Botany Photo of the Day
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January 18, 2017: Botany Photo of the Day is being actively worked on. Returning soon!

Carex macrocephala

Carex macrocephala
Carex macrocephala
Carex macrocephala

I've been away for more than three of the past four weeks, so I'm grateful for all of the work that Taisha has been doing for BPotD. She's also been involved in some balloon photography of the Garden recently: Aerial Photos of the Garden and Lift Off!

Several weeks ago, I visited Haida Gwaii for the first time. I'd been too busy leading up to the trip to make daily plans for the vacation, so spontaneity and a bit of randomness were the themes. A chance conversation on one of the small ferries led to meeting one of the archipelago's park rangers, Chris. Several days later, when conditions were optimal, I followed him out via vehicle along North Beach to the Rose Spit Ecological Reserve. Rose Spit ER is surrounded by Naikoon Provincial Park at the northeast corner of Graham Island. This isn't normally a trip a tourist would do without a long hike, so I was glad to be accompanied by someone experienced (here's a warning from the Haida Gwaii Tourism Advisory Committee (PDF): "It is common to see ATVs, trucks and cars being driven along North Beach. The use of motorized vehicles is permitted in Naikoon Park, but only on the shoreline. Vehicles often get stuck in the sand, and are occasionally swallowed by the rising tide before they can be pulled out. TLC Automotive Services in Masset keeps a photo log of swamped vehicles which they are happy to show to visitors..." The driving part of the trip was thankfully uneventful, so I had plenty of time to help Chris locate some of the populations of rare plants in the area and photograph.

Carex macrocephala, or big-headed sedge, isn't considered rare in British Columbia, but it does grow in association at this location with some plants that are. In the third photograph, a token big-headed sedge plant makes an appearance along with the provincially red-listed Lathyrus littoralis and the blue-listed Senecio pseudoarnica. I have better photos of both of these, though the Lathyrus was nearing the end of flowering and the Senecio only had a few individuals starting to flower.

Big-headed sedge has an amphipacific distribution, natively occurring along coastal sandy beaches from Japan, China and Far East Russia to Alaska, British Columbia, Washington and Oregon. A recently-discovered/noticed introduced population also occurs along some of the beaches of New Jersey (see: Carex macrocephala). As noted in that link, the fruits are pointy and sharp; this sedge is not something you would want to step on in bare feet. The second photograph shows that Carex macrocephala occupies the beach zone above the driftwood but below the highest dunes (where Leymus mollis seems to outcompete it). In addition to dispersal by seed, Carex macrocephala forms long underground rhizomes to spread vegetatively.


Readers should be careful not to confuse Carex macrocephala with the exotic Carex kobomugi, which is superficially similar and occurs in the same habitat.

Daniel, I hope you will post many more plant pictures from your trip to Haida Gwaii. I wonder if you found some interesting mosses there too!

Carex kobomugi is so far only reported from the east coast of the USA and Oregon, within North America. This is in addition to its native east Asia distribution.


I can't help thinking what a GREAT calendar that could make!

Interesting about Carex macrocephala finding its way to NJ! I've got to read more on that!

Thanks for this post!

This is such a distinctive species, I had to look it up in my copy of Field Guide to the Sedges of the Pacific Northwest (Wilson et al. [date unspecified]), where there is more information about this very specialized dune sedge, and the threats from Ammophila arenaria, housing developments, and even herbicide treatment because walking barefoot on the perigynia is painful. The mention of look-alike C. kobomugi there does not include a comparative picture. Maybe that could be an upcoming BotPD?
Carl Wishner

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