N. THYRSIFLORA, Nepaul, 1850, would seem to be quite as hardy as N. opulifolia, and is of more evergreen habit.  The leaves are doubly serrated and three lobed, and cordate-ovate.  Flowers white in spicate, thyrsoid racemes, and produced rather sparsely.

NESAEA.

NESAEA SALICIFOLIA (syn Heimia salicifolia).—­Mexico, 1821.  This can only be styled as half hardy, but with wall protection it forms a pretty bush often fully a yard in height.  The leaves resemble those of some species of Willow, being long and narrow, while the showy yellow flowers are freely produced in August and September.  It thrives best when planted in light, dry soil, and in a sheltered position.

NEVIUSA.

NEVIUSA ALABAMENSIS.—­Alabama Snow Wreath.  Alabama, 1879.  This is a rare American shrub, with leaves reminding one of those of the Nine Bark, Neillia opulifolia, and the flowers, which are freely produced along the full length of the shoots, are white or yellowish-green, with prominent stamens of a tufted brush-like character.  It is usually treated as a green-house plant, but may be seen growing and flowering freely in the open ground at Kew.

NUTTALLIA.

NUTTALLIA CERASIFORMIS.—­Osoberry.  California, 1848.  This shrub is of great value on account of the flowers being produced in the early weeks of the year, and when flowers are few and far between.  It grows from 6 feet to 10 feet high, with a thick, twiggy head, and drooping racemes of white flowers borne thickly all over the plant.  Few soils come amiss to this neglected shrub, it growing and flowering freely even on poor gravelly clay, and where only a limited number of shrubs could succeed.

OLEARIA.

OLEARIA HAASTII.—­New Zealand, 1872.  This Composite shrub is only hardy in the milder parts of England and Ireland.  It is of stiff, dwarf growth, rarely growing more than 4 feet high, but of neat and compact habit.  Flowering as it does in late summer it is rendered of special value, the Daisy-like white blossoms being produced in large and flat clusters at the branch tips.  The leaves are neat and of leathery texture, and being evergreen lend an additional charm to the shrub.

O. MACRODONTA (syn O. dentata), from New Zealand, 1886, is tolerably hardy, and may be seen in good form both at Kew and in the South of Ireland.  The large Holly-like leaves are of a peculiar silvery-green tint above, and almost white on the under sides.  Flowers white, and produced in dense heads in June and July.

O. Forsterii and O. Gunniana (syn Eurybia Gunniana) are nearly hardy species, the latter, from New Zealand, bearing a profusion of white Daisy-like flowers on dense, twiggy branches.

ONONIS.