Botany & Type Specimens: the peculiar case of THOPOR

Botany is a science grounded in historical events.  Sometimes, this history is a mystery and can tell us something about the intrigue of a given species. 
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​Below the description of Thouinia striata var. portoricensis (THOPOR) from Wadsworth and Woodbury: Trees of Puerto Rico and and the Virgin Islands Vol.1 (published in 1964):  

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From the description, one can understand (among other things) that THOPOR is an endemic tree found in the Southwest of Puerto Rico, belongs to the Sapindaceae family, and that there are various identifying characteristics of the species (e.g., leathery, elliptical leaves, sometimes in threes with a toothed margin; etc.)

In my opinion, what is astounding and continually fascinates me is how we to got this place (botanically).  The Wadsworth and Woodbury is one of many books that documents the world's flora.  In this case, arguably thousands of botanists (perhaps millions) must have looked at this species, contemplated its synapomorphy (i.e., the shared unique characteristics that separate this species and its relatives from other plants), and conjectured about its evolution. 

Furthermore, and perhaps more remarkable, is how well these botanists did at describing evolutionary relationships of rare species like THOPOR, purely based on morphological characteristics (i.e., pure cladistics).  Modern DNA analyses continually reveal small subtleties in the angiosperm phylogeny, but the botanists of the eighteenth and nineteenth centuries got improbably close, simply using morphologies.

That is where type specimens come in.  The naturalist (botanist, mycologist, etc.) who first discovers and collects a species that is new to science is entrusted with the description of that species.  Each description must refer to a collection (i.e., an herbarium specimen), and usually the first registered collection of any new plant species is deemed the type (or holotype) specimen, and is forever the gold standard for comparison and determination of all other collections of that species.  

But what happens if there are two collected specimens?  Well, then they each become syntypes.  In this particular case, on the 3rd of May 1886 in the Bosque Seco of Guanica, Paul Ernst Emil Sintenis collected two specimens of THOPOR, which turned out to be a new species at the time. He probably did this because of the variable leaf morphology of the species, which sometimes is trifoliate but not always.  Therefore, two syntypes exist. 

Below are both syntype specimens for Thouinia striata var. portoricensis ​ (both of which can be found in the collections of the Missouri Botanical Garden):  

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I leave you with several botanical images of the species.  Photos by Ricardo Rivera.♠