November 2, 2011 • 11:11 am

The Adenium in my office has finally bloomed, after three years (I’m not sure of the species, but I think it’s A. obesum):

And one of my orchids, the Paphiopedilum spicerianumhas four flowers at once.  I love this one because the flowers look like the faces of little gnomes (click to enlarge).  Given its shape, I suspect it’s an insect mimic and is pollinated by pseudocopulation:

27 thoughts on “Flowers!

  1. The bottom of the Adenium is almost reminiscent of a miniature Baobab.

    Congrats on the Paph, too. Wasn’t there an animation with a character based on that sort of flower? Fantasia? Or some version of Alice in Wonderland?

    1. Would have added this before if had remembered the name at the time. Of a small handful of orchids that I have, this one is currently blooming, and the blossom seems similar to a Paph at arms length.

      But really it’s a hybrid of two species in separate genera, neither of which is a Paph, which raises a question I hadn’t thought of before:

      If you can produce a hybrid from different genera, should they really be separate?

      1. That is a really good question. Evolutionary biologists who study animals tend to think of reproductive isolation as something that evolves from genetic incompatibilities. This is present in many plants as well. But in some plants (and many animals as well), reproductive isolation is due entirely to physical isolating mechanisms- reproductive seasons that don’t overlap, extreme pollinator specificity, or things like that. Orchid genera are like that. Many genera are interfertile, but it takes a human to cross-pollinate them (usually).

        So maybe some zoologists would insist that hundreds of orchid species that are interfertile should be lumped. However, most currently recognized orchid species are clearly on their own evolutionary trajectories, with different habitat preferences, etc. If there are natural hybrids, they are rare.

        Genera are partly human constructs; it is an arbitrary decision how deeply we want to cut the branches of the phylogenetic tree to establish genera. But orchid genera are cut about as deeply as many other horticulturally important high-diversity plant genera, so they are about as old as many other genera.

        1. Thanks! As a biochemist, I’ve always been fairly content with the notion that “A taxon is whatever a taxonomist says it is.” But with the many taxa that get renamed based on this or that criterion, it just struck me that maybe some of these orchids have been assigned to separate genera based on old assumptions or criteria that now may not be as valid.

          1. Many orchid genera are being re-evaluated in light of DNA evidence. In some cases this has lead to lumping or splitting of previously recognised genera, in most it has confirmed the traditional classification. See Pridgeon et al., Genera Orchidacearum.

            As far as I know there are no hybrids of Paphiopedilum with species of other orchid genera.

            1. Gerardo Salazar and I just described a new orchid genus, Quechua (in press in Systematic Botany), and we based it on both morphology and DNA analysis. We made a special effort to be consistent with the depth of existing orchid genera in the phylogenetic tree. The single species of this genus was on its own branch of the tree, and this branch was much longer than the branch depth of other related genera.

              I think everyone nowadays puts as much or more emphasis on DNA as on morphology.

              This actually leads to some problems at the species level, because of some ingrained misconceptions in population genetics. It turns out that standard measures of genetic differentiation such as Fst or Gst are not really measuring differentiation, and so people have misunderstood the amount of differentiation observed between populations (as well as misunderstanding the process that produces the differentiation). But that is a longer post than I can fit here. If anyone is interested, see Jost 2008, Gst does not measure differentiation, Molecular Ecology 17: 4015-4026. It is behind a paywall but anyone can write me for a copy.

              I have not yet written much about the problem of defining species based on differentiation of neutral markers, but this paper explains that differentiation is locus-specific because it depends on mutation rate. There is no genome-wide differentiation (contrary to the classical view), so fast-mutating neutral markers cannot be used to judge the differentiation at the loci that count for evolution, the coding loci.

  2. Nice plants! But Paphiopedilum is not known to be pollinated by pseudocopulation. Rather, flies, bees, or beetles enter the pouch and end up wandering around inside the pouch (maybe gathering oils or such). When they try to get out, they are guided to the back of the pouch and try to get through one of the two narrow escape slots that you can see on either side of the column (the united male and female organs of orchids). As they try to get through one of those slots, they rub against the stigma, depositing pollen if they have some already on them, and then they have to rub against the sticky pollen on the anther that protrudes into the escape slot, putting pollen on their backs for the next flower to receive. I think that is more or less how it works.

  3. from wiki
    “The toxic sap of its roots and stems is used as arrow poison for hunting large game throughout much of Africa.”

    Watch out for cat nibbling.

  4. Congratulations on your Adenium blooming! I love those things. The really big ones (like on Socotra) are just amazing; I’ve only seen them in pictures, I wish I could go there some day.

  5. You waited three years for that? I’ll take a Joseph’s Coat (rose) any day… A wonderful yellow rose that sunburns red on the outer petals. In full bloom it is one of the most amazing roses you’ll ever see…

  6. How utterly and completely lovely. Both orchids challenge one’s ability to appreciate.

    The Adenium stem is every bit as beautiful as its flowers. I was also reminded of a baobab in miniature. What a delicious combination of colors: green, red and a charred brown.

    It is dull and chilly here today (or a perfect November day!). We’ve had occasional slants of sunlight and they turned the yellow leaves still clinging to the maples to near incandescence. Your pictures add to the many pleasures of the living world.


  7. Another orchid and succulent aficionado!

    The Adenium could be an aribicum/obesum hybrid as they sometimes bloom more frequently. I never could get any adenium to bloom however, living in the Pacific Northwest.

    Arid Lands Greenhouses has a great selection of desert plants and they do online ordering. I have an Adenia glauca from them and it’s doing well in the windowsill.

  8. Oh, I so share your taste in plants! But not your skill–I murdered the only Adenium I ever tried . . . sob.

    I noticed a spike on my Tolumnia orchid while watering the other day…

  9. Just started growing some Adenium from seed…only 2 (of 16) have germinated so far, but I think it’s funny how much the seedlings look like the adult plant…stumpy little things.

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