Alexis authored today's entry:

Eric Hunt (Eric in SF@Flickr) submitted his two photos of green ephedra (photo 1 | photo 2) taken in the Alabama Hills of California. Thanks for sharing, Eric!

Ephedra viridis, commonly called green ephedra or green joint-fir, is an erect shrub growing to approximately 1.2m (4ft) in height. The species is found in the western US states of New Mexico, Arizona, California, Colorado, Utah and Nevada. Ephedra species belong to the Gnetophyta, a taxonomic division of plants (compare with Pinophyta, the conifers, or Magnoliophyta, the flowering plants). As the Gnetophyta have some characteristics that are found in one or the other of Pinophyta and Magnoliophyta, some hypotheses suggest the group is an evolutionary link between conifers and flowering plants.

This dioecious species is both resistant to drought and winter-hardy. Because the stems can still be found sticking up through layers of snow, it is an important food source for large game animals in the winter. Often found growing on limestone, green ephedra is adapted to dry, rocky, open sites where the soils are coarse and very well-drained.

Traditionally, North American First Nations used the stems of Ephedra viridis to make beverages, including a medicinal tea for the treatment of back pain. Furthermore, the seeds could be brewed to make a coffee-like beverage, or ground to make flour. Ephedra species are sometimes known as Mormon tea; early Mormon settlers reportedly drank beverages made from Ephedra in the place of regular coffee or tea.

Today's photograph is courtesy of Douglas Justice, who captured this image a couple weeks ago in the Alpine Garden.

I'm fairly certain there isn't an English common name for this species. While researching this species yesterday due to some confusion over its scientific name and description, we (Douglas, Eric and myself) learned that little work had been done on the taxonomy of the genus Ephedra since the late 19th century. Some modern work has occurred in the past fifteen years or so, but it certainly hasn't trickled into the horticultural literature yet. Of the older horticultural texts we examined, it seemed like the descriptions of Ephedra were all slight variations from the late 19th century work. Ephedra has often been regarded as having little ornamental value, though perhaps that will no longer be true with changing tastes or the propagation of exemplary species.

This plant is presently labelled in the garden as Ephedra americana var. andina. Most information in books (what little there is) will be under that name, though it is now treated as a synonym of Ephedra chilensis. Both names, however, hint at the current distribution of the species: the Andean (andina) mountains of Argentina and Chile (chilensis).

If you'd like to read more about Ephedra, you'll likely find search engine results filled with commercial sites. Instead, I suggest visiting a previous entry on BPotD, Ephedra frustillata.

I've covered most broadly-defined groups of plants on Botany Photo of the Day in the past two-plus years. However, here's a representative of one group that I've neglected to date, the gnetophytes.

Traditionally, seed-bearing plants were thought to be divided into two groups: the angiosperms (flowering plants with seeds developing within a carpel) and gymnosperms (non-flowering plants with seeds developing naked on the scale of a cone or equivalent). While the angiosperms remain a phylogenetically-sound group (i.e., all derived from a common ancestor), the gymnosperms are now thought to be an artifical grouping. In other words, we use the term gymnosperms for non-flowering seed-bearing plants because it is convenient to do so and not because it reflects a common-ancestor evolutionary relationship among the plant groups with those qualities.

The gnetophytes, including the genus Ephedra, are one of four groups traditionally thought of as gymnosperms (the other three being conifers, cycads and ginkgos). However, they differ from the other three groups in that they contain vessel elements, a cell type found in the water-conducting tissues. Interestingly, vessel elements are commonplace in the flowering plants. The presence of vessel elements in the gnetophytes has long been held up as one of the hints that the gymnosperms are an artifical grouping, with the corollary that the evolutionary relationships among the groups is more complex than it seems at first glance.

Ephedra is typically distributed across the northern hemisphere, but Ephedra frustillata is one of the exceptions. It is found in Tierra del Fuego as well as mainland Argentina and Chile (here's a photo of it in habitat). The macro photograph shows the pollen-producing male cones in detail (and they were producing heavily; the legs of my tripod were painted yellow after taking these images).