Data from: The distinction between herbaceous and woody Piperales species by trait syndromes of leaf hydraulics and gas exchange.

<b></b>Basal angiosperms are mostly woody species, while Chloranthales and Piperales consist of a certain number of herbaceous species. However, it remains unknown whether leaf hydraulic traits would differ between woody and herbaceous basal angiosperms. In this study, we measured 11 leaf traits that are related to leaf hydraulics and photosynthesis in 11 Piperales species. The leaf vein density and photosynthetic rate of these species were at the low ranges of angiosperms because of leaf hydraulic constraint of the former. No significant difference was found in leaf hydraulic conductance and photosynthetic rate, but the results indicated that woody species possessed more negative turgor loss point and higher leaf density. Although there is no significant correlation between leaf photosynthesis rate and leaf hydraulic conductance, leaf photosynthetic rate was indirectly linked to leaf hydraulic conductance via stomatal conductance but directly to turgor loss point. Our results suggested that woody species tended to have higher leaf investment and higher drought tolerance while herbaceous species tends to have lower investments and lower drought tolerance. We also suggested that the photosynthetic rate was enhanced by increasing stomatal conductance from leaf hydraulic conductance in Piperales. Our study provides a new understanding of the hydraulic evolution and its effect to photosynthesis in basal angiosperms.<br>