Major dimensions of plant ecological strategies have been widely studied bringing forward the concept of 'economic spectra' of plants. Sexual reproductive traits, 'floral traits', have been largely neglected in this context, despite their strong link to fitness. Here, we aimed at integrating floral traits into the dimensionality of plant form and function so far dominated by vegetative traits. We used principal component analyses and constructed trait networks to assess the correlation structure of leaf, belowground, plant size-related, and floral traits. We studied forbs within two independent datasets; one compiled from central European trait databases and one sampled in the Austrian Alps. Floral traits defined the second dimension of trait variability within both datasets, while plant size determined the first dimension. Floral traits were largely independent from the leaf economic spectrum. Flower size, however, positively scaled with plant size and leaf size. Mating system was the most well-connected trait across modules of plant tissue/organ types. The independence of floral traits was consistent also after accounting for phylogenetic relationships between species. Floral traits explained a unique part of the variation in plant form and function and thus, likely play a distinctive ecological role within the whole plant economic spectrum.

CIDE UV CSIC 46113 Montcada Valencia Spain

Department of Botany Faculty of Science University of South Bohemia 37005 České Budějovice Czech Republic

Department of Environment and Biodiversity University of Salzburg 5020 Salzburg Austria

Evolutionary Ecology of Plants Department of Biology University of Marburg 35043 Marburg Germany

Institute of Botany of the Czech Academy of Sciences 37982 Třeboň Czech Republic

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