Notes from South of the Border
Dunes at El Gallito

This section contains entries written for the UC BEE, the monthly newsletter for volunteers and staff of the
UC Berkeley Botanical Garden, about our botanizing in Baja California, and starting in October, 2012.

Click on any photo for a larger image.

BEE FEB 2018

bikeIt seems like this season, I’m on a roll when it comes to different forms of transport to get my botany fix. So far, I’ve hiked, biked and gone out in an SUV and our friend’s dune buggy (nothing off-road, just back roads; see last month’s article). So why not keep up the momentum and try yet another form of transportation? This time, it was a friend’s horse and the destination was the beach.

December 2017 – El Gallito Dunes, Mulegé

Beaches and dunes around the world have been heavily impacted by human activity and natural phenomena. Along Bahía Concepción, which extends from Mulegé about 25 miles southward, there isn’t very much wave action or current and this has resulted in beaches with very flat profiles. Add to that 40-plus years of fishing and tourist activities, including all kinds of vehicles on the beach, camping, and construction, and you end up with hard, flat, sandy areas with very little natural vegetation.

In our area along the Gulf Coast (not inside Bahía Concepción) the prevailing northerly winds have created large, extensive dune fields in several places, and fortunately, most of these are isolated and have not been heavily impacted on a regular basis. One area, on the north side of Punta Chivato extends several kilometers inland and the dunes have well-established vegetation and large areas of stabilized sandy-silty soil. A few roads go through them, but most of the area is inaccessible to motorized activity.

Just south of the Mulegé River, and right at the mouth of Bahía Concepción, are the El Gallito dunes. For years, I've wanted to hike across this area to the base of the small volcanic plug called El Gallito.

Mulege River and Gallito Dunes

Aerial view across the mouth of the Río Mulegé (foreground) into the mouth of Bahía Concepción, with El Gallito dunes. Botanizing by small plane in 2010.

satellite view of dunes

Google Earth image of the beach and dunes. Click to enlarge.

horses waiting

Our steeds await us under a spindly Mesquite early one morning in December.

approaching dunes

My second big challenge nears: staying on the horse as we climb up into the dunes. The first was hauling my creaky self into the saddle.

Dunes

I've not been up in this part of the dune system before. We did some vegetation plots about 4 years ago in a different area where the scrub was very dense and we never made it through to the beach.

Abronia martima

Beach Sand Verbena / Alfombrilla (Abronia maritima, Nyctaginaceae). There are large patches throughout the rear dunes as well as closer to the beach.

dunes

Dune species include many that are gray-green and densely hairy.


Ditaxis serrata var. serrata

Yuma Silverbush (Ditaxis serrata var. serrata, Euphorbiaceae). This is a monoecious species, with separate staminate and pistillate flowers on the same plant. Pictured here is a staminate flower. Baja California plants vary from those in other regions where it is found in that they have unserrated leaves.

dunes

No tumbleweeds here. Just lots of Gulf Crinklemat (Tiquilia cuspidata, Boraginaceae). This is a dominant plant of beach and inland dunes. In drier times, the plant becomes silvery gray in color.

Dune plants

Less active dune with denser ground cover. The silvery plant above center is Psorthamnus emoryi. The grass is the native annual Aristida adscencionis. The shrub on the right is Lomboi.

Psorothamnus emoryi

Dye Bush (Psorothamnus emoryi var. emoryi, Fabaceae) is well-adapted to dune life. Growth is open & airy; the herbage is canescent (densely hairy).

View across dunes towards Mulege

View from up on the dunes at the base of the volcanic plug.


Dunes along trail

Onward to the beach and lighthouse island (Isla Gallo). There are dunes at the base of the small volcanic outcrop to the left.


Beach

A good example of the desert scrub coming right up to the shore. Barclay Saltbush, the gray plants in foreground (Atriplex barclayana, Chenopodiaceae). Shrubs are Lomboi (Jatropha cinerea). For the grass on the right, see the next photo.

Lighthouse island

Marcelo removed the saddles and we rode the horses through the chilly "surf" over to the island. The water level was just below the horses´back. First, and last time riding bareback!

beach dunes

From the beach, we circled around Cerro El Gallito and back to the next beach to the north. A path worn in the dunes by ATVs.


Sesuvium portulacastrum

Sea Purslane is generally found on the foredunes. The herbage resembles other members of the iceplant family. The flower, about 1 cm D, has no petals but rather, the interior surface of the calyx is pink and petalloid.

Spanish needles

Beach Spanish Needle/Coast Palafox (Palafoxia linearis, Asteraceae). In our area, this species occurs only on beach dunes. The leaves are thick, with dense, appressed hairs. Its open branching helps to reduce sun/heat exposure on the dune surface.

Gundlachia diffusa

Sonoran Goldenbush/Hierba del Pasmo (Gundlachia diffusa, Asteraceae). This shrub is common on beach dunes and the edges of coastal wetlands in the southern part of the peninsula.

El Gallito

Looking back at El Gallito and island.

Cenchrus ciliare invasion

Here in the desert scrub between the dunes and the highway, the area is disturbed by livestock and occasional flash floods and being invaded by Buffelgrass (Cenchrus ciliare, Poaceae). This noxious weed spreads rapidly close to the highway and along side roads.

horse
My unenthusiastic mount. Happy to be back
(I think). He closed his eyes and went to sleep.

Gallito dunes

El Gallito dune system (foreground to hill on left)). The transpeninsular highway runs vertically along the right edge. Bahía Concepción and its eastern peninsula can be seen towards the top.

The dunes have always seemed to offer a special promise for botanizing because of their inaccessibility, though there are the occasional ATV riders who just can’t seem to resist ripping up pristine vegetation for a few kicks.

This autumn the dune slopes were visibly bright green from the highway and I really wanted to know what plants were up there. However, for me it was more than I would be able to manage on foot. Walking there one way along the beach is a 4.5 km (2.8 mi) trip. From the highway through tall grass and scrub, then a steep climp into the dunes, it's almost 2 km (1.25 mi). Marcelo's horses seemed the definite way to go, and I was finally physically feeling up to giving it a try.

 

on the trail

It’s been more than 40 years since I've regularly ridden a horse. But, like riding a bike, it comes back to you.

Dune trail

I stayed on, and now up on the dunes, Marcelo continues to lead the way. Nice to just mosey along.

dunes

There was no apparent evidence of livestock and Marcelo says that cattle and horses don't graze here. The dunes were wind-swept and smoothed out.

Abronia maritima

Flowers, leaves and fruit of Sand Verbena. The leaves are thick and leathery, better to retain moisture and survive the hot surface temperature.

dune plants

This small mound has a collection of plants tyicpal to the dunes in our region: Psorothamnus, Ditaxis, Euphorbia, Palafoxia and Cenchrus.

Cenchrus palmeri

Southern Sandbur/Huizapol (Cenchrus palmeri, Poaceae). A really nasty annual native with firm, sharp spines. It is easily dispersed by animals, socks, shoes and tires. The seed germinates inside the bur and takes root. The young bur is red or green, and matures to maroon/black or tan.

Tiquilia cuspidata

Gulf Crinklemat (Tiquilia cuspidata). The leaves are about 3-4 mm L, somewhat thick, densely hairy, and have a sharp tip. The flowers are 6-7 mm D and pinkish-white, pink or dark lavender.

Jatropha cinerea leaves and fruit

Leaf and fruit of Lomboi/Ashy Limberbush (Jatropha cinerea, Euphorbia). The leaves are large, heart-shaped and drought deciduous.

Psorothamnus emory

Orange glands with volatile oils dot the stems, leaves & calyces of Dye Bush, and likely help to deter herbivory by insects & larger animals.

View across dunes to Mulege

I discovered that the bright green color of the dunes as seen from the road was due to the large number of leafy Lomboi shrubs.

Croton californicus

Poking out here & there were clusters of Chuparrosa/Hummingbird Bush (Justicia californica, Acanthaceae). This species is abundant in rear dunes, and to a lesser extent inland in sandy soils.

Beach grass

The small berm (as seen in the previous photo) with a dense population of Seashore Dropseed/Zacate Costero (Sporobolus virginicum, Poaceae). This is the area´s primary beach grass and here it is denser than usual because of limited human disturbance.

Horses on beach

Not much to see on the island for a shoeless botanist, so it was back to the mainland. We all dried off before the saddles went back on and then we climbed aboard for the return loop. Oh, my shaky thighs!

beach dunes

More Seashore Dropseed and Sand Verbena, as well as Sea Purslane/Verdolaga de Playa (Sesuvium portulacastrum, Aizoaceae). ATV tracks on the dunes.

On the beach

This part of the beach, 4.5 km from the river mouth, sees few humans.


Spanish needles

Palafoxia's composite flower heads are discoid (they lack rays) and 10-15 mm D. Each flower tube and the 5 limbs are pale pink, the staminal column is dark purple, and the long, bifurcated stigmas are dark pink.

Gundlachia diffusa

Sonoran Goldenbush/Hierba del Pasmo (Gundlachia diffusa, Asteraceae). Leaves are small and terete. The herbage is tacky, the resin helping to reduce water loss from heat and wind.

Desert scrub

Scrub at the west edge of the dunes is dense and diverse.

Buffelgrass

Coming to the end of the trail and our 6 km round trip.




That's it for this month. I hope to have more interesting plants and sights to share with you next month. Until then, hasta la próxima

Debra Valov—Curatorial Volunteer


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