Friday, April 8, 2016

Desert flowers

The last two posts have focused on desert ferns, but it's only fair to share some photos of the incredible flowers we saw too. Thanks to above average rainfall this spring, the desert was truly in bloom, and we caught the end of a major flowering of cacti and desert annuals. Here is a small sampling of what we saw.

First, an assortment of cacti:

Next, a classic feature of the Sonoran and other southern deserts, Ocotillo (Fouquieria splendens)

A beautiful Yucca and a few other flowers:

Phoradendron californicum, a mistletoe
Member of Malvaceae, the cotton family
Palafoxia sp., member of the sunflower family, Asteraceae
Funastrum cynanchoides, a vining milkweed
Epipactis gigantea, an orchid!

Monday, April 4, 2016

Desert ferns: not Myriopteris

My last post focused on several species of Myriopteris ferns we found in the Anza Borrego desert region of southern California. In addition, we found a few other species of ferns that also deserve highlighting. These included Pellaea mucronata, Pentagramma triangularis, and Adiantum capillus-veneris, all members of the family Pteridaceae (like Myriopteris). Adiantum was a particularly pleasant surprise because it is not a particularly desert-adapted fern at all. We found it at the end of a long hike up Hellhole Canyon in Anza Borrego Desert Park, at the very aptly named Maidenhair Falls. Clearly the ferns survive in that location thanks to the waterfall!

Pellaea mucronata
Pellaea mucronata and Myriopteris viscida
Pentagramma triangularis
Pentagramma triangularis
Adiantum capillus-veneris
Adiantum capillus-veneris
Last but not least, we found a signature desert lycophyte, Selaginella eremophila. This one is nice and green, probably thanks to some recent rains that brought it back to life. Many Selaginella species are resurrection plants, able to dry out completely and rehydrate quickly when water becomes available again. Most of the ones we saw were brown and crispy; this one was a lucky find. I previously blogged about Selaginella and their resurrection abilities here.

Selaginella eremophila

Tuesday, March 29, 2016

Desert ferns: Myriopteris

I spent most of last week in the desert southwest of the U.S., visiting Anza Borrego Desert State Park in southern California. I went as part of a Desert Ecology course offered through the UW-Madison Botany Department, my PhD alma mater, and led by my PhD advisor Tom Givnish and the department's new plant physiological ecologist, Kate McCulloh. We spent the first part of the week exploring Anza Borrego and the Borrego Springs area, taking field trips as far away as the Salton Sea, Joshua Tree National Park, and Mt. San Jacinto.

You've probably heard that this year is an El NiƱo year, which has resulted in excess rainfall in this part of the country, and a rare "superbloom" in areas like Death Valley. The flowers were also out in full force in the Anza Borrego area, and we had a wonderful time learning to identify the desert annuals that were in bloom and thinking about their ecology and relation to the landscape. But of course, for me there was another highlight - the ferns! There is actually a large radiation of ferns in the desert southwest, with a suite of adaptations for living in this often punishing environment. We managed to find six species of ferns during our few days there, which isn't a bad haul.

Three of the species we found belong to the genus Myriopteris, a classic xeric-adapted group of ferns in the family Pteridaceae. Many of the members of this genus formerly belonged to the genus Cheilanthes, but a beautiful recent study by my fern friend Amanda Grusz, currently a postdoc at the Smithsonian Institution, revealed that the ferns now called Myriopteris all form a clade, and should therefore be named accordingly. You can find Amanda's great paper on the evolution of this genus here.

The three species we found are Myriopteris covillei, M. parryi, and M. viscida. In the photos below, you can see some of these ferns' adaptations for desert living, including small stature, and being coated with a dense layer of hairs and/or scales, to slow water loss. They also tend to live in rocky cracks and crevices out of direct sunlight.

L to R: M. parryi, M. covillei, M. viscida
Myriopteris viscida
Myriopteris covillei
Myriopteris covillei
Myriopteris covillei
Myriopteris covillei
The M. covillei pictured above were found hiding out under these huge rock formations in Joshua Tree
Myriopteris parryi
Myriopteris parryi 
Myriopteris parryi
Myriopteris parryi
Myriopteris parryi
The desert just feet away from this population of M. parryi!