10 



CYPRIPEDIUM. 



The geographical distribution of the Cypripedia included in this section 

 sufficiently indicates the temperature in which they should he cultivated 

 in the glass houses of Europe, which is that of the East Indian house 

 for most of the species and hybrids, that is to say, a house in which 

 the night temperature in winter is never allowed to sink below 15° — 

 12° C. (60° — 55° F.), with a gradual rise as the season advances, to 18° — 

 21° C (65 — 70° F.), at which it should be maintained from May to 

 August. The day temperatures by fire-heat alone shoidd be about 3° C. 

 (5° — 6° F.) above those of the night. A few species, chiefly insular, 

 including Cypripedium concolor, C. niveum, C. Godefroyce, 0. philippi- 

 nense, etc., thrive best in the higher temperature of the Phalsenopsis 

 house ; on the other hand, C. insigne, C. venustum, C. Fairieanum, and 

 the hybrids obtained from them may be cultivated in the intermediate 

 house. 



It is evident, too, that as the great majority of the tropical species 

 occur within the equatorial belt, or sufficiently near it to come under the 

 like climatic conditions, of which the most noteworthy are the remark- 

 able uniformity of temperature and the high degree of atmospheric 

 humidity throughout the year, there is practically little or no interruption 

 in their vegetation in their native homes. But when transferred to the 

 glass houses of this country, it is equally clear that such an uniformity of 

 climatic conditions cannot be so strictly maintained by artificial means 

 owing to the succession of seasons ; hence there is, at least, a partial 

 cessation of growth if not of absolute rest during the coldest months of 

 the year. Advantage should be taken of the recommencement of their 

 growing seasons to re-pot the plants not then in flower ; they should be 

 potted in a compost of sphagnum moss and fibrous peat in about equal 

 proportions ; the drainage should be quite free ; it should consist of clean 

 broken crocks with which the pots should be filled to one-half or even 

 to two-thirds of their depth, according to the size of the plants. As 

 the roots of Cypripedium grow vigorously, ample provision should be made 

 for their development. 



The plants must at no time be suffered to get dry at their roots 

 during their growing season ; a high degree of moisture must be 

 maintained in the atmosphere of the house, the amount and frequency 

 of the watering and the sprinkling of the floors, etc., of the house 

 being, of course, regulated by the season of the year and the external 

 circumstances of weather, etc. The ventilation must also be regulated 

 according to external influences, but it should at all times be as free 

 as is consistent with the well-being of the plants, avoiding cold draughts 

 and sudden changes of temperature. In the summer months the plants 

 should be protected by shading from the direct rays of the sun ; a 

 very slight exposure to direct sunlight at that season causes the foliage 

 to change colour ; this is particularly the case with those species that 

 have tesselated leaves. 



