Fig. 3.

Glandular hairs of three species stained with phosphatase substrate under epifluorescence and normal light microscopy (Upper vs. Lower, respectively, labeled EFM vs. LM, respectively). Yellow-green fluorescence indicates substrate hydrolysis for glandular hair from leaf of carnivorous Drosera rotundifolia and glandular hairs from the upper scape of putatively carnivorous Triantha occidentalis; glandular hairs on the stem of the noncarnivore Geranium robertianum exhibit slight blue autofluorescence but no apparent yellow-green fluorescence. (Scale bars: 2 mm.)