Is Dendrobium x Bulbophyllum possible?
 

They are in the same tribe, so I was wondering if it is possible to get a cross between Dendrobium and Bulbophyllum.

Has this been attempted before?

A tribe is, in taxonomy, something localted between the genus and family.
So that you can understand, the family of the mammals has 1258 genera.

Not possible. There are Dendrobiums that can't be crossed with other Dendrobiums, much less other genera!

Bulbophyllum and Dendrobium aren't even the same tribe. The term "tribe" refers to closely-related genera, some of which will interbreed. So the Cattleya tribe includes Laelia, Sophronitis, Epidendrum, Encyclia, Barkeria, etc. Some of the genera have been lumped into Cattleya since DNA indicates that they are not really separate... a matter of criteria. Other than both being orchids, Bulbophyllum and Dendrobium are not closely related at all. Such a cross would not be even remotely possible.

There is one registered cross of a Bulbophyllum x Dendrobium: Bulborobium Chitchote

2006, Bulb. putidum x Den. Anucha Flare by T.Chitchote

Woah! I just googled that and it seems that it exists!
Unfortunately, I couldn't find any images of it.

Another "Whoa":

Just because the cross is registered does not mean it's real.

The existence of a registration indicates someone went to the trouble of creating a document and submitting it and the fee to the registrar, and that it was accepted at face value.

The documented "facts" might be true, might simply be a mistake - assuming one plant was the source of the pollen in a "volunteer" capsule - or might be completely falsified.

That's certainly a "woah", I never knew you could register a plant that doesn't exist.

Now I'm interested in this - have there been any definite cases of fake registered plants?

Info from RHS 2006 supplement:

REGISTRAR’S NOTES
A new hybrid between Bulbophyllum and Dendrobium
The novel hybrid Bulborobium (Bulbophyllum x Dendrobium) may occasion some comment as these two genera along with their
satellites, have been maintained in different breeding groups (Dendrobium in Gp.3 and Bulbophyllum in Gp.11). Both these gen-
era are very large with c. 900 species and 1200 species respectively, and partly as a consequence, breeding activity has con-
centrated on hybrids within each of the two genera with little incentive to produce intergenerics. For example, Dendrobium is the
basis of a major industry for pot-plants and cut flowers and just over 10 000 hybrids have been registered to date.
However, after careful investigation the registration, (Bulb. putidum x Den. Anucha Flare) upon which this new hybrid genus is
based, has been accepted. This will require the merger of the two breeding groups involved.
Reasons for accepting this hybrid include:
1. The taxonomic position of the two genera. Both genera are regarded as sister genera within the Dendrobieae, with
Dendrobiinae containing Dendrobium and satellites, and Bulbophyllinae containing Bulbophyllum and its satellites. The two sub-
tribes share several significant features including, naked pollinia, chromosome number, seed type, and general floral form
(Dressler, 1993, Phylogeny and classification of the orchid family, p. 202-204). This close relationship is upheld by recent molec-
ular work as discussed in Genera Orchidacearum 4: 5-6 (2005), which comments that ‘Dendrobieae [is] exactly as circum-
scribed by Dressler (1993)’, adding that the Dendrobiae is ‘so morphologically distinctive that that it would have been a great
surprise to find that [it was] not clearly identified in the DNA analyses.’ Mention is also made of ‘velamen of the Dendrobium-
Bulbophyllum type’, further indicating a close relationship.
Breeding Groups usually match closely clusters of sub-tribes as upheld by both Dressler and later molecular work, which means
in practical terms that hybrids between some Dendrobium and Bulbophyllum should be expected. This is well established with
other Breeding Groups containing groups of comparable taxonomic distance that are known to interbreed such as the subtribes
containing Cymbidium (Cyrtopodiinae) and Catasetum (Catasetinae) within the tribe Cymbidieae.
Asiatic Bulbophyllum appear to be fly pollinated and exhibit various sapromyophilous pollination syndromes, whereas
Dendrobium are mostly bee pollinated. As a consequence of the elaborate pollination systems there is no need for other mecha-
nisms of incompatibility to retain generic identities, hence it should not be surprising that hybrids between elements within the
two genera are possible.
2. Comparison of the photographs of the hybrid with both parents. Scrutiny of the images provided by the breeder indicate a
flower that has features intermediate between the two putative parents. The flower most resembles the Dendrobium parent in
colour and general appearance, which is stated to be the pollen parent. The breeder has since confirmed that the seed parent
was definitely the Bulbophyllum which is very strong evidence in favour of a genuine hybrid. Some other features of interest
include; inheritance of the long lateral sepals from the Bulbophyllum parent, as elongated but reduced (by comparison) sepals in
the hybrid which is consistent with the inheritance of similar features in other hybrids, compare for example, the inheritance of
petal tails from Paphiopedilum sanderianum. Characters that relate to highly specialised pollinator shifts are not likely to domi-
nate in a hybrid. The distance between the lip and column in the hybrid is much greater than in the Dendrobium parent and
reflects the Bulbophyllum flower, as does the shape of the labellum.
3. Comparison with some of the Dendrobium hybrids in the immediate ancestry of Den. Anucha Flare, and the results of selfing
these hybrids, suggest that the shape of the hybrid flower is more than would be expected from segregation due to accidental
selfing of Anucha Flare, which can be discounted if the seed was harvested from the Bulbophyllum parent as claimed. See for
example the photographs of segregates resulting from selfing Den. Theodore Takiguchi, Kamemoto et al., Breeding Dendrobium
orchids in Hawaii, 1999: 92.
The breeder Mr Thitipas Chitchote of Thailand, kindly responded to enquiries, explaining that only 15 seeds were obtained from
the pod on the Bulbophyllum, and that most seedlings were still in flasks. Other Bulbophyllum x Dendrobium have been made
and other growers have produced viable seeds and have seedlings at flask stage or beyond, including Bulb. appendiculatum x
Den. pulchellum. The hybrid that flowered was pollinated on 28th November 2004 and flowered on the 9th September 2006.
The choice of Dendrobium Anucha Flare as a parent in this cross is an interesting one, which has likely been an important factor
in its success. This hybrid combines three sections, Phalaenanthe, Spatulata and Latouria, and seven species (though Den.
phalaenopsis predominates) within Dendrobium, providing a broad genome. Parallel situations in other breeding groups have
shown that this is more likely to result in viable seed than a cross between two species in different genera.
Breeding Group 3 will now be regarded as consisting of Bulbophyllum s. l. and Dendrobium s. l., along with their satellite genera
such as Flickingeria and Sunipia. This is an adjustment to the list of breeding groups as it appears in The handbook on orchid
nomenclature and registration 4th ed. 1993: 50-51

WTF!? I rarely feel shocked with orchids anymore, but this definitely makes my jaw drop!!