Relative to other typical mushroom species , the spores of V. bohemica are huge , typically measuring 60 – 80 by 15 – 18 µm . They are elliptical , smooth , sometimes curved , and appear hyaline ( translucent ) to yellowish . The spores , which number two ( more rarely three ) per ascus are characteristic for this species . The smooth , elliptical asci measure 275 – 350 µm long by 16 – 23 µm wide . The British @-@ Canadian mycologist Arthur Henry Reginald Buller determined that the asci are heliotropic — they bend toward light . As he noted , " I cut transverse sections though their pilei , examined these sections under the microscope , and at once perceived that in all the hymenial grooves and depressions the asci was curved outwards so that their opercula must have faced the strongest rays of light to which the ends of the asci have been subjected in the places where the fruit @-@ bodies developed . " This response to the stimulus of light is significant because it permit a fruit body to point and later discharge its asci towards open spaces , thus increasing the chances that the spores will be dispersed by wind . The paraphyses are thick and club @-@ shaped , with diameters of 7 – 8 µm at their tips .