To bloom before dying, the precarious life of twig epiphytes

A Dendrophylax that is in a piece of bark the tree has shed sends a root toward the nearest branch

A Miconia tree trunk showing the bark that is about to be shed.

This Leochilus is kept in place by its numerous roots even though
the base of the plant is not attached to the tree

In trees that don't shed their bark the branches can become literally
 carpeted with all manner of epiphytic plants

Tillandsia seedlings in a twig of an orange tree. 

A Campylocentrum has found a favorable spot on a branch and is fruiting heavily.  The Ionopsis on the smaller branch will probably fall along with the dead branch in which it is growing.

Most people picture the life cycle of epiphytic orchids as one that is fairly sedate.  They have the impression that once an orchid germinates in a tree it can spend decades growing and blooming seasonally with little change to its circumstances.   This is true for many species, but not for all.   In particular, the life of orchids that prefer to grow in twigs is a race to bloom before the tree sheds the bark or the twig dies.

Why would an orchid grow under such precarious circumstances?  My own guess is that these orchids are exploiting a niche where they face little competition from other plants.    I have observed that the local orchids sometimes develop such extensive root systems that they alone can keep the plant attached to the tree when the twig or branch dies.  Also, they seem to bloom while quite small, no seven year wait to reach adult size and bloom with these orchids.  However even with all these adaptations life is precarious for these orchids, if one walks on the forest after a particularly windy storm it is common to find fallen twigs often with Ionopsis orchids on them.  In the forest around my house you can find Dendrophylax, Ionopsis, Campylocentrum and Leochilus in the branches of Miconia and Guava trees.

Bulbophyllum angustifolium (Blume) Lindley (1830), a miniature botanical curiosity that is quite floriferous

In this photo you can see the long internodes between pseudobulbs

I got this tiny plant as a gift from a friend.  It is a twig epiphyte of the mountainous areas of Thailand, Malaya and Java¹.  This is a plant that is smaller than most commercially available Bulbophyllum, its pseudobulbs less than an inch tall, they are thin and the leaf is much larger than the pseudobulb.  The pseudobulbs are widely spaced along a rambling stem.

I didn’t put this plant in its own mount or pot.  My friend’s plant was an untidy tangle of stems going in every direction around and under a slated basket.  I decided to put the orchid on the top of a basket where a plant of Bulbophyllum Elizabeth Ann was growing so that it could ramble to its heart’s content.  Potting this plant would have is an exercise in futility as, due the long internodes the new growths surely would  end up out of the pot unless a grossly inpractical and oversized pot was used.  The plant grew well and eventually started growing out of the basket.  I kept twisting the stems back to the sides of the basket, because otherwise they grew out into the air.  My plant bloomed profusely with many inflorescences at the same time.

Sadly, I lost this plant.  I lost in a particularly embarrassing way.  Since the plant was growing and blooming well I assumed that it didn’t need much attention, but, as happened to me with other Bulbophyllum, eventually the pseudobulbs started growing away from the basket and into the air.  The result of this was that the stems were hanging from the basket, held back only by the older growths.  When the roots on the older growths died and decomposed, the pieces of the plant with the newest pseudobulbs would fall to the ground where they would lie unnoticed among the leaf litter only to be swept away when I passed the leaf blower.  That is a hazard with this plant, because all the parts of the plant are small and comparatively thin, it is easy to miss it if a piece falls from the mount.

One day I checked the basket and discovered that all the stems were old or dead and none had an active growing tip.   My advice on this plant is to mount it on a plaque that allows it to roam at will but never neglect the task of bending back the new growths that are growing into the air so that they are back in contact with the mount.    This plant grew well under my environmental conditions which are pretty humid during the rainy season.  The inflorescence of this orchid is short and the flowers are small.  The flowers are white with yellow tips.  Although this plant is small it can produce a nice showing when in full bloom, particularly if it has many pseudobulbs.  It is not common among local growers.

¹ Siegerist, Emily S.  2001.  Bulbophyllum and their allies: a grower’s guide