December 20, 1906. 



The Weekly Florists^ Review* 



341 



Vanda Caerulea* 



will carry ten to twenty flowers, occa- 

 sionally even more. They keep well, 

 either on the plant or in water. 



Yearly importations of these now ar- 

 rive each spring in America and any- 

 one who has any sale for orchids should 

 try at least a few. A good supply of 

 moisture in the growing season and drier 

 conditions in winter are essential. Plants 

 which have become too tall should have 

 the tops cut off with a sharp kjiife, 

 with some roots attached, and be placed 

 in small baskets, where they soon estab- 

 . lish themselves. W. N. C. 



COMMERCIAL ORCHIDS. 



[A paper read before the St. Louis Florists' 

 Club December 13, 1906, by G. H. Pring, of the 

 Missouri Botanic Garden.] 



Owing to the orchidacesB being such a 

 large and varied order, 1 intend to deal 

 only with the genera which have commer- 

 cial value, as, cattleyas, laelias, cypripe- 

 diums, odontoglossums, cymbidiums and 

 dendrobiums. 



Cattleyas and Laelias. 



These closely allied genera, with their 

 large and highly colored flowers, are 

 among the most popular, useful and 

 showy of all orchids. They are natives 

 of Mexico and Brazil, where they are 

 found in the ravines and valleys. In 

 these situations the plants affix them- 

 selves indifferently to the trunks and 

 branches of trees, or to the bare rocks 

 in the gorges of the mountains. In this 

 wild state scarcely any soil is found at 

 their roots, only a little moss and a few- 

 leaves which have fallen among the 

 stems. 



Notwithstanding the enormous extent 

 of territory over which the cattleyas 

 and laelias are spread, there is a similar- 

 ity in the climatic conditions, thus favor- 

 ing the horticulturist in being able to 

 cultivate them in the same greenhouse, 

 which is usually termed the cattleya 

 house. The most convenient is a spacious, 

 airy building, well ventilated, running 

 north and south. It is preferable to have 

 all orchid houses lie with this aspect to 

 obtain the full benefit of tSe sun, light 

 being one of the chief items in success- 

 ful orchid cultivation. In such a house, 



cattleyas and la'lias enjoy a temperature 

 ranging from 55 degrees to 60 degrees in 

 the winter and 60 degrees in summer, 

 with such increment by sun heat as cir- 

 cumstances admit. 



The compost should consist of peat or 

 polypodium fibre and moss, with an addi- 

 tion of cracked crocks, this keeping the 

 compost sweet. Ample drainage is also 

 an important item. Pots proportionate to 

 the size of the plants should be selected. 

 Overpotting, with the object of stimu- 

 lating the plants into more active growth, 

 is one of the greatest fallacies that can 

 be entertained in orchid culture. The 

 plants should always be potted above the 

 rim of the pot as much as possible to 

 prevent them getting water-logged, and 

 should be potted moderately firm. The 

 best time for repotting is when they be- 

 gin to emit their new roots, according 

 to the species. During the growing sea- 

 son these plants enjoy a plentiful supply 

 of water at their roots, with a slight 

 spraying overhead. "When the growths 

 are mature the water supply should be 

 gradually diminished until enough is 

 needed to prevent shriveling. 



The shading of the houses during sum- 

 mer should be of some thin material, 

 just enough to prevent injury to the 

 young growths. A plentiful supply of 

 ventilation during the summer is essen- 

 tial. » 



The best species commercially are: Cat- 

 tleyas Trianae, Mossise, labiata, gigas, 

 Percivaliana, and Warneri. Laelias 

 crispa, pumila, purpurata, autumnalis, 

 anceps and its varieties. 



Cypripediums. 



This is a widely distributed genus, na- 

 tive chiefly of northeast India, found on 

 the lower parts of the Himalayas, Burma 

 and the islands of the Malayan archipel- 

 ago, and also South Americai, which is 

 the home of the selenipediums. These 

 differ from the cypripediums in having a 

 three-celled ovary, and the latter a one- 

 celled, a difference, though, not strongly 

 marked in the inflorescence, the scapes 

 producing a succession of flowers, several 

 being open at the same time. 



Cypripediums, commonly called lady 

 slippers, are no doubt the easiest to culti- 



vate. More hybrids have been raised by 

 the hands of the hybridist than any other 

 genus, the seedlings flowering in the 

 course of two and one-half to three and 

 one-half years. When imported plants 

 are received it is advisable to lay them 

 out on damp moss, with a slight spraying 

 occasionally, to induce them to emit new 

 roots. They may be potted without fear 

 in a mixture of peat and moss in equal 

 parts, with a little charcoal. 



Such species as Spicerianum, bellatulum 

 and eoneolor enjoy an addition of fibrous 

 loam and crushed crocks. They should 

 be given a plentiful supply of water 

 during the summer, both at their roots 

 and leaves. Heavy shading during sum- 

 mer is necessary to prevent the leaves be- 

 coming yellow through the strong rays 

 of the sun. The temperature should be 

 kept as near as possible in the winter 

 from 60 degrees to 65 degrees and not 

 less than 65 degrees in the summer. Such 

 species as insigne, etc., enjoy an inter- 

 mediate temperature. A suitable time 

 for repotting is in spring, about March 

 being preferable. When the plants are 

 in full growth a little liquid manure 

 applied occasionally will be beneficial. 



Odontoglossums. 



This most popular genus of the cool- 

 house orchid is distributed throughout 

 the mountainous region facing the Pa- 

 cific, extending from Peru to the south- 

 ern p'ortion of Mexico. The Columbian 

 districts being very rich, yield the most 

 sorts. Odontoglossum crispum and O. tri- 

 umphans are quite common. It is quite a 

 common occurrence in the London sales- 

 rooms for such prices as $5,000 to be 

 paid for single specimens of O. Pit- 

 tianum. Although odontoglossums are 

 indigenous to tropical countries, they are 

 found at considerable altitudes, growing 

 on trees, etc. ; hence the majority are 

 better accomniodated in a cool-house, 

 where an abundance of moisture can be 

 obtained all the year round, combined 

 with a free circulation of air. 



The tropical heat here in St. Louis in 

 the summer is detrimental to the major- 

 ity of the cool-hduse orchids. Although 

 the Mexican species, such as, Odontoglos- 

 sum citrosmum, apiatum, cordatum, In- 

 sleayi, grande, Cervantesii and Eossii, 

 which need an intermediate temperature, 

 can be grown successfully with a little 

 attention. 



A good general compost for potting 

 odontoglossums consists of equal parts 

 of fibrous peat, fresh, Qhopped sphagnum 

 moss, with an addition of crushed crocks 

 and silver sand. The best time for repot- 

 ting is about the end of September, 

 or in the month of March, according 

 to the condition of the plants. Care- 

 ful watering is necessary after potting 

 to prevent the growths from damping 

 off, especially such species as Cervantesii 

 and Rossii. During summer a plentiful 

 supply of water is essential, both at 

 their roots and leaves. Heavy shading 

 is necessary for these cool-house plants, 

 lath roller blinds being the best, as they 

 can easily be manipulated. 



Cymbidiums. 



This is a popular, though not a large 

 genus of orchids, dispersed over the Indo- 

 Malayan region and Japan. 



The cymbidiums are of robust habit, 

 having stout pseudo-bulbs and thick, 

 fleshy roots, which are freely produced, 

 providing they have ample pot-room for 

 development. The compost should con- 

 sist of good fibrous loam and peat in the 

 proportion of two-thirds of the former 



