| + | Perennial or annual herbs, tall and erect, or dwarf and more or less trailing: lvs. dentate or incised, the floral ones like the rest or reduced to bracts: whorls of fls. crowded in a dense spike, or in a loose cyme, rarely few-fld. and axillary; fls. blue or white, seldom yellow; calyx 15-nerved; corolla somewhat 2-lipped; upper lip straight or erect; lower lip spreading, 3-lobed, with the large center lobe concave; perfect stamens 4. in pairs, the 2 shorter ones in front; ovary 4-parted. The genus is placed near Lopanthus and Dracocephalum, and is characterized as follows: calyx tubular, the mouth straight or oblique, 5-toothed; stamens usually parallel, ascending; anther-cells divergent or divaricate.— About 150 species, mostly in the northern hemisphere outside the Old World tropics. |
| + | Catnip is a familiar weed near dwellings and barns. Cats are fond of it, and catnip tea is a pungent memory with those who have survived the era of homely simples. The seeds of catnip are still offered. Ground ivy (N. hederacea) also grows wild in America, and a form of it with variegated foliage is cultivated for edging flower-beds or covering banks and stones. It is hardy in light well-drained soils, but sometimes winter-kills in moist soils. It is also used in vases and baskets. N. hederacea is a perennial creeping plant of easy culture in any loose, rich, fairly moist soil in either shade or full sunlight, but to be luxuriant in the open it should have a moist rootage. It is a very rapid grower, and is therefore often troublesome when planted with other low-growing plants. It is very useful as a ground-covering in shrubbery borders and shady places generally, particularly where it can hang over curbs or edgings or where a good sward cannot be secured. |