Guarianthe (Cattleya) aurantiaca is one of the smallest flowering of the Cattleya group. It has recently been moved into the group Guarianthe, but is better known as the Orange Cattleya. Native to Mexico, El Salvador, Honduras and Guatemala it grows as an epiphyte or lithophyte. They normally grow as small to medium plants, but can reach 15 inches, or 30 centimeters, tall with an inflorescence of 4 inches, or 10 centimeters.
The normal flowering season is in the spring in its native habitat, but fall for those plants grown in the northern hemisphere. The flowers are held in a cluster with up to 15 flowers per inflorescence and are 1-1.5 inches, or 3-4 centimeters, in size. There are two main varieties, the bright orange and a yellow which can vary from lemon to cream. You should be careful when buying one of these plants to try to see a flowering plant since some varieties will produce flowers which do not open fully and are not as pleasing as those which present well. Most plants available commercially have been bred for open flowers, but be sure to ask. This is one of the few Cattleya Alliance species which will self-pollinate, especially the ones which produce the half open flowers.
Due to its wide range in nature, this is an extremely adaptable species as far as temperature range which is generally considered to be intermediate to cool growing, but will tolerate warmer temperatures with good air circulation. It requires high light during its growing season in order to produce blooms. The native habitat is very humid with abundant rainfall, so the plant does not like to be dry long but the roots will rot if left for long periods with wet media. Small pots with quick draining medium or mounting is the best choice as well as semi-hydroponics.
This is one species which requires a dry winter rest with cooler nights in order to bloom well. They will tolerate temperatures to 50 degrees Fahrenheit, or 10 degrees Centigrade. The rest period in winter should be for approximately 4 months, from December through March, with reduced watering and fertilizer but the plants should not be allowed to be completely dry during this period. Humidity should remain high throughout the year.
This species produces a natural hybrid with Guarianthe skinneri called Guarianthe guatemalensis is a very pleasing plant to grow also with a wide range of colors. The cross is a very large plant which produces very impressive specimen plants.