Polanisia dodecandra trachysperma

Clammyweed - Polanisia dodecandra trachysperma
Warm Springs Wash
Hillsboro, New Mexico, USA

Clammyweed (a.k.a. Red Whisker Clammyweed), Polanisia dodecandra, is a common plant in washes and hillsides in our area at lower to middle elevations.  It is common around Hillsboro.  

It is found in nearly all of the lower 48 in the United States, southern Canada, and northern Mexico.  There are three subspecies of this plant, two may be found here (the nominate form and P. d. trachysperma).  P. d. trachysperma (Sandyseed, Western Clammyweed, or Large-flowered Clammyweed) is the more likely form to be found in this area.  John Torrey and Asa Gray first described P. d. trachysperma as a full species (P. t.).

The species derives its common name from its “sticky” nature, created by surface glands.  Linnaeus listed it as Cleome dodecandra and it is often referred to as “Cleome”.  The subspecies most likely here has a synonym of Cleome trachysperma.

As seen in these photographs, the seed pods are quite large (up to 3” long) for a plant that seldom grows to more than 2’ in height.  The pods only open at the top, note in photograph below.

 


© Robert Barnes 2018