus”

  1. Wendy Cutler

    Welcome to Cora! How nice to have you here. Looks like we’re in for another great six months.

  2. Karthik

    So, what is the exasperating part of this seaweed? 🙂
    One meaning Wiktionary gives for “exasperatus” is “roughened”. Is that the meaning here?

  3. chris

    i know, i keep telling people how you can use YuccA GLAUCA for shampoo and how nice it makes hair look and they don’t believe me

  4. Bonnie

    Very cool! As the picture scrolled slowly up my screen I thought it was some kind of chili dish, garnished with pistachios!

  5. michael aman

    Oh, Cora! I find your writing style refreshing. I anticipate enjoying the human touch you may bring to what (sometimes)is a rather dry listing of plant facts. I hope no one discourages you from the use of personal observation along with whimsy and humor. Welcome!

  6. kestrelsparhawk

    This is really beautiful. all the years I lived in the Northwest, and I never thought to notice the seaweed lying around. I need to remedy that. Thank you!

  7. Richard Old

    Cora: If this informative and highly enjoyable write-up is any indication of what we can expect over the next six months, we are all in for some real treats!!!!
    Welcome and best regards,
    Richard R. Old, Ph.D.

  8. stuage

    Wicked entry!
    Just curious: would the Chondra in the first part of the genus name refer to the moon, by chance??

  9. Daniel

    For some reason, an update of the software is preventing some comments.
    Ann K. sent this one along:
    “Welcome, Cora. I too appreciate the humour and personal observations. Colin Bates’ Introduction to Seaweeds is a much thumbed and appreciated book in our family as we love beach rambling. Another favourite reference is North Pacific Seaweeds by Rita M. O’Clair and Sandra C. Lindstrom, Plant Press, Alaska, 2000, which also includes some seaweed recipes.”

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