478 THE POLEMONIALES 



sect with the greatest precision to particular parts of the flower 

 with a view to crossing, mark this family of the mints as the 

 most speciaUzed of the order. A fine series of devices are seen 

 in such common mints as the blue curls {Tricho sterna) , skull- 

 cap {Scutellaria), hyssop (Agastache), ground ivy (Glecoma), 

 catmint (Nepeta), selfheal (Prunella), motherwort (Leonurus), 

 dead nettle (Lamium), hedge nettle (Stachys), sage (Salvia), 

 bergamot (Monarda), pennyroyal (Hedeoma), mountain mint 

 (Kolleia), bugle weed (Lycopiis), etc. Many of these plants 

 are of commercial importance. Mentha yields valuable oils as 

 spearmint, peppermint, and menthol and from other genera are 

 derived oils used in perfumery, medicine and as condiments, 

 as rosemary, lavender, origanum, thyme. Several are cultivated 

 for their flowers and foliage, as the coleus, monarda, stachys, etc. 

 The large family of figworts, Scrophulariaceae, with its 2,400 

 species, closely resembles the mints, but is distinguished by the 

 ovary being undivided and containing many seeds on a central 

 axis (Fig. 333, C). While the simpler forms have almost regular 

 corollas and five stamens, the higher forms are bilabiate with 

 two to four stamens as in the mints. This family contains some 

 of the most showy of our cultivated plants, as the foxglove 

 (Dasystoma and Digitalis), Gerardia, snapdragon (Antirrhi- 

 num), rattlebox (Rhinanthus) , toadflax (Linaria), Paulownia, 

 beardtongue (Pentstemon) , monkey flower (Mimulus) ; and the 

 allied Catalpa and trumpet creeper; also many other attractive 

 plants that are not cultivated as the mullen ( Verbascum) , fig- 

 wort (Scrophularia) , turtle head (Chelone), hedge hyssop (Gra- 

 tiola), speedwell (Veronica), painted cup (Castilleja) , lousewort 

 (Pedicularis), cow-wheat (Melampyrum). These plants are 

 among the most characteristic features of our flora, the family 

 being largely confined in its distribution to the north temperate 

 regions. The flower of the toadflax (Linaria) illustrates a com- 

 mon type of the figwort family (Fig. 333). Such flowers are 

 said to be personate, that is bilabiate but with the under lip 

 arched so as to meet the upper lip and entirely closing the mouth 

 of the corolla. This arrangement very effectively protects the 

 microspores and conceals the nectar and it requires a rather 



