ORCHIDS 



ORCHIDS 



2397 



n a ting, through the soil becoming sour or through 

 fungi. When thus attacked they should be transferred 

 to other pots or baskets not infested. 



A newly germinated seedling of Phaius hybridus is 

 shown in Fig. 2669. Fig. 2370 is of a three-months-old 



seedling of Cypripedium 

 insigne var. Sanderse, in 

 proper condition to be 

 transferred to a pot; Fig. 

 2671, eight -months -old 

 plant of Phaius Wal- 

 lichii; Fig. 2672 a twelve- 

 months-old hybrid cat- 

 tleya (C. intermedia x C. 

 laUata) ; Fig. 2673 a 

 2673. Thirteen months from seed, cypripedium thirteen 

 (Cypripedium.) months old; Fig. 2674 a 



two-year-old hybrid be- 

 tween a cattleya and laelia (C. intermedia x L. prsestans). 

 The raising of orchids from seed shoud be encour- 

 aged, and should enlist the energy of every orchid-cul- 

 turist, not necessarily for the production of hybrids, but 

 also for the reproduction of rare species and varieties, 

 and to save a number of species that are fast decreasing 

 or becoming extinct in their native homes. Aside from 

 the financial inducement offered the commercial grower, 

 it will prove instructive to the botanist and afford 

 pleasure and pastime for the amateur. 



Diseases. 



Orchids are subject to many diseases. Those having 

 importance from a cultural standpoint and most 

 troublesome to the grower are known as wet-rot, dry- 

 rot and spot. Wet-rot is brought on by an overmoist or 

 stagnant atmosphere, and is usually first detected by 

 a semi-transparent appearance of the parts affected, 

 which soon become dark brown. It spreads slowly 

 along the tissue. If noticed at the commencement, it 

 can be readily checked by slitting the epidermis with a 

 sharp knife and removing the plant to a more airy 

 position in the house for a few days. 



Dry-rot is caused by a fungus which attacks the 

 rhizome of the plant. It is often produced through 

 burying the rhizome or base of the plant with compost. 

 Cypripediums are subject to it. Large, healthy growths 

 when attacked quickly show a sickly pale color in the 

 foliage, which, on examination of the base, will be found 

 discolored, and with a light brown appearance. If the 

 portion attacked is quickly removed with a sharp knife 

 it will usually give no further trouble; otherwise it will 

 travel through the entire rhizome and destroy the plant 

 in a very short time. 



Spot comes from various causes: the appearance of 

 small dark brown spots on the succulent leaves and 

 pseudpbulbs is usually an indication of cold and over- 

 watering. Spot also arises through weak tissue, espe- 

 cially in phalsenopsis, saccolabiums and angrsecums 

 during winter, which have been grown too warm, shady 

 and moist. The affected parts should be slit with a 

 sharp knife and a little flowers of sulfur should be 

 rubbed over the wound. When they make new growth 

 the plants should be placed in a brighter and more airy 

 position to induce a better growth. The brown dots 

 which make their appearance on the leaves, especially 

 at the apices and on new growths of deciduous and 

 plicate-leaved species, indicate either lack of sufficient 

 water at the roots or an over-dry atmosphere, both of 

 which conditions can be easily changed. 



Snails and insects. 



Orchids are attacked by many forms of snails. Insect 

 pests are a great annoyance to the cultivator. They 

 can be kept in subjection only by constant attention. 

 Slugs and shell snails are very destructive. If allowed 

 to increase they devour young shoots, roots and flower- 

 buds. The best means of capturing them is to place 



saucers of dry bran on the shelves among the pots, 

 and look them over morning and evening. By this 

 means many will be destroyed. Various species of scale 

 insects attach themselves to the leaves, pseudobulbs 

 and rhizomes of nearly all species of orchids, and can 

 be eradicated only by the use of a soft brush and wash- 

 ing with a sponge and water. A little whale-oil soap 

 added to the water is of great assistance, and also useful 

 in destroying red-spider, green-fly and yellow-fly. Black 

 and red thrips attack the young growths of many 

 species and often become very troublesome. Fumiga- 

 ting the houses with tobacco stems lightly about three 

 tunes during the week will soon cause them to disappear. 

 Fumigation is also a sure remedy for green-fly. 



The cattleya fly is very injurious to young growths 

 of cattleyas, laplias and some epidendrums. The flies 

 lay their eggs in the very young growth at the base, 

 causing an enlargement which is easily distinguished. 

 The only remedy is to remove the growth and burn it. 

 The mature fly can be eradicated by fumigating the 

 house with tobacco stems about three times each week 

 during early spring. 



The dendrobium beetle larva burrows in the stems of 

 various species of the genus, and is detected by a small 

 discolored spot. There is no remedy, except to cut 

 away and destroy the parts attacked. A pest much more 

 to be dreaded is the dendrobium mite, which perforates 

 the canes and rhizomes of dendrobiums and many other 

 orchids, laying a number of eggs in each perforation. 

 On hatching, these eat away a part of the plant around 

 them, causing that portion to decay. They can be 

 found only by careful and close observation, and this 

 often after the plant is beyond redemption. There is 

 no remedy but cutting them out, and unless the plant 

 attacked is valuable it is 

 best to burn it and keep 

 the pest from spreading. 



Mealy-bug is usually not 

 very troublesome to orchids. 

 It is readily seen and de- 

 stroyed without much injury 

 to the plant. 



Roaches are usually very 

 troublesome, and hard to 

 eradicate, as they feed at 

 night and remain hidden 

 through the daytime. They 

 destroy roots, growing shoots and young flower-buds 

 and scapes. Bran, powdered sugar and paris green, 

 mixed together and placed around the houses in saucers, 

 will usually keep them in subjection, and they should 

 be hunted down at night by the aid of a lantern. 

 Many can be caught in this manner. 



Sow-bugs or wood-lice are usually common in every 

 part of orchid houses, pots and baskets. They do a 

 great deal of damage to young leaves, roots and the ten- 

 der portions of flower-scapes. The paris green mixture 

 used for roaches is very effectual in reducing their 

 number, but it is impossible to be entirely freed from 

 them. ROBERT M. GREY. 



Hardy orchids. 



Many of our native species of orchids are very beauti- 

 ful, and some are easy of culture, given suitable situa- 

 tions as to soil, moisture, and, in some instances, shade. 

 It seems almost impossible to tame these wildlings, in 

 the sense of making them border plants; the desirable 

 situations are shady moist places in the woods for the 

 habenarias, Galeorchis (Orchis) spectabilis, listera, and 

 goodyera. Moisture, however, does not mean a stag* 

 nant condition of the soil, but slight depressions that 

 are preferably above the level of surrounding soil, so 

 that drainage is secure. 



The two-leaved habenarias, such as H. Hookeriana, 

 H. orbiculata, H. blcphariglottis, and H. dilatata all occur 



2674. Two-year-old hybrid 

 between a cattleya and laelia. 



