Perhaps the place to begin when discussing blue hybrids would be with the natural ones, of which there are two - both of Brazilian origin and having Laelia purpurata, no doubt variety Werkhauserii, as one parent.
The first, Laeliocattleya elegans 'Werkhauserii' (L. purpurata x C. guttata), came to these shores several years ago. Its sepals and petals are greenish white. The lip has a blue-lavender bar on the forelobe, which shades frosty blue further up the throat. It made its breeding debut crossed with Cattleya Ariel coerulea, to make Lc. Blue Boy.
Laeliocattleya schilleriana 'coerulea' (L. purpurata x C. intermedia) is the other natural hybrid. Its sepals are white with the forelobe of the lip being dark blue-lavender. This plant has been superseded by some superior forms of a fairly recent cross utilizing two fine blue varieties of the parents.
No one can overlook the groundwork done in producing the Gatton Park "tints" by Sir Jeremiah Coleman. Some of his original hybrids are still in cultivation. The most popular is C. Portia coerulea (C. bowringiana var. violacea x C. labiata var. coerulea). The color is light to medium blue with a darker lip. The lip has a dark lavender bar across it, as do most of the C. bowringiana hybrids. Size of the flower is around three inches. There are numerous varieties, some darker than others. In most cases this hybrid is difficult to breed, but it has and is being used for further hybrid work.
Another of Coleman's crosses, not as well distributed, is C. Ariel coerulea (C. bowringiana var. lilacina x C. gaskelliana var. coerulescens). The plant and flowers are about the same size as those of C. Portia coerulea. It blooms about the same time, but the flowers are generally darker. This hybrid is figuring greatly in today's breeding.
Laeliocattleya Parysatis coerulea (C. bowringiana var. lilacina x L. praestans [pumila] 'Gatton Park') has only been used for hybridizing in recent years. Its flowers are two- to two-and-a-half inches across, medium to dark blue with a dark, solid lip, again exhibiting the lavender bar. It blooms two or three times a year with three or four flowers per spike and Is rather easy to grow.
Brassolaeliocattleya Victoria coerulea (C. Portia coerulea x Blc. Antoinette) is rather interesting, as for its background. Brassolaeliocattleya Antoinette is C. Portia (coerulea ?) with Bl. Helen. The latter is B. digbyana x L. tenebrosa. The outcome in the blue form is very close akin to C. Portia coerulea in every way.
There were other hybrids of Coleman's which were in the blue field but seemed to have been passed by or have passed on. Among these were C. Alcimeda coerulea (C. gaskelliana var. coerulescens x C. labiata var. coerulea), C. Blanche (C. labiata var. coerulea x C. maxima), C. Chloringiana (C. bowringiana var. lilacina x C. Chloris), C. Princess Helen Victoria (C. Ariel coerulea x C. maxima var. gigantea), Lc. Lillian Gilliat (Lc. Ophir x C. Alcimeda coerulea), and Lc. Portia-pumila (C. Portia coerulea x L. pumila).
Blue forms of Lc. Jericho (C. Remy Cholet x Lc. Erica Sander) have also appeared. This hybrid is a big question mark in my book. No information seems to be available on it. It is a well-shaped, large flowered, fine blue. It is somewhat difficult to breed, but some success has been attained.
Laeliocattleya Summer Haze (C. Porcia 'Cannizaro' x C. warneri var. coerulea) was an unsuccessful attempt at blue, but some off-colors appeared, reminiscent of the blue in C. warneri var. coerulea.
Laeliocattleya Blue Boy (C. Ariel coerulea 'Bodnant's' x Lc. elegans Werkhauserii') was perhaps the biggest breakthrough in recent times. The flowers are from three to five inches across with dark lips, most with the lavender bar, and have fine blue coloration throughout. This is one of today's principal breeders. They are very fertile and seedlings are strong growers.
Laeliocattleya Eximea (L. purpurata 'Werkhauserii' x C. warneri var. coerulea) and C. Olivia (C. trianae 'Blue Bird' x C. intermedia var. amethystina) are two crosses I have seen but a few of, and none have been very blue. Their pedigrees are such that at least a few blue forms would be expected.
Several crosses of Lc. Schilleriana have appeared of late. It has been interesting to note the really high percentage of lavender ones. Other L. purpurata 'Werkhauserii' crosses, i.e., Lc. Mariner (x C. Ariel coerulea) and Lc. Poor Paul (x C. Portia coerulea), are also giving lavenders along with blues. It leads one to speculate whether the best L. purpurata for breeding this color has yet been found.
Cattleya Undine (C. mossiae 'Reineckiana, Blue Lip' x C. intermedia var. coerulea) has white to very light blue sepals. The lip is veined a delicate clear blue. No lavender is apparent in most cases. The flowers are three to five inches across, two or three to a spike. They are proving very fertile and have been used for several crosses.
The cross of Epidendrum mariae x Lc. Blue Boy is a very interesting one. The idea behind it was probably to enhance the blue by using the green of the Epidendrum parent. The outcome has been flowers which are about three inches across with a Cattleya-type lip. They vary a great deal in petal size, shape, and lip coloration. Color varies from dark lavender to light rose with green undershading, and some blues.
Though not all blue hybrids are included in this article, the greatest majority of the blooming ones have been. Many more are on their way, in flask, flat, or pot. We can look forward to these new generations with high hopes for finer, clearer, darker blues.
(American Orchid Society Bulletin, Vol. 35, No. 11, November, 1966, pp. 915-916.)