Monday, January 16, 2017

Dendrobium kingianum: the pink rock orchid

Dendrobium kingianum
Dendrobium kingianum is an Australian species popular among orchid growers. I love the delicate coloring of these flowers, and hybridizers must have too; Dendrobium kingianum has provided either the pollen or the seed to 158 registered crosses!

In its natural environment, Dendrobium kingianum usually grows in or around rocks (as a lithophyte), across much of eastern Australia, covering many habitats and weather patterns. I suspect that this variety of natural growth conditions is why Dendrobium kingianum is reputedly easy to grow in culture.
Closeup of Dendrobium kingianum flowers
Dendrobium kingianum flowers are about 1 inch across.  Lavender varieties like the one I photographed at the Bronx Botanical Garden are the most common.  However, flowers can range from white to deep purple. Australian Native Plants Society has some beautiful photos of purple and white varieties.

Dendrobium kingianum culture notes. (Massachusetts Orchid Society)

Saturday, January 7, 2017

What causes a phalaenopsis to grow a keiki?

Phalaenopsis keikis: Noid Phal keiki on left, Phal Gold Tris keiki on right
Happy 2017 everyone! December/January tend to be a colorful time for orchids in my terrarium.  The shorter, colder days of September provide the perfect signal to induce my Phals to spike.  The flower spikes generally develop over the next two months, and come into full bloom around the turn of the new year.

However, this year, some of my spikes started growing aerial plantlets (or keikis) in addition to flower buds.  The keiki on my noid phal looks like a leaf growing off the side of a new flower spike.  Meanwhile, Phal Gold Tris produced a tiny plantlet at the tip of an old spike that bloomed over the Summer.

I have written about growing and separating phalaenopsis keikis in the past, but this time I was curious about what caused my orchids to produce keikis in the first place.

What causes a phalaenopsis to grow a keiki?

The internet has many claims about what causes an orchid to make a keiki, but offers little evidence in support.  And even in the research literature, I struggled to find a definitive answer.

So what do we know about Phalaenopsis keikis?  I found a common claim that if a phalaenopsis with a new spike (<4 inches) is exposed to temperatures above 28C (82F), then the spike will develop keikis instead of flower buds.  

See examples:
if a plant with a young inflorescence (less than 4 inches or 10 cm) is subsequently grown at 82 F (28 C) or higher, a spike can form a vegetative air plantlet known as a “keiki” instead of flower buds, buds may abort or both. (Phals article from  
"if a plant with an inflorescence <10cm is subsequently grown at 28C or higher for extended periods, a spike can form a vegetative air plantlet referred to as a "keiki" instead of flower buds, buds may abort, or the stem may elongate indefinitely without open flowers [Sakanishi et. al 1980]"  (Roberto G. Lopez and Erik S. Runkle, 2005)
However, when I tried to find the original source for this claim, its evidence is weak.  Sakanishi et al is a 1980 paper describing the Effect of Temperature on Growth and Flowering of Phalaenopsis amabilis. However, this paper never actually reported any keikis!

In fact, the authors found that high temperatures caused flower spikes to abort growth and flowering.
With the object of determining the effect of high temperature treatment started from the different stages of stalk elongation, 12 plants in the greenhouse were shifted to minimum 28C at each time when flower stalks reached a length of 5, 10, 21-30, and 41-50 cm.  The high temperature from the 5cm stage caused the abortion of florets or the stunted growth of the flower stalks. After the stalks elongated more than 10cm, every stalk normally developed into flower even at the high temperature.
 In the closing remarks, the paper references an even older study on Phalaenopsis schilleriana, which makes the claim about keikis being triggered by temperature.
At ...(maximum temperature 29-34C; minimum temperature 24-25C), [Phalaenopsis schilleriana]  adult plants develop a stalk, which remains vegetative and develops an adventive plant.           (De Vries JT, 1953)
This paper "On the flowering of Phalaenopsis schilleriana" dates back to 1953, and is not available online.  Thus we only have a second-hand description of its findings from the Sakanishi paper.  However, it appears to be the sole parent of all the claims regarding temperature control inducing keiki formation.

What does keiki paste do?

A number of companies sell a product called "keiki paste" which when applied to a dormant node on a flower spike can help induce growth of a keiki.  The active ingredient of keiki paste is a chemical called BAP, or benzyl adenine.  BAP is a synthetic plant growth hormone.  It stimulates activity from flower spikes, and can produce either flowers or keikis depending on environmental conditions.

Which still does not answer our original question about what conditions make a Phalaenopsis develop a keiki instead of flowers.

The final verdict?

I don't think we actually really know the answer to this question. 

Orchid research is not particularly interested in this question. Commercial growers optimize conditions to produce flowers, not keikis.  And keikis are an inefficient way to reproduce orchids on a commercial scale, leaving little incentive to study keikis when there are important questions to be worked out in meristem cloning and in vitro seed germination techniques. 

If anyone reading this has come across a different claim about phalaenopsis keikis, I'd be happy to look into whether it has a scientific backing.  However, in the meantime, I don't think we know what cocktail of light/temperature/water/nutrients is the Goldilocks recipe to trigger keiki growth.

Monday, December 12, 2016

A crossing of two giants: Rhynvandopsis Memoria Mary Nattrass

Rhynvandopsis Memoria Mary Nattrass (aka Opsistylis)
This orchid is absolutely one of my favorite flowers.  I love the sharp contrast of the patterning on these large waxy flowers. Rhynvandopsis Memoria Mary Nattrass is a primary hybrid between Vandopsis gigantea and Rhynchostylis gigantea, registered in 1972.

Parentage of Rhynvandopsis Memoria Mary Nattrass
Image credits:
Vandopsis gigantea , by Malcolm Manners, Wikimedia Commons image
Rhynchostylis gigantea by Elena Gaillard, Wikimedia Commons image
The parent species are themselves large and showy orchids.  Vandopsis gigantea reportedly has leaves that can reach half a meter in length, while Rhynchostylis gigantea can produce as many as 50 flowers on each inflorescence. 

Interestingly, Rhynchostylis gigantea comes in a great number of variants--the flowers can be white, pink, peach or wine colored, with very different amounts of speckling. This variability translates to Rhynvandopsis Memoria Mary Nattrass as well, which can have different hues and color patterns depending on which variant of Rhynchostylis gigantea was used to generate a given hybrid.

More images of the stunning Rhynvandopsis Memoria Mary Nattrass:

Friday, November 25, 2016

Vanda Roslyn Rogers

Vanda Roslyn Rogers
Vanda Roslyn Rogers is a large pinkish flower, registered in 1990 as a cross between Vanda Fuchs Indigo, and Vanda Yip Sum Wah.  However, unlike the more popular 90's cross Vanda Pachara Delight (which shares 5 out 6 species progenitors in common), this hybrid did not have the same staying power.  Searches for "Vanda Roslyn Rogers" yield few results, most of them referring to people named Roslyn.

The genealogy diagram for Vanda Roslyn Rogers is shown below.  (Link to a larger image view)
Genealogy of Vanda Roslyn Rogers
Just like V. Pachara Delight, the genealogy of V. Roslyn Rogers is dominated by two key Vanda species: Vanda coerulea and Vanda sanderiana. In total, there are 27 crossings depicted in this diagram. V. coerulea provided either the pollen or the seed in 6 of them (22%), and V. sanderiana played a direct part in 13 of the crosses (48%).  

These are the 6 species that contributed to making Vanda Roslyn Rogers.
Species Progenitors of Vanda Roslyn Rogers
Photo credits:
Vanda sanderiana (original image, by Dalton Holland Baptista, Wikimedia commons)
Vanda coerulea (original image, by  Association Auboise d'Orchidophilie Exotique)
Vanda dearei (original image, by Rachmat Setlawan Saleh (Flickr gallery))
Vanda luzonica (original image,  by Akatsuka Orchid Gardens (orchid vendor site)
Vanda tricolor (original image, by Association Auboise d'Orchidophilie Exotique)
Vanda curvifolia (original image, by Association Auboise d'Orchidophilie Exotique)

Personally, I prefer the look of these parent species over the resulting hybrid.  However, it was interesting to see how two relatively similar family trees (Vanda Pachara Delight vs Vanda Roslyn Rogers) produced rather different looking flowers.

Monday, October 24, 2016

A classic blue orchid: Vanda Pachara Delight

Vanda Pachara Delight
Blue is a rare shade among cultivated orchids.  A few wild orchid species achieve that rare hue, but the only true blue cultivated orchid was created by genetic engineering in a Japanese lab in 2013. The gorgeous Phal has since been shown at a number of orchid shows, but don't expect to find one for sale at your favorite nursery any time soon.

In the meantime, Vandas dominate the field of the almost-blue orchid.  Vanda Pachara Delight is one such popular hybrid.  The orchid's flowers are a deep due of purple-blue, although the shade is difficult to photograph accurately.  Registered almost 2 decades ago in 1999, this hybrid is still often found blooming in stores and greenhouses.  Pachara Delight has since been used to make two more hybrids: Vanda Jan Marie Ryan, and Vandachostylis Mak Ho Seng.

Vanda Pachara Delight
Vanda Pachara Delight is a cross between Vanda Gordon Dillon, and Vanda Karulea. The whole genealogy is depicted below. (Full size image)

Genealogy of Vanda Pachara Delight
What stands out the most in this breeding scheme is how prominently Vanda sanderiana features in the genealogy.  There are 22 crossings in this image, and Vanda sanderiana is involved in 50% of them. Vanda coerulea, the second most important contributor to the breeding, accounts for 20% of the crosses. In fact, the primary hybrid of V. sanderiana and V. coerulea (Vanda Rothschildiana) already looks very similar to Vanda Pachara Delight.  
Vanda Rothschildiana (1931)
Photo Credit: Guillaume Paumier (link to original image on Wikimedia commons)

Three other species (V. dearei, V. luzonica, and V. tricolor) contributes to the mix. 
Species progenitors of Vanda Pachara Delight
Photo credits:
Vanda sanderiana (original image, by Dalton Holland Baptista, Wikimedia commons)
Vanda coerulea (original image, by  Association Auboise d'Orchidophilie Exotique)
Vanda dearei (original image, by Rachmat Setlawan Saleh (Flickr gallery))
Vanda luzonica (original image,  by Akatsuka Orchid Gardens (orchid vendor site)
Vanda tricolor (original image, by Association Auboise d'Orchidophilie Exotique)

Saturday, September 24, 2016

What is a phalaenopsis? It might not be what you think

Phalaenopsis display at the 2016 New York Orchid Show

What is a Phalaenopsis?  If you are an orchid enthusiast, then at first this question might seem a little too simple.  After all, the Phalaenopsis is probably the most iconic orchid.  If you search google images for 'orchid', 7 out of the first 10 image results depict Phalaenopsis flowers. It's what I first think of when someone says 'orchid'.
What a Phalaenopsis orchid typically looks like: Phalaenopsis OX Black Face 'OX 1647'

What we typically refer to as a "Phalaenopsis orchid" are the myriad hybrids that belong to the Phalaenopsis genus. This classification encompasses approximately 60 species. Also known as the 'Moth orchid' or the 'Butterfly orchid' they are a colorful, varied, long-flowering and easy-to-grow plants that are a favorite among hobbyists and breeders alike. There are more than 35,000 Phalaenopsis hybrids listed in the International Orchid Registry, and nearly 100 new hybrids are added every month!

However, over time, I've come across orchid species that bear the name "phalaenopsis" which do not actually have much relation at all to the Moth Orchid.  

I wanted to find out, just how many such orchid species are named 'phalaenopsis'? Turns out there are Four. 

Bulbophyllum phalaenopsis
Caucaea phalaenopsis
Dendrobium phalaenopsis
Miltoniopsis phalaenopsis

This made me curious about what these orchids might have in common that they all earned the same species name?  Do they resemble the Moth orchid more than other species in their genus?  I decided to briefly profile each of these "Not phalaenopsis" phalaenopsis species and see what came up.

Bulbophyllum phalaenopsis
These flowers are weird. They look nothing like the Phalaenopsis genus, and app they smell like "dead, rotting mice".  Turns out this orchid was named not for its flowers, but rather for its large leaves. This species was discovered in 1937 in New Guinea.

Bulbophyllum phalaenopsis
Image credit: Image,  by Orchidgalore (Flickr gallery)
Bulbophylum phalaenopsis
Image credit: Image, Stefano (Flickr gallery)

Caucaea phalaenopsis (aka Oncidium phalaenopsis)
Before today, I've never even heard of an orchid genus called "Caucaea". These orchids are closely related to Oncidiums.  In fact Caucaea and Oncidium are so closely related, that "Oncidium phalaenopsis" is another name for the same species. Caucaea phalaenopsis grows at high elevations in Ecuador, where it was first described in 1869.
Caucaea phalaenopsis (aka Oncidium phalaenopsis)
Image credit: Image, by Dogtooth77 (Flickr gallery)
If I squint and ignore the typical oncidium flower shape, I can definitely see how the color pattern of these flowers evokes those of Phalaenopsis hybrids.

Dendrobium phalaenopsis
This is clearly another species that was named for its resemblance to common phalaenopsis hybrids. This species goes under a number of different names, including Dendrobium biggibum, Vappodes phalaenopsis, The Cooktown Orchid, and The Mauve Butterfly Orchid. This orchid is native to Queensland Australia, where it was discovered in 1852.
Dendrobium phalaenopsis
Image credit: Image, by Stefano (Flickr gallery)

Miltoniopsis phalaenopsis (aka Miltonia phalaenopsis)
This flower has almost the same color patterning as Caucaea phalaenopsis, and likely was similarly named for that reason. It was discovered in the cloud forests of Colombia in 1854.
Miltoniopsis phalaenopsis (aka Miltonia phalaenopsis)
Image credit: Image, by Quimbaya (Flickr gallery)
While none of these flowers are perfect doppelgangers of the Phalaenopsis genus, they clearly do have enough features in common to explain why they were named this way. 

Sunday, September 18, 2016

Oncidopsis Memoria Martin Orenstein 'Lulu'

Oncidopsis Memoria Martin Orenstein 'Lulu'
Oncidopsis orchids are hybrids between Oncidium and Miltoniopsis.  This particular hybrid gracefully displays the balance between these two genera: its flowers have the full roundness typical of Miltoniopsis, yet they also display an intensity of color and pattern that reminds me of Oncidium crosses.

Oncidopsis Memoria Martin Orenstein is a 1992 hybrid between Oncidopsis Aglaon and Miltoniopsis Martin Orenstein. It's actually a slightly unusual crossing, because Oncidopsis Aglaon is a very old hybrid: it was registered in 1926.  Such old hybrids don't frequently maintain popularity long enough to still be available for hybridizing nearly a century after their creation.

Genealogy of Oncidopsis Memoria Martin Orenstein
You can see a full resolution version of this image here:

As is typical with orchid hybrids, the breeding scheme for Oncidopsis Memoria Martin Orenstein is a bit of an overcomplicated mess. There are approximately 50 progenitors in the diagram, including 5 Oncidium species and 3 Miltoniopsis species.  

Miltoniopsis breeding clusters very strongly around Miltoniopsis Bleuana, a primary hybrid of M. vexillaria and M. roezlii. Interestingly, this orchid goes by two different names.  M. Bleuana was the first and oldest Miltoniopsis hybrid; it was registered in 1889 and named after its maker, Alfred Bleu.  However, in 1921, the exact same cross was again registered under a different name: M. Reine Elisabeth

The reason for all this Miltoniopsis interbreeding is that in the 1800s, orchids of this genus were in very high demand, but botanists' ability to hybridize them was quite limited. There were only 2 possible primary hybrids for botanists to work with: Miltoniopsis Bleuana [roezlii x vexillaria] and Miltoniopsis Venus [phalaenopsis x vexillaria].  It took another half century to discover many of the Miltoniopsis species we know today, and then more time for breeders to generate new primary Miltoniopsis hybrids in the 1990's.  Until then, overzealous Miltoniopsis breeders kept generating endless variants of the same few basic crosses.

Species progenitors of Oncidopsis Memoria Martin Orenstein
Photo credits: 
Oncidium harryanum by Diego Rodriguez (Flickr gallery)
Miltoniopsis roezliiby Strohero (wikimedia commons)
Miltoniopsis phalaenopsisWikimedia commons image

Here are the Orchid species that went into creating Oncidopsis Memoria Martin Orenstein.  These are all a familiar list of suspects that have contributed in various combinations to most other Oncidium and Miltoniopsis hybrids I've profiled: Oncidium alexandre, Oncidium nobile, Oncidium luteopurpureum, Oncidium harryanum, Miltoniopsis vexillaria, Miltoniopsis roezlii, and Miltoniopsis phalaenopsis.

The lip coloration of Miltoniopsis phalaenopsis shows up in the final hybrid.  Likewise the purple of Miltoniopsis vexillaria comes through, as does the slightly more ruffled flower shape of Oncidium alexandre and Oncidium nobile. It remains a mystery to me what any of the other oncidium species might have contributed to this cross, or whether their traits have been effectively bred out of the orchid during the hybridization process.