Odontoglossum Andersonianum, _Reichenbach fil._, in _Gardeners’ Chronicle_, 1868, 599; _Id._ 1872, 41; _Floral Magazine_, 2 ser., t. 45.
The charming _Odontoglossum Andersonianum_, supposed to be a wild mule between _O. Alexandræ_ (_crispum_) and _O. præstans_ or _O. gloriosum_, is one of the many prettily spotted Odontoglots which have been introduced into our collections during the past few years, and among which new varieties are continually appearing. One of the best forms of this plant which has come under our notice is that represented in the accompanying plate, prepared from a very beautiful specimen which bloomed last year among many other fine Odontoglots, well cultivated in the collection of Messrs. William Thomson & Sons, of Clovenfords near Galashiels.
The _Odontoglossum Andersonianum_ is a compact-growing plant, with pyriform pseudobulbs two to three inches high, pale green leaves, and gracefully drooping branched flower-spikes about two feet in length. The sepals and petals are at first creamy white, spotted with purplish brown, the lip being also white, but less heavily spotted. The plant is of free-blooming habit, the flowers continuing fresh and perfect for a period of five or six weeks. It is exceedingly difficult to recognize this form until it produces its blossoms, as its growth is remarkably similar to that of _O. Alexandræ_. Indeed there are many forms and varieties of this particular group which it is impossible to recognize until their flowers are seen; and, though cultivators may sometimes feel assured of the identity of individual plants, the production of flowers not unfrequently proves them to be mistaken.
_Odontoglossum Andersonianum_ requires the same treatment as _O. Alexandræ_ and other cool Orchids, also the same amount of water. The plants must have good fibrous peat to grow in, and plenty of drainage, as they need to be freely supplied with water all the year round, and this, if allowed to become stagnant, would prove very injurious to them. The material in which they are grown must also be clean and sweet; and though they must never be over-potted, sufficient space should be allowed for their roots. We have sometimes seen Odontoglots in pots far too large for them, and though this may tend to make the plants more important-looking, yet it will eventually spoil them, as the larger amount of soil becomes soddened with water, and this produces rotting of the roots.