Abstract Detail

Floristics & Taxonomy

Koenemann, Daniel Mark [1].

An Analysis of the Triplaris americana Species Complex.

Triplaris Loefl. ex L. (Polygonaceae) is a genus of fast-growing dioecious trees native to the Neotropics. The genus is currently circumscribed to contain 18 species, many of which are colonizers common in disturbed sites and at forest edges. Prior to the most recent taxonomic revision of the genus, there were nearly 90 names associated with Triplaris. Many of these names were either excluded or placed in synonymy by that revision. One species in particular, Triplaris americana, had an additional 15 taxa, including one species of Ruprechtia (the sister genus), placed in synonymy with it. Additionally, plants currently classified as Triplaris americana are found throughout the Neotropics, inhabit numerous different environments, and manifest notable morphological heterogeneity. To determine if the current circumscription of Triplaris americana is appropriate, I conducted a morphometric study of 136 herbarium specimens, using 51 characters, both quantitative and qualitative. I analyzed these data as a mixed dataset by converting the raw data into a Gower distance matrix and then using hierarchical clustering to identify groups within Triplaris americana. The clustering analysis revealed that specimens currently classified as Triplaris americana could be subdivided into two, three, or four groups. Of these, the best explanation was that plants currently classified as Triplaris americana be understood as two groups of things, rather than one. Plants in the first group are distributed primarily in the Várzea and riparian forests of Venezuela, Colombia, Peru, and Amazonian Brazil, and have shorter, wider, and hairier leaves. I propose retaining the name Triplaris americana for this entity. Plants in the second group are distributed primarily in the dry forests, scrub forests, and fields of Bolivia and the Brazilian Cerrado, and have longer, narrower, and usually glabrous leaves. I propose re-recognizing the name Triplaris estriata for this entity.

1 - Howard University, Biology Department

Keywords:
Neotropics
Hierarchical  clustering
Morphometrics
Polygonaceae.

Presentation Type: Oral Paper
Session: FTI, Floristics & Taxonomy I
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 10:00 AM(EDT)
Number: FTI001
Abstract ID:78
Candidate for Awards:None