Pittósporums, about nine species, with handsome foliage, and small white flowers in clusters, which are fragrant. P. Tobìra is a native of China, and nearly hardy; leaves lucid, obovate, obtuse, and smooth. P. undulàtum, P. coriàceum, P. revolùtum, P. fúlvum, and P. ferrugíneum, are very ornamental evergreens, and will grow with the most simple treatment.
Platylòbiums, Flat Pea, four species of fine free flowering plants; flowers leguminose; colour yellow. P. formòsum, P. oràtum, and P. triangulàre, are the best; the foliage of the two former is cordate, ovate; the latter hastate, with spiny angles.
Pistàcias, seven species of trees, principally of the south of Europe. There is nothing particular in their appearance, except their productions in their native country. P. terebínthus is deciduous, and produces the Cyprus turpentine. P. lentíscus is the true mastich tree, which is obtained by cutting transverse incisions in the bark. P. vèra and P. reticulàta are good species; leaves pinnated; leaflets ovate, lanceolate; easily cultivated.
Plumbàgos, Lead-wort. There are only two species of any consequence belonging to the Green-house, P. trístis and P. capénsis. The former is a shy flowerer, but the latter flowers freely; colour beautiful light blue, and flowers in spikes; foliage oblong, entire, and a little glaucous; of very easy culture, and continues in bloom a considerable time.
Psoràleas, above forty species. A few of them are worthy of cultivation, P. odoratíssima, P. spicàta, P. aculeàta, P. argéntea, and P. tomentòsa. They have all blue flowers, and leguminose. They are chiefly low shrubs; and will flower and grow freely; the pots require draining.
Podalyrias, about fourteen species of pretty Cape shrubs; foliage oblong, obovate, and silky-like; the flowers leguminose; colour blue or pink. P. serícea, P. styracifòlia, P. corúscans, P. argéntea, P. liparioídes, and P. subbiflòra, are the finest and most distinct species, and flower abundantly.
Petsoónias, about sixteen species of dwarf evergreen shrubs; leaves oblong, or lanceolate, hairy, or downy; flowers axillary and solitary; the pots should be well drained, and the plants in summer protected from the sun. P. hirsùta, P. móllis, P. teretifòlia, and P. lùcida, are the most distinct, and grow freely.
Pròteas, about forty-four species. The foliage of this genus is very diversified; flowers very large, terminale; stamens protected by an involucrum; many-leaved and imbricated; which is very persistent. P. cynaroídes has the largest flower, which is purple, green, and red. P. speciòsa, P. umbonàlis, once P. longifòlia, P. melaleùca, P. grandiflòra, P. coccínea, P. cenocárpa, P. pállens, P. formòsa, P. magnífica, P. speciòsa rúbra, and P. mellífera, will afford a very good variety. It is almost impossible to describe their true colour, it being so various; red, white, straw, brown, green, and purple, are most predominant, and frequently to be seen in the same flower; the plants must be well drained; and during warm weather be careful that they are not neglected in water, for if they are suffered to droop, they seldom recover. For this reason the pots ought not to stand in the strong sun; the plants can bear it, but to the roots it is injurious.
Pultenæas, about forty species, pretty little dwarf growing shrubs of New South Wales; flowers small, leguminose, all yellow, with a little red outside of the petals. P. villòsa, P. obcordàta, P. argéntea, P. plumòsa, P. fléxilis, shining leaved, fragrant; P. cándida, and P. strìcta, are all fine species, and esteemed in collections. The leaves are all small; they require an airy exposure, and the pots drained.