X-ray phase-contrast (XPC) imaging methods are well-suited for lung imaging applications due To The weakly absorbing nature of lung Tissue and The strong refractive effects associated with Tissue-Air interfaces. Until recently, XPC lung imaging had only been accomplished at synchrotron facilities. In This work, we investigate The manifestation of speckle in propagation-based XPC images of mouse lungs acquired in situ by use of a benchtop imager. The key contributions of The work are: a) The demonstration That lung speckle can be observed by use of a benchtop XPC imaging system employing a polychromatic Tube-source; and b) a systematic experimental investigation of how The Texture of The speckle pattern depends on The parameters of The imaging system. Our analyses consists of image Texture characterization based on The statistical properties of pixel intensity distributions. Results show how image Texture measures of lung regions are strongly dependent on imaging system parameters associated with XPC sensitivity.