Cmtober 26, UK)7 



HORTICULTURE 



637 



Three Good Odontoglossums 



Odontoglossum grande, Lindl Guatamala 



The commercial grower of orchids, who has facilities 

 for handling odontoglossums would find 0. grande, 

 0. Sehlieperianum and 0. Insleyei. three useful and 

 easily grown subjects. Jn some collections these species 

 are represented by poor sickly, shrivelled plants, and 

 they are usually considered hard to grow. They are, 

 however, all very easy, providing a suitable compart- 

 ment can be found for them while they are making their 

 growth in summer. In nature they are found at high 

 altitudes in woody moist situations in Central America 

 where the rainy season is long and the percentage of 

 atmospheric moisture high, relieved only by frequent 

 cool winds. In a coo), moist gTeenliouse where the tem- 

 peratiire can be kept do'mi without -excessive shade, 

 these conditions can be fairly well maintained. These 

 species do not suffer so much from the humid heat of 

 summer as the Colombian species do. 



A good circulation of air, which should not be allowed 

 to become dry, is important. Stagnant corners, or 

 positions where the circulation is not perfect, such as 

 a shelf against a wall, should be avoided. The plants 

 should be hung as near to the glass as possible. If the 

 two extremes — stag-nation and a dry atmosphere — are 

 guarded against, the result should be satisfactory. 



0.' grande, often called the "'baby orchid," is the 

 best of the three; the flowers ajjpear in late fall and are 

 extremely handsome, measuring 5 to G inches across. 

 The flowers on the accompanying photograph measure 

 fa 1-2 inches in diameter. The color of the sepals and 

 petals is rich yellow barred with reddish brown. The 

 tips of the petals are pure yellow; the lip is cream 

 blotched with brown. 



0. Sehlieperianum is very similar to 0. grande; the 

 flowers are smaller and appear in August and Septem- 

 ber. 0. Insleyli also has smaller flowers which appear 

 in winter; the tlowers are similar to the two preceding 

 species but instead of being barred are spotted and 

 blotched with brown. 



In each case the flower spike arises from the base of 

 the newly formed pseudo-bulb and as soon as the 

 growth is mature the plant should be kept fairly dry 

 until new growth commences in spring when, after root 

 action has fairly commenced, a liberal supply of weak 

 stimulant may be given. The best rooting medium for 

 this class of orchid and all which have a decided period 



of rest is fern fibre without moss. Shallow pans are 

 the most suitable receptacles. 



Gimkgo bilobo 



Believing that the readers of Hokticulture would 

 be further interested in' the valuable tree heading these 

 notes I have secured photographs of at least two dis- 

 tinct forms of same. The one taken at Washington, 

 . D. C, was received through the courtesy of Mr. Peter 

 Bisset, president of the Florists' Club of that city. It 

 was taken from the roof of Department of Agriculture 

 Building. (See frontispiece.) 



It will readily be seen that wliile the growth of the 

 tr-ees has an upright tendency, they — none of them — 

 could be classified as pyramidal in form, as is exempli- 

 fied by the Lombardy poplar — Fopulus pyramidalis. 

 This i^hotograph bears out what was my belief respect- 

 ing the distinctions betweeir what is considered the 

 type of the Ginkgo and those pyramidal forms as seen 

 in those trees near to Horticultural Hall, Fairmount 

 Park, Philadelphia. 



In another photograph which was taken in Girard 

 College grounds by my assistant, Mr." B. Thomas, 

 two Ginkgos are seen; both may be considered 

 the general type, yet both are quite distinct. 

 It would be worth Mr. Chandler's while to stop off 

 at the zoological gardens sometime and examine a 

 Ginkgo gi'owing just outside the grounds and not very 

 far from the entrance and he will, I think, find unmis- 

 takable evidences that this particular tree was grafted — 

 for the upper part is of the same pyramidal form as 

 are those in Fairmount Park, but the lower limbs are 

 decidedly sprawling, showing beyond the shadow of a 

 doubt that these sprouts were allowed to grow belovv 

 where the union of scion and stock had been effected. 



The more I see of the Ginkgo the more am I im- 

 pressed with the idea that it is not only one of the best 

 street trees but it is the very best for that purpose. 

 There are three Ginkgo trees in front of No. 1505 North 

 Broad street, Philadelphia — which is near Jefferson 

 street — and I do not hesitate to say that they present 

 the most satisfactory appearance of any trees along 

 that thorouohfjire. These, while they have an upright 

 growth and represent the type, are very different from 

 the fastigiate forms seen in Fairmount Park. I wish 

 professional wTiters for the horticultural press would 

 drop the Carolina poplar from their lists of street trees 

 and recommend in its place the Ginkgo. The reason 

 given for recommending the poplar is because it is 

 quick growing. Thi^ in many instances is a decided 

 disadvantage for, in order to keep it within reasonable 

 bounds, after being plantexl a few years, it has to he 

 pruned and that makes the tree expensive, for it costs 

 at the lowest calctilation 50 cents a year to keep it 

 shapely, and another disadvantage is that as soon as it 

 has finished putting forth its leaves in the springtime 

 thev commence to fall, whereas the Ginkgo retains its 

 foliage until the first frost. Among quite a number of 

 poplars there are in Girard College grounds and on the 

 oiit-ide T3avement three which put forth their leaves 

 somewhat later in the spring than do the major- 

 ity of our trees, nor do they lose their leaves so early in 

 the Slimmer, retaining them quite late. Is this a selec- 

 tion or what? They are distinct in other respects 

 besides those mentioned but it would be difficult to 



