Idioblasts and other unusual internal foliar secretory structures in Scrophulariaceae

Leaf samples of mostly herbarium specimens (237 species of 172 general were cleared. Internal secretory structures of large size or unusual shape were detected and observed. Selected samples were processed into resin and sect ioned for light microscopy or prepared for scanning electron microscopy. Ad ding results from two earlier publications, our survey includes 365 species from 174 genera. Five types of internal secretory structure, mostly unknow n previously in the traditional Scrophulariaceae, occur in only nine genera : 1) single-celled subepidermal idioblasts, empty at maturity, in Scrophula ria and Verbascum (Lersten and Curtis 1997), 2) 2-16 (or morel-celled nodul es, with fibrous contents, in mid-mesophyll strata of Graderia and Radamaea 3) epithelium-lined oil cavities in Leucophyllum (Lersten and Beaman 1998) and Capraria, 4) Kranz-type enlarged bundle sheath in Anticharis, and 5) p araveinal mesophyll (PVM) in Picria and Bonnaya.