The Strangest Wood Sorrel

Photo by Yastay licensed under CC BY-SA 4.0

Photo by Yastay licensed under CC BY-SA 4.0

For me, wood sorrels are a group of plants I usually have to look down to find. This is certainly not the case for Oxalis gigantea. Native to the coastal mountains of northern Chile, this bizarre Oxalis has forgone the traditional herbaceous habit of its cousins in exchange for a woody shrub-like growth form.

Photo by Jardín Botánico Nacional, Viña del Mar, Chile licensed under CC BY-NC 2.0

Photo by Jardín Botánico Nacional, Viña del Mar, Chile licensed under CC BY-NC 2.0

When I first laid eyes on O. gigantea, I thought I was looking at some strange form of Ocotillo. In front of me was a shrubby plant consisting of multiple upright branches that were covered in a dense layer of shiny green leaves occasionally interrupted by yellow flowers. You would think that at this point in my life, aberrant taxa would not longer surprise me. Think again. 

Photo by Marcelo_Bustamante licensed under CC BY-NC-ND 2.0

Photo by Marcelo_Bustamante licensed under CC BY-NC-ND 2.0

O. gigantea is one of the largest of the roughly 570 Oxalis species known to science. Its woody branches can grow to a height of 2 meters (6 feet)! The branches themselves are quite interesting to look at. They are covered in woody spurs from which clusters of traditional Oxalis-style leaves emerge. Each stem is capable of producing copious amounts of flowers all throughout the winter months. The flowers are said to be pollinated by hummingbirds but I was not able to find any data on this. 

Photo by Claudio Alvarado Solari licensed under CC BY-NC 2.0

Photo by Claudio Alvarado Solari licensed under CC BY-NC 2.0

This shrub is but one part of the Atacama Desert flora. This region of Chile is quite arid,  experiencing a 6 to 10 month dry season every year. What rain does come is often sparse. Any plant living there must be able to cope. And cope O. gigantea does! This oddball shrub is deciduous, dropping its leaves during the dryer months. During that time, these shrubs look pretty ragged. You would never guess just how lush it will become once the rains return. Also, it has a highly developed root system, no doubt for storing water and nutrients to tide them over.  

Photo by Jardín Botánico Nacional, Viña del Mar, Chile licensed under CC BY-NC 2.0

Photo by Jardín Botánico Nacional, Viña del Mar, Chile licensed under CC BY-NC 2.0

O. gigantea has enjoyed popularity as a horticultural oddity over the years. In fact, growing this shrub as a container plant is said to be quite easy. Despite its garden familiarity, O. gigantea is noticeably absent from the scientific literature. In writing this piece, I scoured the internet for any and all research I could find. Sadly, it simply isn't there.

This is all too often the case for unique and interesting plant species like O. gigantea. Like so many other species, it has suffered from the disdain academia has had for organismal research over the last few decades. We humans can and must do better than that. For now, what information does exist has come from horticulturists, gardeners, and avid botanizers from around the world. 

Photo Credits: [1] [2] [3] [4] [5]

Further Reading: [1] [2] 

 

The Truth About Clover

Photo by loriejeanne licensed under CC BY-NC-ND 2.0

Photo by loriejeanne licensed under CC BY-NC-ND 2.0

Irish or not, four-leaf clovers are ingrained in our culture. They are a symbol of good luck and finding one is quite exciting. When one speaks traditionally about finding a four-leaf clover they are usually referring to a member of the genus Trifolium, which is a genus of true clovers in the legume family. As the generic name suggests, true clovers typically exhibit leaves of three. 

The odds of finding a four-leaf clover is roughly 1 in 10,000. You stand the best chance of finding them in patches of either white clover (Trifolium repens) or red clover (Trifolium pratense), which are actually native to parts of Europe and Africa. The mutation doesn't stop at four leaves either. Clovers with five or more leaves have been found and the world record for most leaves on a single clover is 56! What causes this mutation is a bit of a mystery. Some feel that it is environmental while others feel it is the result of recessive genes. A study done on white clover lends some support to the genetic connection. 

I find it interesting that some of the most the famous depictions of four-leaf "clovers" are not clovers at all but rather varieties of Oxalis tetraphylla. This Mexican species produces leaves divided into four with the characteristic lobe-like shape. Since it only ever produces four leaves, it is a failsafe for those looking to add a bit of "luck" to the season. 

Photo Credit: loriejeanne (http://bit.ly/1ibEJfy)

Further Reading:

https://www.crops.org/publications/cs/abstracts/50/4/1260

http://www.sciencebase.com/science-blog/five-leaf-clovers.html

http://news.nationalgeographic.com/news/2009/05/photogalleries/week-in-news-pictures-130/photo4.html