SYRINGA 



SYRINGA 



3299 



About three to four weeks is required to force the 

 plants into bloom with the temperature recommended 

 below. The first days after bringing the plants into the 

 forcing-room, a temperature of 55 to 60 may be given, 

 gradually rising to 78 to 88 and maintained as equally 

 as possible until the panicles are fully developed and the 

 first flowers begin to expand; then the temperature is 

 lowered to 60 to 66, and when the panicles are about 

 half open the plants are tranferred to a cool greenhouse. 

 Hardening-off is essential to ensure good keeping quali- 

 ties of the flowers. The red-flowered varieties are often 

 forced in darkened rooms in order to have the flowers 

 blanched or only slightly colored. The shade of color 

 depends entirely on the time when full light is given 

 and also on the temperature. Show plants in pots 



3761. Syringa vulgaris. The 

 common lilac. ( X ,' 3) 



should be grown in full light to have the foliage well 

 developed. When the temperature is higher than 76, 

 frequent syringing is necessary. It is. of course, pos- 

 sible to force lilacs in a lower temperature, and this 

 will even be advisable if the longer time required does 

 not count. Full advice for commercial lilac-forcing 

 is given by Fr. Harms in "Flieder und Asparagus," a 

 book devoted almost exclusively to lilac-forcing. 



Interesting experiments recently conducted have 

 shown that the lilac is more readily forced when the 

 plants are subjected to the influence of ether during 

 forty-eight hours shortly before forcing. An account 

 of these experiments by W. Johannsen is entitled "Das 

 ^Etherverfahren beim Friihtreiben mit besonderer 

 Beriickrichtigung des Flieders." That the ether has a 

 particular effect on the metamorphosis and regenera- 

 tion of the albuminoids in the plant has been stated 

 recently by other botanists also. 



Lilacs may be propagated by seed, which is sown in 

 spring. This method is usually practised only with the 



209 



more common typical species. The many varieties and 

 rarer kinds are usually propagated by greenwood cut- 

 tings under glass in June (or in early spring from forced 

 plants), by hardwood cuttings, by grafting, and also by 

 suckers and division, especially in the case of S. chinen- 

 sis, S. persica, and S. vulgaris. As a stock, S. vulgaris is 

 mostly used and sometimes ligustrum. S. japonica will 

 probably prove to be a good stock. S. viUosa, though 

 readily growing from seed and of vigorous habit, is not 

 to be recommended. Budding in July and August is the 

 most extensively practised method. Grafting is done 

 either in April or May in the open or in February or 

 March in the greenhouse on potted stock. Almost any 

 kind of grafting may be employed as the lilac unites 

 readily. Crown-grafting is to be preferred in order to 

 avoid the troublesome suckers. Plants intended for 

 forcing but deficient in flower-buds are sometimes 

 grafted in October or early in November with branches 

 well set with flower-buds and forced in January or later. 

 Forcing lilacs. Most of the lilacs used by American 

 commercial florists for forcing are imported. Care 

 should always be taken to procure pot-grown plants, 

 that is, plants that have been grown in pots the previous 

 summer. The florist who wishes to grow his own 

 plants should lift them in the field in April or before the 

 growth starts and pot them without losing much root. 

 Plunge them out-of-doors during summer and give 

 them plenty of water. This treatment will insure a good 

 growth and the check the plants receive from lifting will 

 induce them to form new flower-buds. These plants 

 will force with the greatest certainty. It is well to allow 

 five weeks for the earliest forcing. A strong heat is 

 necessary, beginning at 60 for the first few days 

 and increasing to 75 to 80, with a daily watering 

 and syringing several times. After the flowers begin to 

 open, the syringing can be discontinued and when 

 fully expedient the plants are better 

 removed to a coolhouse, where they 

 will harden off and be much more 

 serviceable when cut. As the sea- 

 son advances, say March and 

 April, less heat is needed. They 

 will then force in any ordinary 

 house where the night temperature 

 is about 60F. The Persian lilac, on account of its 

 abundance of bloom and delicate truss, is very 

 desirable, but this must be forced almost in the 

 dark to produce white flowers. Marie Legraye is 

 for all purposes the most useful lilac which has been 

 used for forcing. (Wm. Scott.) 



affinis, 7. 



alba, 7, 9, 10, 11, 13. 

 amurensis, 12, 13, 14. 

 argentea, 14. 

 aurea, 3. 



aureo-variegata, 3. 

 Bretschneideri, 2. 

 cserulea, 9. 

 chinensis, 10. 

 dubia, 10. 

 duplex, 10. 

 emodi, 2, 3. 

 erimia, 2. 

 filicifolia, 11. 

 Giraldii, 7. 

 Henryi, 2. 



INDEX. 



hyacinthiflora, 8. 

 hybrida, 2. 

 japonica, 14. 

 Josiksea, 1, 2. 

 Julians, 6. 

 laciniata, 11. 

 liffustrina, 13. 

 mandshurica, 13. 

 marlyensis, 9. 

 metensis, 10. 

 oblata, 7, 8. 

 ovalifolia, 5. 

 pallida, 1. 

 pekinensis. 12. 

 pendula, 12. 

 persica, 11. 



pinnata, 11. 

 plena, 8, 9. 

 pteridi folia, 11. 

 pubescens, 5. 

 reflexa, 4. 

 rosea, 2. 



rothomagensis, 10. 

 rubra, 1,9, 10, 11. 

 saugeana, 10. 

 sibirica, 13. 

 Steencruysii, 11. 

 varina, 10. 

 villosa, 2, 3, 5. 

 violacea, 9. 

 vulgaris, 9. 



KEY TO THE SPECIES. 



A. Tube of corolla much longer than 



calyx; anthers sessile, not exserted. 

 B. Panicles on leafy branches, usually 



terminal: Ivs. whitish beneath. 

 c. Infl. upright. 



D. Anthers not exserted. 



E. Stamens inserted near the mid- 

 dle of the tube; corolla-lobes 

 nearly upright ........... 



1. Josikaea 



