P. TRILOBA (syns P. virgata, Amygdalopsis Lindleyi and Prunopsis Lindleyi).—­China, 1857.  This is a very handsome early-flowering shrub, that is at once recognised by the generally three-lobed leaves.  It is one of the first to flower, the blossoms being produced in March and April, and sometimes even earlier when the plant is grown against a sunny, sheltered wall.  The semi-double flowers are large and of good substance, and of a rosy-white tint, but deep rose in the bud state.  There is a nursery form of this plant with white flowers, named P. triloba alba.  It is quite hardy, bears pruning well, and grows quickly, soon covering a large space of a wall or warm, sunny bank.  As an ornamental flowering lawn shrub it has few equals, the blossoms remaining good for fully a fortnight.

P. VIRGINIANA (syn Cerasus virginiana) and P. SEROTINA (North American Bird Cherries) are worthy species, with long clusters of flowers resembling those of our native Bird Cherry.  They are large-growing species, and, particularly the latter, are finding favour with cultivators in this country on account of their bold and ornamental appearance.

PTELEA.

PTELEA TRIFOLIATA.—­Hop Tree, or Swamp Dogwood.  North America, 1704.  A small-growing tree, with trifoliolate, yellowish-green leaves placed on long footstalks, and inconspicuous greenish flowers.  The leaves, when bruised, emit an odour resembling Hops.  P. trifoliata variegata is one of the handsomest of golden-leaved trees, and is well worthy of extensive planting.  It is preferable in leaf colouring to the golden Elder.  Perfectly hardy.

PUNICA.

PUNICA GRANATUM.—­Pomegranate.  For planting against a southern-facing wall this pretty shrub is well suited, but it is not sufficiently hardy for the colder parts of the country.  Frequently in the more favoured parts of the country it reaches a height of 14 feet, with a branch-spread of nearly as much, and is then, when in full flower, an object of general admiration and of the greatest beauty.  The flowers are of a rich, bright scarlet colour, and well set off by the glossy, dark green leaves.  P. Granatum rubra flore-pleno is a decidedly ornamental shrub, in which the flowers are of a bright scarlet, and perfectly double.  They grow satisfactorily in light, but rich soil.

PYRUS.

PYRUS ARIA.—­White Beam Tree.  Europe (Britain).  A shrub or small-growing tree, with lobed leaves, covered thickly on the under sides with a close, flocculent down.  The flowers are small and white, and produced in loose corymbs.  It is a handsome small tree, especially when the leaves are ruffled by the wind and the under sides revealed to view.  The red or scarlet fruit is showy and beautiful.

P. AUCUPARIA.—­Mountain Ash, or Rowan Tree.  Too well-known to need description, but one of our handsomest small-growing trees, and whether for the sake of its dense corymbs of small white flowers or large bunches of scarlet fruit it is always welcomed and admired.  P. Aucuparia pendula has the branches inclined to be pendulous; and P. Aucuparia fructo-luteo differs from the normal plant in having yellowish instead of scarlet fruit.