Astagalus geyeri var. geyeri

Geyer's milkvetch

Fabaceae

Found in Deep Springs and Fish-Lake Valley, Geyer's milkvetch is an easily overlooked plant. Standing barely 5 cm at its tallest, this small pea is among the numerous special status plants found in the California Desert District.

This milkvetch appears to be associated with blow sand habitats. They are found abundantly along a southern chain of dunes in Deep Springs valley, but sharply cut off the moment one leaves the blow sand and enters more rocky habitat. I found that these tiny plants, at first very easily overlooked, were quite prolific in their "chosen" area, to the point that while surveying for them, I often had to avoid stepping on them as I worked my transect lines. In the short time I worked the area, I found over 500 plants.

This plant is a further reflection of how a special status plant can vary in nature. Unlike some of its cousin Astragalus', where it is often possible to actually count the number of individuals in the whole population, this species is quite prolific, but is highly limited to a small section of land. It is this limited range of habitat that makes this as a species of concern to the Bureau of Land Management. If something were to happen to the site where the species is found, then it could easily wipe out one of the few known populations. Because of this, the BLM does not allow utilization of the lands where this plant is found.

Astragalus ertterae

Walker pass milkvetch

Fabaceae

There are plants in the Mojave that have very wide distribution, and there are some that have extremely limited ones. One of the later, in fact, one of the most extreme cases, is the Walker Pass Milkvetch, a member of the pea family. The entire known, and confirmed population of this plant is limited to a handful of individuals located on one section of the Pacific Crest Trailnorth of Walker Pass. The original site records only showed 1 plant, but in recent years, there has been some recruitment, and now the population has exploded to 14 plants.

This extreme endemism is an example of how limited in distribution a plant species can be. And the fact that the entire population is located directly adjacent to a regularly traversed hiking trail may seem like a concern. However, the obscurity of the plant is its shield in this case. Yes, there may only be 14 of them, but most people are walking the PCT are not climbing the banks, which is where the plant grows. Still, like all rare plants, there is some degree of danger to it, since it has such a limited known distribution. In all likelihood, there are other populations, which have, thus far, not been identified.