The following is an attempt to compile a complete list of the blue Cattleya and Laelia species, accompanied by various notes, for reference for those individuals interested in this color line. It includes varieties mentioned by previous authors and recent introductions. Some of these varieties are no longer in cultivation or their whereabouts are unknown or questionable. These are marked with an asterisk (*) in the listing.
Several bluish forms of C. amethystoglossa have appeared of late as a result of a selfing. They have blue-lilac spots and lip with off-white sepals.
Cattleya bowringiana has five blue forms. Of the first three, the clearest is var. concolor. It has no lavender in the flower. It is blight blue throughout with a darker bar in the lip. Variety coerulescens has been selfed, and some fine blue forms are appearing among the progeny.
Two forms of blue C. gaskelliana are suspected of being synonymous, and possibly a third. The two are var. coerulea and 'Blue Dragon'. The latter has off-white sepals with dark blue veins in the throat, yellow-orange eyes and a lavender bar overlaying the solid dark-blue lip. Its new growth takes on a pinkish color similar to that exhibited in var. coerulescens progeny, C. Ariel coerulea.
Cattleya harrisoniana var. azul has been described as blue lilac with darker coloring in the lip. Its growth shows blue-lavender spotting, so there is probably some definite signs of lavender in the flower.
Cattleya intermedia is one of the most widespread of the blue species, with several varieties having blue lips. The most common are listed. The sepals and petals are white to off-white.
Cattleya labiata var. coerulea is well known but not common in cultivation. There are about a dozen different clones, one of which will be discussed. It is a little difficult to grow. The flowers are off-white to light blue, with darker veining in the lip and gold throat and eyes.
Cattleya maxima has two synonymous blue clones. This plant was one of several wild collected plants imported from Ecuador by the late Bob Grinder. Upon blooming, it had a strong blue cast. It did not get a varietal name until it had been divided and pieces given to several persons. Thus the confusion. It varies in color from bluish lavender to lavender. It has been used as a parent with Lc. Blue Boy. Most of the seedlings show strong indications of lavender.
There are several blue clones of C. mossiae, and quite possibly some are synonymous. The variety 'Reineckiana, Blue Lip' (R.B.L., in general reference) has yellow eyes and throat with off-white sepals and blue-pink veins in the throat when grown warm, and fine, medium-blue-with-dark-blue veining when grown cool.
Cattleya trianae var. coerulea shows bluish tones but is washed-out. Variety 'Blue Bird' is the darkest but still exhibits a great deal of lavender. It is difficult to grow and its progeny show distinct signs of lavender.
Cattleya walkeriana var. coerulea is one of the most interesting of the blues. Its growth shows no coloring, but the bloom spike has tiny dots of dark blue-pink. When the flower opens, it is off-white and quickly changes to e fine blue with light lavender or pink undershading. It is nearly concolor, having only two or three small, dark veins in the lip. There is a lemon-yellow disc overlaid on the forelobe of the lip.
There are about six different clones of C. warneri var. coerulea. Generally speaking, sepals and petals are a fine medium blue, with a solid dark lip. It is one of the easiest to grow and one of the loveliest of flowers.
Laelia anceps var. veitchiana has strong suggestions of blue in the near-white sepals. The lip is the same color, but edged in a darker clear blue. During its early stages, the new growth shows a little bluish color.
Laelia autumnalis 'Blue' was listed in a Missouri Botanical Gardens publication a few years ago, but it has been misplaced in their collection or possibly lost.
Laelia crispa var. coerulea has been described as having off-white sepals and a fine, dark-blue lip. One small division is all that is known to exist, and it is not doing well.
Laelia perrinii var. coerulea is two different clones. One has been described as blue-lavender with darker lip. The other has off-white sepals and a blue lip. Neither are known to be in cultivation in this country.
There are three distinct clones of L. pumila var. coerulea. They are perhaps the darkest of the blues. Tepals are medium to dark blue with an even darker lip. Laelia praestans 'Gatton Park' may be included here. It was used as a parent of Lc. Parysatis coerulea and since disappeared.
Laelia purpurata var. Werkhauserii is the most well-known of the blue Laelias. There are numerous jungle-collected clones and several selfings. It has white sepals with a dark blue to blue-lavender lip.
Perhaps as time passes, more blue species will come to light or some of those "lost" will reappear. If the reader knows of others to add to this list, please do so.
(American Orchid Society Bulletin, Vol. 35, No. 10, October, 1966, pp. 834-835.)