Photo: Claudia Lipke

Natalia Ivalú Cacho

Department of Botany

430 Lincoln Drive

University of Wisconsin

Madison, WI 53706-1381

Office: 342 Birge Hall
Phone: (608) -890-1515

Fax: (608) 262-7509
Email: nicacho@wisc.edu

Educational Background:

BS in Biology, UNAM (Universidad Nacional Autónoma de México), 2003

Research Interests:

Diversity of life forms, evolution (patterns and processes), systematics and floral evolution of Euphorbiaceae, tropical dry forests

Hobbies:

Reading, hiking, biking, music, movies, traveling, PERL, dancing (and OK, under special circumstances I knit!)

E. calcarata habit

Current Projects:

E. coalcomanensis habitat

Phylogeny of the slipper-spurges (Pedilanthus clade, Euphorbia, Euphorbiaceae)

Project Summary:

This neotropical clade nested within Euphorbia is characterized by its spurred zygomorphic cyathium. All fifteen species of the clade may be found in Mexico, and twelve of them are endemic to the seasonally dry tropical forests of this country. The Pedilanthus clade is unique in the high life-form diversity it exhibits in so small a group: from desert succulents all the way to evergreen treelets of tropical wet forests. Associated with this habit diversity, stems, roots and leaves vary in form and anatomy. The diversity exhibited by the Pedilanthus clade is not restricted to its vegetative morphology, but is observed in its cyathium morphology and its pollination agents, which range from hummingbirds to insects, presumably hymenopterans. Are the variations observed in the clade examples of convergence or are they shared among sister taxa or subclades? The diversity that the clade shows at various levels, its manageable size and its well supported monophyly make it an excellent candidate to test evolutionary hypotheses. I am currently completing the reconstruction of a phylogeny of the group to provide the framework needed to make evolutionary-hypothesis testing possible.

Cyathia     

E. calcarata	E. peritropoides	E. personata	E. diazlunana

E. peritropoides habit

E. tithymaloides habit

E. finkii habit

E. tehuacana habit

E. tithymaloides ssp. padifolia cyathium

Phylogeography of Euphorbia tithymaloides

(Pedilanthus clade)

Project Summary:

This is the most widespread species of the Pedilanthus clade (see above). Its distribution ranges from northeastern Mexico and Florida to northern South America, throughout Central America and the Caribbean. Furthermore, this is the only species of the clade for which subspecific differentiation has been proposed, with eight subspecies described so far. I am interested in looking at how this species colonized the Caribbean Basin, if via one, two, or multiple colonization fronts, and to explore biogeographical patterns in its distribution.

Fieldwork:

The Pedilanthus clade projects involve collecting in Mexico, US, Central and South America, and the Caribbean. So far, these are some of the places I have been to hunting for slipper-spurges:

Mexico, Virgin Islands (US), Guatemala, Venezuela, Costa Rica, Dominican Republic                          Lesser Antilles, Jamaica, Florida, and Puerto Rico

E. tithymaloides ssp. tithymaloides habitat

Evolution of the cyathium (Euphorbia, Euphorbieae)

Project Summary:

The questions are big: Why, how and when the cyathium evolved? What are the implications of the cyathium evolution in terms of pollination shifts and diversification in Euphorbia? What are the mechanisms underlying the formation of this beautifully complex structure?

My current focus is on gene expression patterns on some key taxa across Malpighiales, focusing on Euphorbiaceae, specifically the giant genus Euphorbia. This project is being carried out in collaboration with Gerhard Prenner and Paula Rudall (http://www.uni-graz.at/~prennerg/home.htm). I know, sounds like lots of work, and it is. It also sounds like lots of fun, and it is!

E. conzattii cyathium

E. conzattii habit

E. diazlunana habit

E. conzattii is restricted to this mountain's top!