Disentangling the Taxonomic Variations within the High-Andean Complex Gomphrena meyeniana (Gomphrenoideae, Amaranthaceae)

BENA, MARÍA JULIA; ORTUÑO, TERESA; ACOSTA, JUAN MANUEL

SYSTEMATIC BOTANY

AMER SOC PLANT TAXONOMISTS

Lugar: Laramie; Año: 2020 vol. 45 p. 294 - 305

0363-6445

Gomphrenameyeniana isan extremely variable species from the Andean highlands, which hasattracted the attention of many botanists because it is the world?shighest-elevation C4eudicot and because of its wide morphological variability. It has thetypical high-Andean plant morphology, with small leaves tightlyclustered on a thick rootstock. The large range of morphologicalvariation within this species coupled with the varying opinions onthe existence of several species or infra-specific taxa and the lackof molecular information has made the clarification of the G.meyenianacomplex a challenge. Our approach was to perform broad molecularsampling to identify the phylogenetic position of G.meyeniana withinGomphrenaand to perform a multivariate analysis to objectively differentiatetaxa based on morphological characters. TheITS and trnL-Fregions were analyzed individually and combined using Bayesianinference and maximum parsimony methods. To analyze the morphologicalcharacters we performed a clustering method (partitioning aroundmedoids with the Gower?s dissimilarity algorithm).Themolecular analyses supported the monophyly of the G.meyeniana complex,but didnot support segregation into varieties.The morphological analyses supported recognition of three varietiesthat can be easily distinguished by three simple characters: thepresence of leaves on the flowering shoot, the habit of the floweringshoot, and the pilosity of the tepals. The varieties of G.meyenianaaccepted here are var. meyeniana,var. caulescens,and var. flaccida.A dichotomous key to identify the infra-specific taxa is herepresented and illustrated. The varieties tucumanensisand conwayiare synonymized with var. caulescensand var. meyeniana,respectively.p { margin-bottom: 0.1in; direction: ltr; color: rgb(0, 0, 10); line-height: 120%; text-align: left; }p.western { font-family: "Calibri", serif; font-size: 11pt; }p.cjk { font-family: "Calibri"; font-size: 11pt; }p.ctl { font-size: 11pt; }a:link { color: rgb(0, 0, 255); }