THE DICTIONARY OF GARDENING, 



PLOCOGLOTTIS (from plokos, a fold, and glotta, a 

 tongue ; referring to a fold in the lip). OED. Orchidew. 

 A genus comprising eight species of stove, terrestrial 

 orchids, with the habit of Eulophia, natives of the 

 Malayan Archipelago. Flowers mediocre, shortly pedi- 

 cellate, racemose ; sepals connate beneath the lip, larger 

 than the petals, which are curved at the apex ; lip con- 

 nate with the column on either side by inflexed, mem- 

 branous folds, its limb being convex, undivided, patent, 

 at first erect; column free above; anthers two-celled; 

 pollinia four, round, with two long, replicate caudicles ; 

 peduncles or scapes leafless. Leaves ample, membranous, 

 plicate. Stem or rhizomes creeping, one or many-leaved, 

 not distinctly pseudo-bulbous at base. For culture of 

 P. Lowii, the only species introduced, see Cyrto- 

 podram. 



P. Lowii (Low's), fl. ochre-coloured, spotted with brown, borne 

 in a spike on a long, hairy scape. I. cuneate-oblong. Pseudo- 

 bulbs obpyriform. Borneo, 1865. (R. X. O. 154.) 



PLOCOSTEMMA. Included under Hoya. 

 PLCESSLIA. A synonym of Boswellia. 

 PLOUGHMAN'S SPIKENARD. See Baccharis. 



PLUCHEA (so called after N. A. Pluche, who pub- 

 lished the " Spectacle de la Nature," at Paris, in 1732). 

 Marsh Fleabane. STNS. Conyza (in part), Gymnema (of 

 Rafinesque), Leptogyne, Stylimnus. Including Karelinia. 

 OBD. Composites. A genus comprising nearly thirty 

 species of greenhouse, tomentose, villous, or sometimes 

 glutinous shrubs or sub-shrubs, rarely hardy perennial 

 herbs, natives of the warmer regions of America, Africa, 

 Asia, and Australia. Flower-heads white, yellow, or lilac, 

 heterogamous, in the typical species small, disposed in 

 corymbose, leafless, terminal cymes ; in a few species, 

 larger and solitary at the apices of the branches, or 

 rather large and crowded at the tips of leafless 

 branches; involucre ovoid, broadly campanulate or sub- 

 hemispherical, the bracts few or many-seriate ; receptacle 

 flat, naked ; achenes glabrous or pilose. Leaves alter- 

 nate, toothed, or rarely entire or pinnatifid. Few of the 

 species are of any horticultural value. P. caspica is of 

 very easy culture in the open border, and may be pro- 

 pagated by seeds, or by divisions. 



P. caspica (Caspian), fl. -heads purple, cylindrical, terminal, 

 corymbose. August. I. oblong, lanceolate, entire, h. 2ft. to 3ft. 

 Borders of Caspian Sea and Siberia. Hardy, herbaceous 

 perennial. SYN. Karelinia cuspid. 



PLUM. The origin of many of our cultivated Plums 

 is quite unknown ; several of them, no doubt, have sprung 

 from Primus domestica, but, in all probability, other wild 

 types have contributed. According to some authorities, 

 the Sloe, or Blackthorn (P. spinosa), the Bullace (P. 

 insititia), and the Wild Plum (P. domestica) are merely 

 sub-species, and are united into one species under the 

 name of P. communis, which is found in a wild state 

 throughout Europe and West Africa. " The Sloe is con- 

 fined to Europe, the Bullace extends to North Africa and 

 the Himalaya" (Hooker). The Plum is a deciduous tree, 

 attaining a height of from 15ft. to 20ft., and forming 

 a moderately spreading head. From the amount of in- 

 formation which is at command regarding Plums, it would 

 seem that various sorts were introduced into this country 

 from France and Italy during the fifteenth century. The 

 fruit has, therefore, been grown from a remote period, and 

 the date when its cultivation first began is very uncertain. 

 Plums are the hardiest of stone-fruits, and the crop is 

 one of the most remunerative, in all favourable seasons, 

 from market gardens and cultivated orchards. In private 

 establishments, the fruits of all the best varieties are 

 much valued for dessert, and those of the coarser and 

 less highly- flavoured ones prove invaluable for cooking 

 and preserving. For the latter purpose, hundreds of tons 

 of the fruit are, in a favourable season, sent from the 

 surrounding market gardens to London alone. The crop 



Plum continued. 



is therefore one of the most important, both for market 

 and for private consumption. A fruiting branch is re- 

 presented at Fig. 204. 



Propagation. Budding and grafting are the chief 

 methods by which varieties of Plums are propagated. 

 Young trees may also be readily raised from seeds, and 

 from suckers. Suckers are only occasionally used, and 

 should never be employed as stocks. The Plum is 

 naturally inclined to spread its roots, and throw up 

 numerous suckers; and, if these are replanted, or used 

 as stocks, the tendency to be constantly throwing up 

 other shoots from the base is afterwards apparent. Some 

 sorts reproduce themselves nearly true from seeds, as, 

 for instance, the Green Gage ; but seedlings generally 

 vary more or less from the original, and it is, therefore, 

 best not to depend on this mode of propagation beyond 

 the raising of seedlings as stocks, except, perhaps, with 

 Damsons, which may be raised from the stones. Plum 

 stocks are required in large numbers for Peaches, Nec- 

 tarines, and Apricots, as well as for Plums. The seeds 



FIG. 204. FRUITING BRANCH OF PLUM. 



may be sown when taken from the fruit ; or they may 

 be stratified, and sown in autumn or early spring. In 

 the autumn following, the stocks will be ready for trans- 

 planting into nursery lines, preparatory to budding or 

 grafting when large enough. For Plum stocks, the 

 varieties best suited are the Damson, Mussel, St. 

 Julien, and White Pear. The Mussel answers well as 

 a stock for standard trees. Shield-budding in July 

 and August, and ordinary cleft-grafting in March, 

 or just before the sap ceases to flow in September, are the 

 most successful methods to adopt. In budding, it is most 

 important that wood, and not blossom, buds be inserted ; 

 and, in grafting, wood-buds, which are sometimes very 

 scarce on scions, must be carefully preserved. Stocks for 

 grafting must be prepared by being headed-down early 

 in the year, before growth begins ; and the scions should 

 be cut at the same time, or even earlier, and laid with 

 their ends in the ground. Attention must specially be 

 given to this particular, or a successful union of the parts 

 at grafting-time will be out of the question. Standard 

 Plums may be worked near the ground, and the scion 

 allowed to make its own stem, or at the proper height, 



