A dwarf white orchid flower from Central America, Epidendrum trialatum

A fascinating and lovely little orchid from Central America is the little known species Epidendrum trialatum. This species is interesting in that it possesses pure white crystalline flowers – an oddity for a genus that boasts blossoms of almost any color of the rainbow except pure white. It belongs to the group of Epidendrums known as reed stem orchids since the elongated cane or pseudobulb and alternating leaves looks something like a reed.

This is an epiphytic, dwarf evergreen orchid of warm tropical rain forests. It is a clump forming species with cane-like pseudobulbs ranging from 6-20 cm long at flowering size, and each holding between 3-5 leaves. These canes are somewhat zig-zag in shape, and are segmented with each bearing a sheath, short petiole, and one succulent leaf. The leaves are simple, elongate, blunt tipped, with a distinct midrib, each 3-10 cm long and 0.6-1.5 cm wide. They are a pleasant light apple green, and somewhat shiny. The roots are numerous, white, wiry, and branch less. Both canes and roots are borne off short, stout, and highly branched rhizomes.

The flowers of E. trialatum are its most startling feature. They are produced at the terminus of each cane only, borne singly or at most four (perhaps 5?) in number in a loose clump. The overall flower shape is typical for the genus, with a relatively large, broad lip that is bilobed, three sepals all similar in size and shape, and two very narrow, wire-like petals. Each flower is approximately 3 cm long vertically, and 2 cm across horizontally. The flowers are a pure, startlingly white color throughout. They are pungently sweet, with a hint of spice, and give off most of their fragrance at night.

This is an orchid of warm rain forests and deciduous forests on the Pacific side of Panama at altitudes between 500-1000 meters, as well as the Cordillera de Tilarán in Costa Rica. I can find no other reliable reports of it growing in other parts of Central or South America.

This dwarf orchid is remarkably similar looking to Epidendrum difforme, a species that was once considered a highly variable plant found throughout tropical America. In the 1980s and 1990s many of these forms (20 or more!) were partitioned out as separate entities, notably by Robert L. Dressler and Eric Hágsater, and now comprise a group known as the “Epidendrum difforme complex”. In fact it was Hágsater who described E. trialatum in 1984 as a new species from Panama. One of the distinguishing characteristics of this species is the hood that covers the column of the flower – it is frilled at the end, and its lateral lobes as well are serrated. See this link to view Kew’s specimen details on this species.

I first came across E. trialatum in Japan at the famous Grand Prix International Orchid Festival in Tokyo in 2010. I remember seeing an immense plant on display with perhaps a hundred stems, many bearing 2-5 snow white miniature flowers. That caught my eye, but not enough for me to take a picture for some reason. The plant was familiar enough – a dead ringer for an alba flowered form of E. difforme. The label confirmed my suspicion, reading, “Dendrobium difforme ‘white’“. Hmm, interesting. It even was awarded with a CHM (Certificate of Horticultural Merit) from the Japanese Orchid Growers Association (JOGA), so I figured it must be a valid name. It was only until I researched further that I found it was indeed a distinct species from E. difforme.

What is there to say about this plant, other than that it is the perfect specimen for orchid nuts who don’t have a lot of space? The pure white flowers are a delight, and though small, are produced in such great numbers that they put on a lovely show. Their odor is best sampled at night, and is nice enough in small whiffs, but you don’t want to take it in too deep – just a little too odd and spicy for that. Suffice it to say, you will easily smell the flowers if you are within arm’s reach.

I have found it to be completely undemanding in culture, needing only adequate humidity, moisture, and occasional fertilizer to thrive. I have my lone plant in a small clay pot loosely packed with sphagnum moss with broken crock for drainage. In winter it endures temperatures between 5-15 C for two or more months, also the time in which it flowers. In summer it goes outside, hanging in a plum tree and is subject to the vagaries of the local climate – tons of rain, heat, and wind. It takes this all in stride as long as it remains well watered. Avoid water logging the roots however. As with many fine rooted epiphytes, this plant responds well to drying between watering (which need to be frequent) as long as the humidity is high.

Ideally, it should be grown warmer year round, above 15 C. It should grow well mounted as it has been reported to grow on wooden fences in habitat. If grown in sharply drained compost in pots though, you are likely to grow a larger, more robust plant. A pot full of flowering stems is a sight worth seeing, and luckily not that difficult to accomplish. No direct sun on this one, and yet avoid too much shade as well – “Cattleya light” is perfect – diffuse and bright.

Although it seems a bit more rare in the states compared to Asia, you can source one if you look around. This is another wonderful little orchid that I highly recommend to anyone, particularly those interested in novelty species.