Pampas Grass.—­See “Gynerium.”

Pampas Lily of the Valley.—­See “Withania.”

Pancratium.—­A handsome class of plants.  Their habit of growth is somewhat like that of the Amaryllis.  They are admirably adapted for growing in pots in the greenhouse.  They may also be planted in the open ground under a south wall.  The bulbs should be placed in a composition of three parts light, sandy loam and one of vegetable mould.  They are increased by off-sets from the roots, or by seeds, by which the new varieties are obtained.  Height, 1 ft. to 2 ft.

Pandanus Veitchi (Variegated Screw Pine).—­For table decoration or vases this is a most useful plant.  It requires a warm greenhouse where a temperature of 60 or 70 degrees can be kept up throughout the year, and grows well in equal parts of peat and loam with one-sixth part sand.  During the autumn a little liquid manure is beneficial.  In the winter months it should be watered carefully, but in the summer it is improved by syringing with warm water.  It is propagated very easily by suckers taken off in spring or summer, placed in a temperature of 75 degrees.

Panicum.—­Handsome ornamental grasses.  They will grow in any soil or situation.  P. Capillare is an annual, suitable for bouquets or edgings; it is increased by seed.  P. Altissimum, an annual, and P. Sulcatum, a most elegant greenhouse plant, are fine for specimens.  P. Plicatum is highly ornamental and hardy, but is best grown as a conservatory or window plant; it has a Palm-like appearance, and is of quick growth.  Most of the plants flower in July.  They may be propagated by seed or by division of the roots.  Average height, 1-1/2 ft.

Pansies (Heartsease).—­Grow well from seed sown in July or August on a raised bed of light earth.  They may also be increased from cuttings taken in August, September, April, or May, selecting young side-shoots and planting them in light earth mixed with silver sand.  The cuttings should be kept in a cool frame, moderately moist, and shaded from the hot sun.  They can likewise be increased by layers, merely pegging them down and not slitting them on account of their tendency to damp off.  They may also be increased by dividing the roots in April or May.  They should be planted where they will get all the morning sun, yet be sheltered from mid-day rays; in an open and airy situation, yet protected from cutting winds.  While the plants are blooming they should be supplied with liquid manure.

Papaver (Poppy).—­These showy flowers are most at home in a rich, light soil.  They are easily raised from seed sown where they are intended to bloom.  The perennials may also be increased by dividing the roots.  They flower at midsummer.  Height varies from 1 ft. to 3 ft.

Pardanthus Chinensis.—­See “Iris.”