 The stem is 4 – 10 cm ( 1 @.@ 6 – 3 @.@ 9 in ) long by 1 – 2 @.@ 5 cm ( 0 @.@ 4 – 1 @.@ 0 in ) thick , and is either roughly equal in width throughout its length , or has a basal or middle swelling . The stem tissue is hard and brittle ; it is initially stuffed with a soft pith that develops cavities , or becomes entirely hollow in maturity . Roughly the same color as the cap or lighter , the stem surface is dry and lacks reticulations . It is initially covered in coarse hairs that tend to disappear in maturity to leave a relatively smooth surface . All parts of the fruit body stain blue when cut or injured . The variety G. cyanescens var. violaceotinctus is nearly identical in appearance , but stains dark lilac to indigo when bruised . The odor and taste of the fruit bodies is indistinct . 
