The pear can also be grown upon the apple, thorn and mountain ash. Upon the apple it is short-lived, although pear cions, set in the top of an old apple tree, often bear large fruits for a few years. When pear stocks cannot be had, pears are sometimes worked upon apple roots. If the cions are long they will emit roots, and when the apple nurse fails the pear becomes own-rooted. Good dwarf trees are often secured upon the thorn, and there is reason to believe that some of the thorns will be found to be preferable to quince stocks for severe climates and for special purposes. The subject is little understood. The mountain ash is sometimes used for the purpose of growing pears upon a sandy soil, but its use appears to be of little consequence. Pears of the Le Conte and Keiffer type are often grown from cuttings in the south. Cuttings are made of the recent mature growth, about a foot in length, and are planted in the open ground after the manner of long grape cuttings. Le Conte, Garber, Smith, and other very strong growers of the Chinese type, are probably best when grown from cuttings. They soon overgrow French stocks, as also apple stocks, which have been used to some extent; but if long cions are used, own-rooted trees are soon obtained, and the stock will have served a useful purpose in pushing the cion the first two or three years. =Pecan= (_Hicoria Pecan_). _Juglandeæ._ Propagated by seeds. These may be planted as soon as ripe, or stratified until spring. The ground should be well prepared and the nuts planted about 3 inches deep. By grafting on pecan or common hickory stock that is not over 2 years old. Cions about 6 inches long should be cut during the winter and put in a cool place to hold them back until the stocks have fairly started in the spring. The stalks should then be cut off at the crown and the cion inserted. The tongue-graft gives the best result. Bandage securely and bank with earth nearly to the top of the cion, to keep it moist. =Pelargonium= (Geranium, Stork's Bill). _Geraniaceæ._ Seeds, sown in light soil with mild heat, are sometimes employed. Commonly increased by cuttings of firm shoots, which grow readily (Figs. 52, _e_, and 55). The fancy or show geraniums are often grown from root-cuttings, but sometimes will not come true. Geraniums can also be grafted. (See page 39, herbaceous grafting.) =Pelecyphora= (Hatchet Cactus). _Cacteæ._ Propagated most freely by seeds in moderate heat, and by cuttings made of any small shoots that arise from the base See also Cactus. =Peliosanthes.= _Hæmodoraceæ._ Suckers. =Peltandra.= _Aroideæ._ Propagated by seeds when fresh, or by division. =Pennyroyal= (_Mentha Pulegium_). _Labiatæ._ Seeds and divisions. =Pentapetes.= _Sterculiaceæ._