88 



Garden and Forest. 



[February 20, 1889. 



pusilla), and the pine linnet {Chrysomitris pinus), and the thistle 

 bird (C tristis), eating seeds from plants growing on the road- 

 sides and in fields. 



Passing on through these open barrens, we soon reach a 

 dense Cedar-swamp, which for several seasons past I have 

 promised myself I would explore in the winter. Along its 

 borders we find the rare local Helo7iias bullata growing in large 

 clumps, with leaves fresh and bright, somewhat resembling 

 those of the old-fashioned White Lily (Liliiim candidmn); but 

 the leaves are more shining and larger, and withstand the 

 frost better than the Lily. And very beautiful they are here in 

 mid-winter, standing up in great rosettes, and looking more 

 appropriately placed and beautiful than they ever do in a 

 garden. 



What I saw within the gloom of the Cedars must be told in 

 another letter. 



Vineland, January, 1889. Marj Treat. 



History of the White Lilac Industry. 



FOR a long time it was generally, and even now is by many, 

 believed, that to obtain White Lilac flowers during winter, 

 the plants should be forced in a dark place. Such, however, 

 is not an absolute necessity by any means ; it is practically 

 a question of heat, and, given this. White Lilacs can be easily 

 produced in fully-lighted houses. The varieties mostly grown 

 for this purpose are Charles X. and Rouge de Marly, both of 

 which are cultivated in enormous quantities in France, and 

 also in England, for forcing. Formerly Covent Garden was 

 supplied almost exclusively from France, but now many 

 English establishments are devoted to this special branch of 

 the flower-trade. In some of these a system prevails by means 

 of which the bushes to be forced are retarded to such an 

 extent that the flower-market is furnished with fine White 

 Lilacs (forced) long after unforced bushes in the open air have 

 ceased flowering. The exact means adopted to secure these 

 results are not divulged by those who practice them ; the 

 rough-and-ready plan of stripping off all the leaves of estab- 

 lished plants in the open air, and so causing a second growth 

 and a crop of flowers in autumn, is, however, not the one 

 adopted by the Covent Garden growers. The white-flowered 

 forms are not used for early forcing, they are not sufficiently 

 vigorous, and the two red-flowered ones above-mentioned are 

 almost invariably used. The red coloring matter, however, 

 exists in such a quantity in some — for instance, Andenken and 

 Ludwig Spath, a handsome dark-colored form of recent 

 origin — that, even in the dark, white flowers cannot be 

 produced. 



In connection with this subject, the historical notes of M. 

 Hiring, in a recent volume of the Jourttal de Botanique, are 

 of especial interest. As early as 1820 we learn that several 

 French gardeners had tried the forcing and bleaching process, 

 but not with any degree of success. Their plan was to make 

 towards Carnival-time a deep hole, put fermenting material in 

 the bottom, and cover the top with boards and straw. By this 

 means in a fortnight or three weeks they obtained flowers 

 which had lost a portion of their redness, but which were far 

 removed from the snowy purity of those produced at the 

 present day. 



When hot water began to be successfully used for heating 

 plant-houses a new era commenced in the Lilac industry, and 

 in the winter of 1858 Paris society had its floricultural sensa- 

 tion in the pure White Lilacs, grown by M. Laurent, a Parisian 

 florist. His plan was to take bushes from the open ground, 

 plant them in a house which was kept day and night at a tem- 

 perature ranging from 86° to 95° Fahrenheit, and under these 

 conditions it took less than three weeks to get flowers. 

 Madame Furtado, at the Chateau de Roquencourt, and M. 

 Lavall^e, at the Chateau de Segrez, among others, began to 

 force Lilacs, and the latter, during his Presidency of the 

 Societe Nationale d' Horticulture de France, exhibited to the 

 Society perfectly White Lilac which had been produced in a 

 fortnight in full light in a house heated from 95° to 105° 

 Fahrenheit. 



The Marquis de la Fert^, Chateati du Marais, tried the culti- 

 vation in an Orchid house (in full light), with a temperature of 

 from 59" to 68° Fahrenheit, but the flowers did not change 

 markedly in color ; the heat was insuificient, and the same 

 results were noted at Segrez whenever the thermometer was 

 not allowed to rise above 68". Even in the dark, with com- 

 paratively low temperature, flowers become rose-tinted. So 

 far M. Hiring. ^ 



A few words may be written, however, about forced colored , 

 Lilacs. As is evident enough from previous remarks, the].. 

 bushes must not be suljjected to nearly so much heat if nor-^ 

 mally-tinted flowers (and for these, too, there has arisen ajfe 



large demand) are required. For pot-culture it is best to graft 

 or bud the desired varieties on stems of Ligustrum ovalifolium 

 or of L. vulgare. The plants thus treated make short, stubby 

 growth, and set very freely, but they will not bear early forc- 

 ing. Syringa Chinensis makes a delightful pot-plant, and this 

 species it is usual to bud on two-year-old seedlings of the com- 

 mon Lilac {S. vulgaris). This operation takes place at the end 

 of July. The next spring, as soon as the growth is as long as 

 the finger, it is stopped, and by autumn a fine head is formed. 

 Early the following spring the little trees are potted and the 

 pots plunged in the open ground. An abundant water supply 

 is necessary to induce a vigorous growth. In the middle of 

 July the pots are taken out of the ground and less water given, 

 in order to ripen the shoots. In November the pots are cov- 

 ered with some material to prevent frost from breaking them, 

 and the plants are ready for removal to the forcing-house as 

 required. G. Nicholson. 



Kew, February. 



Cultural Department. 



Hybridization of Gladioli. 



IN 1885 I prepared to raise Gladiolus-hybrids by planting a 

 row of the species G. purpureo-auratus among rows of 

 Gandavensis varieties for the sake of convenience in hybridiz- 

 ing the flowers. Similar plantings of G. dracocephalus were 

 made. Many flowers of G. purpureo-auratus and of G. draco- 

 cephalus were used as the pistillate parents. Some hybrids 

 were attempted in the reverse order, using Gandavensis varie- 

 ties as the pistillate parents, with but little success, and as the 

 resulting seed was not kept separate, no notes can be given 

 on this cross. The stamens were removed from all flowei's to 

 be hybridized while in the condition of unopened buds. The 

 pollen was removed from the cells of the anthers with a sharp- 

 pointed sflck, and transferred directly to the stigmatic surface. 

 This, in practice, was found the simplest method with Glad- 

 ioli, although with most plants a camel's hair brush is best. 



The hybridized seeds were planted in April, 1886, in shallow 

 boxes, and so grown throughout the summer. About mid- 

 summer, when the leaves attained a considerable height, fine 

 sifted cow-manure was spread over the soil in the boxes to 

 the depth of half an inch or more. This proved beneficial 

 as a mulch and source of hquid-manure at each watering. 

 In autumn the bulbs were sifted out of the earth and kept in 

 boxes, as they have been in succeeding winters. The second 

 year the seedlings were planted thickly in rows in the open 

 ground. 



I was informed by Mr. W. E. Endicott, who has had large 



experience with 

 ■^ B hybrids of G. pur- 



pureo-auratus that 

 flowers not artifici- 

 ally fertilized would 

 yield hybrids when 

 the plants are grown 

 near to Gandavensis 

 varieties. There- 

 fore, the artificially 

 fertilized and natu- 

 Fig. 95.— Diagram of the Perianth of Gladiolus. rally fertilized seeds 



were planted as one lot. The seed proved highly fertile, and 

 yielded as many plants as do seeds of ordinary Gandavensis 

 varieties. 



About twenty-five hybrids of G. purpureo-aiiratus bloomed in 

 1887, the second year from seed, and were essentially similar 

 to those which bloomed last summer. Many bulbs accident- 

 ally overlooked when digging in the autumn of '87, grew finely 

 last summer, which is strong evidence of the hardiness claimed 

 for the hybrids, as the winter of '87-'88 was extremely severe. 



During the summer of 1888, 175 purpureo-auratus hybrids 

 bloomed for the first time, and careful notes were taken of 

 each plant. 



Before discussing the hybrids, a few preliminary notes 

 are necessary. In the Gandavensis varieties (the ordinary 

 Gladioli of gardens) the segments of the corolla are arranged 

 on two anthotaxic* plans. The first and most numerous 

 arrangement is that shown in A fig. 95. The uppermost seg- 

 ment of the perianth is without, overlapping the adjoining 

 segments ; the lowermost within, embraced by its contiguous 

 segments ; the upper pair of laterals are overlapped by the lower 

 pair of laterals; the lower pair of laterals overlap their adjoining 

 , segments. The other arrangement of the segments is shown 

 iin B fig. 95. The uppermost segment overlaps the adjoining 



% * "Anthotaxy, denoting flower arrangement. A name formed on the analogy to 

 gphyllotaxy, or'leaf arrangement." Asa Gray, " Structural Botany," Part I., p. 141. 



