Mormons used the plant to make a caffeine-free hot drink, and Native Americans used it to relieve congestion

As spring swells and climbs through the canyons of the Colorado Plateau, green ephedra, also called Mormon tea, Ephedra viridis, produces arrangements at its branch nodes, and they produce tiny yellow structures that some people might presume are flowers. Ephedra is quite common in some habitats, so this show can be stunning.

But those yellow excrescences are cones, not flowers.

Ephedra is an ancient genus, with fossils reaching back 125 million years and it is a gymnosperm, not an angiosperm. That is, it is more closely allied with pines, spruces and firs than angiosperms such as daisies or aspens. 

Green ephedra is a dioecious species, meaning that an individual produces either male cones or female cones. The male cones form at the nodes of stems, and they sprout microsporangia, which release wind-dispersed pollen. 

The microsporangia are those yellow things that some people (including me) first take as flowers. Females bear macrosporangia, which, after pollination, produce seeds. Female cones, which are larger than male cones, have more muted colors. 

Green ephedra grows as a shrub, usually 1 to 5 feet tall. It roots form rhizomes, which allow it to spread asexually, forming small, dense clusters of shrubs. Its base and branches are woody, and their green stems grow straight up, branching as they grow. Cones are formed at the branch nodes. Ephedra species have tiny, vestigial leaves that appear pigmented but quickly degenerate to dark scales. The conspicuous green stems are photosynthetic.

Approximately 70 Ephedra species are extant, and they are distributed around the world. Three species grow on the Colorado Plateau—green ephedra, E. viridis, Cutler's Mormon tea, E. cutleri, and Torrey's Mormon tea, E. torreyana. E. cutleri typically grows only 2 feet tall, but in mats 10 to 15 feet in diameter. E. torreyana can be identified by its blue-grey-green foliage, intertwined (not parallel and upright) stems and by three leaves in a whorl, rather than two.  

Male and female E. viridis are not distributed randomly in patchy habitats. Males are more common on dry sites, while females are about four times abundant as males in relatively mesic sites. 

One can see an evolutionary explanation to this partial specialization, which is shared by four other dioecious species living in arid lands in the west. The hilltops and ridges are relatively dry because they catch the wind and are well-drained, so they are optimal for releasing wind-borne pollen. Nearby bottomlands may have ephemeral streams or ponds. Females need more water than males for their prolonged nuturing of developing seeds in the dry summer heat.

Ephedra is browsed by pronghorn antelope, mule deer, elk, buffalo and horses. Male sheep and cows browse it with no problems, but if pregnant cows or sheep eat it, they die or suffer prolonged discomfort. 

Mormons steeped dried ephedra stems to make a caffeine-free hot drink, and Native Americans used an ephedra tea to relieve congestion. 

Several thousand years ago, strong pharmaceutical activity was found in E. sinica, which is native to China. The active chemical compound was named ephedrine, and it was used in the United States in the 1950s as an effective treatment for asthma. 

Unfortunately, ephedrine was engineered by resourceful chemists to produce an amphetamine, known on the streets as crystal meth. The species in North America do not synthesize ephedrine.

Although all the Ephedra species in North America are wind pollinated, two of the species that evolved earlier than other extant species are pollinated by insects. E. foeminea is one of the species relying on insects, but it also needs the light of a full moon to achieve pollination. 

A study of pollination biology in Greece and Croatia recorded the production of the pollination droplet, which appears at the tip of the female cone and facilitates movement of the pollen into the cone. 

The pollination droplet appears on the night of the full moon in E. foeminea, but pollination droplets are not synchronized with full moons in a sympatric, wind pollinated E. distachya. 

Apparently, E. foeminea can accurately anticipate the date of the full moon to optimally pump out the pollination droplet. The investigators of this study mentioned that, in a dry habitat in the Balkans on the night of a full moon, the many pollination droplets "glitter like diamonds in the full-moonlight." E. foeminea does not produce nectar or a fragrance—insects rely on the light of diamonds to deliver their pollen.