Subgenus Chamaesyce


The World Botanical Associates Web Page
Prepared by Richard W. Spjut
May 2004, Oct 2005;  Aug 2006, Dec 2007, Jan 2008, Dec 2013

Chamaesyce albomarginata
Inyo Co.: Hills at north end of Owens
Valley, north of Bishop, CA
Photo by Susan Spjut, May 2006

Chamaesyce albomarginata
Kern Co.: south of California City near junction with Hwy 58, Oct 2007

Chamaesyce arizonica
AZ: La Paz Co., , road to Salome
NW of I-10, Nov 2007


Chamaesyce celastroides
Kaua'i, Pu'u ka Pele Forest Reserve
 Sep 2003

Chamaesyce maculata
Bakersfield, CA
weed in garden

Chamaesyce parryi
El Paso Co., TX
Spjut 15027, Nov 2002

Chamaesyce micromera
CA: Imperial Co., CA. Spjut 16154A, Oct 2007.  Clay depressions in
creosote scrub, occurring as flat radial mats with another prostrate species, Ch. serpyllifolia.


Chamaesyce polycarpa

Left: Chuckwalla Mts., Sonoran Desert, CA Spjut & Marin 14577.  Right: E of 29 Palms, CA. Spjut 15267

Chamaesyce prostrata
Bakersfield, CA
weed in garden


Chamaesyce serpyllifolia
AZ: Maricopa Co. N of Ajo along 85
Nov 2007

Chamaesyce serpyllifolia
CA: Imperial Co., CA
Spjut 16154B, Oct 2007.
Abundant along road margins and in sandy creosote flats.




Yang, Y., R. Riina, J. J. Morawetz, T.  Haevermans, X. Aubriot and P. E. Berry. 2012. Molecular phylogenetics and classification of  Euphorbia subgenus Chamaesyce (Euphorbiaceae). Taxon: 61:764789. Euphorbia subg.Chamaesyce contains around 600 species and includes the largest New World radiation within theOld World-centered genus Euphorbia. It is one of the few plant lineages to include members with C3, C4 and CAM photosyn-thesis, showing multiple adaptations to warm and dry habitats. The subgenus includes North American-centered groups thatwere previously treated at various taxonomic ranks under the names of  Agaloma , Poinsettia , and Chamaesyce. Here we provide a well-resolved phylogeny of Euphorbia subg. Chamaesyce using nuclear ribosomal ITS and chloroplast ndhF sequences, with substantially increased taxon sampling compared to previous studies. Based on the phylogeny, we discuss theOld World origin of the subgenus, the evolution of cyathial morphology and growth forms, and then provide a formal sectionalclassification, with descriptions and species lists for each section or subsection we recognize.