Foxglove beard-tongue, Penstemon digitalis Family: Plantaginaceae Pollen grain morphology: tricolporate, spheroidal, psilate Pollen grain size: 32.28 ± 0.40 µm by 30.63 ± 1.16 µm May 1, 2015plantaginaceae, Uncategorizeddigitalis, foxglove, foxglove beard-tongue, penstemon, psilate, spheroidal, tricolporate