344 ORCHIDS 



Odontoglossum. 



test of open-air culture. Although it is not intended to 

 advocate the open-air culture of exotic Orchids, it should 

 be distinctl)' understood that the genus Odontoglossum is 

 purely alpine, no single species having hitherto been found 

 low down the mountains, or in hot regions. The plants 

 will not exist long in a healthy condition if kept in 

 hot, close houses : this should be sufficient to recommend 

 them to the notice of amateurs. Thej' enjoy a cool, moist 

 atmosphere all the year round, and, unlike the majority 

 of Orchids, do not, except in a few isolated instances, 

 recjuire a dry season ; indeed, many of them grow freel)^ 

 during the winter months, and these must never be 

 allowed to get dry. For their culti\-ation, we prefer a 

 house with a northern aspect or one running from north 

 to south. In bright weather shading is essential, especially 

 during the summer ; but in winter, during very severe 

 weather, no harm w'lW be done to the plants if the thermo- 

 meter falls as low as 45deg., whilst in hot summer weather 

 the maximum temperature ought not to exceed /Odeg. 

 The normal temperature required under ordinary conditions 

 is 5odeg. in winter and SSdeg. in summer. Above all things, 

 a free current of air is indispensable to their well-being. 

 Do not sprinkle them overhead much with the syringe, 

 but preferably keep the air well charged with moisture 

 by pouring water upon the stages and floors ; and, as the 

 temperature must be considerably lower at night than 

 during the day, the condensation which this produces will 

 be most beneficial to the plants. 



Although Odontoglossums grow natural!}' upon the 

 trunks of trees, or in the vegetable debris that is lodged at 

 the base of the branches, we have never known them thri\-e 

 for any length of time when grown upon blocks, probably 

 because evaporation takes place too rapidl}', and the roots 

 get withered up. Some of the species send their roots 

 through and about the various mosses that clothe the 

 forest-trees in the humid mountain regions where they 

 most abound, adhering so slightly to the branches that 

 a well-known collector once said that he found he could 

 bring immense quantities of 0. crispuin down to the 

 ground b)' merely throwing his lasso into the branches 

 upon which the plants grew, and then pulling it towards 

 him. 



